Quelle iccread.rs Sprache: unbekannt

// qcms
// Copyright (C) 2009 Mozilla Foundation
// Copyright (C) 1998-2007 Marti Maria
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the Software
// is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

use std::{
 convert::{TryInto, TryFrom},
 sync::atomic::AtomicBool,
 sync::Arc,
};

use crate::{
 double_to_s15Fixed16Number,
 transform::{set_rgb_colorants, PrecacheOuput},
};
use crate::{matrix::Matrix, s15Fixed16Number, s15Fixed16Number_to_float, Intent, Intent::*};

pub static SUPPORTS_ICCV4: AtomicBool = AtomicBool::new(cfg!(feature = "iccv4-enabled"));

pub const RGB_SIGNATURE: u32 = 0x52474220;
pub const GRAY_SIGNATURE: u32 = 0x47524159;
pub const XYZ_SIGNATURE: u32 = 0x58595A20;
pub const LAB_SIGNATURE: u32 = 0x4C616220;
pub const CMYK_SIGNATURE: u32 = 0x434D594B; // 'CMYK'

/// A color profile
#[derive(Default, Debug)]
pub struct Profile {
 pub(crate) class_type: u32,
 pub(crate) color_space: u32,
 pub(crate) pcs: u32,
 pub(crate) rendering_intent: Intent,
 pub(crate) redColorant: XYZNumber,
 pub(crate) blueColorant: XYZNumber,
 pub(crate) greenColorant: XYZNumber,
 // "TRC" is EOTF, e.g. gamma->linear transfer function.
 // Because ICC profiles are phrased as decodings to the xyzd50-linear PCS.
 pub(crate) redTRC: Option<Box<curveType>>,
 pub(crate) blueTRC: Option<Box<curveType>>,
 pub(crate) greenTRC: Option<Box<curveType>>,
 pub(crate) grayTRC: Option<Box<curveType>>,
 pub(crate) A2B0: Option<Box<lutType>>,
 pub(crate) B2A0: Option<Box<lutType>>,
 pub(crate) mAB: Option<Box<lutmABType>>,
 pub(crate) mBA: Option<Box<lutmABType>>,
 pub(crate) chromaticAdaption: Option<Matrix>,
 pub(crate) precache_output: Option<Arc<PrecacheOuput>>,
 is_srgb: bool,
}

#[derive(Debug, Default)]
#[allow(clippy::upper_case_acronyms)]
pub(crate) struct lutmABType {
 pub num_in_channels: u8,
 pub num_out_channels: u8,
 // 16 is the upperbound, actual is 0..num_in_channels.
 pub num_grid_points: [u8; 16],
 pub e00: s15Fixed16Number,
 pub e01: s15Fixed16Number,
 pub e02: s15Fixed16Number,
 pub e03: s15Fixed16Number,
 pub e10: s15Fixed16Number,
 pub e11: s15Fixed16Number,
 pub e12: s15Fixed16Number,
 pub e13: s15Fixed16Number,
 pub e20: s15Fixed16Number,
 pub e21: s15Fixed16Number,
 pub e22: s15Fixed16Number,
 pub e23: s15Fixed16Number,
 // reversed elements (for mBA)
 pub reversed: bool,
 pub clut_table: Option<Vec<f32>>,
 pub a_curves: [Option<Box<curveType>>; MAX_CHANNELS],
 pub b_curves: [Option<Box<curveType>>; MAX_CHANNELS],
 pub m_curves: [Option<Box<curveType>>; MAX_CHANNELS],
}
#[derive(Clone, Debug)]
pub(crate) enum curveType {
 Curve(Vec<uInt16Number>), // len=0 => Linear, len=1 => Gamma(v[0]), _ => lut
 /// The ICC parametricCurveType is specified in terms of s15Fixed16Number,
 /// so it's possible to use this variant to specify greater precision than
 /// any raw ICC profile could
 Parametric(Vec<f32>),
}
type uInt16Number = u16;

/* should lut8Type and lut16Type be different types? */
#[derive(Debug)]
pub(crate) struct lutType {
 // used by lut8Type/lut16Type (mft2) only
 pub num_input_channels: u8,
 pub num_output_channels: u8,
 pub num_clut_grid_points: u8,
 pub e00: s15Fixed16Number,
 pub e01: s15Fixed16Number,
 pub e02: s15Fixed16Number,
 pub e10: s15Fixed16Number,
 pub e11: s15Fixed16Number,
 pub e12: s15Fixed16Number,
 pub e20: s15Fixed16Number,
 pub e21: s15Fixed16Number,
 pub e22: s15Fixed16Number,
 pub num_input_table_entries: u16,
 pub num_output_table_entries: u16,
 pub input_table: Vec<f32>,
 pub clut_table: Vec<f32>,
 pub output_table: Vec<f32>,
}

#[repr(C)]
#[derive(Copy, Clone, Debug, Default)]
#[allow(clippy::upper_case_acronyms)]
pub struct XYZNumber {
 pub X: s15Fixed16Number,
 pub Y: s15Fixed16Number,
 pub Z: s15Fixed16Number,
}

/// A color in the CIE xyY color space
/* the names for the following two types are sort of ugly */
#[repr(C)]
#[derive(Copy, Clone)]
#[allow(clippy::upper_case_acronyms)]
pub struct qcms_CIE_xyY {
 pub x: f64,
 pub y: f64,
 pub Y: f64,
}

/// A more convenient type for specifying primaries and white points where
/// luminosity is irrelevant
struct qcms_chromaticity {
 x: f64,
 y: f64,
}

impl qcms_chromaticity {
 const D65: Self = Self {
 x: 0.3127,
 y: 0.3290,
 };
}

impl From<qcms_chromaticity> for qcms_CIE_xyY {
 fn from(qcms_chromaticity { x, y }: qcms_chromaticity) -> Self {
 Self { x, y, Y: 1.0 }
 }
}

/// a set of CIE_xyY values that can use to describe the primaries of a color space
#[repr(C)]
#[derive(Copy, Clone)]
#[allow(clippy::upper_case_acronyms)]
pub struct qcms_CIE_xyYTRIPLE {
 pub red: qcms_CIE_xyY,
 pub green: qcms_CIE_xyY,
 pub blue: qcms_CIE_xyY,
}

struct Tag {
 signature: u32,
 offset: u32,
 size: u32,
}

/* It might be worth having a unified limit on content controlled
* allocation per profile. This would remove the need for many
* of the arbitrary limits that we used */

type TagIndex = [Tag];

/* a wrapper around the memory that we are going to parse
* into a qcms_profile */
struct MemSource<'a> {
 buf: &'a [u8],
 valid: bool,
 invalid_reason: Option<&'static str>,
}
pub type uInt8Number = u8;
#[inline]
fn uInt8Number_to_float(a: uInt8Number) -> f32 {
 a as f32 / 255.0
}

#[inline]
fn uInt16Number_to_float(a: uInt16Number) -> f32 {
 a as f32 / 65535.0
}

fn invalid_source(mem: &mut MemSource, reason: &'static str) {
 mem.valid = false;
 mem.invalid_reason = Some(reason);
}
fn read_u32(mem: &mut MemSource, offset: usize) -> u32 {
 let val = mem.buf.get(offset..offset + 4);
 if let Some(val) = val {
 let val = val.try_into().unwrap();
 u32::from_be_bytes(val)
 } else {
 invalid_source(mem, "Invalid offset");
 0
 }
}
fn read_u16(mem: &mut MemSource, offset: usize) -> u16 {
 let val = mem.buf.get(offset..offset + 2);
 if let Some(val) = val {
 let val = val.try_into().unwrap();
 u16::from_be_bytes(val)
 } else {
 invalid_source(mem, "Invalid offset");
 0
 }
}
fn read_u8(mem: &mut MemSource, offset: usize) -> u8 {
 let val = mem.buf.get(offset);
 if let Some(val) = val {
 *val
 } else {
 invalid_source(mem, "Invalid offset");
 0
 }
}
fn read_s15Fixed16Number(mem: &mut MemSource, offset: usize) -> s15Fixed16Number {
 read_u32(mem, offset) as s15Fixed16Number
}
fn read_uInt8Number(mem: &mut MemSource, offset: usize) -> uInt8Number {
 read_u8(mem, offset)
}
fn read_uInt16Number(mem: &mut MemSource, offset: usize) -> uInt16Number {
 read_u16(mem, offset)
}
pub fn write_u32(mem: &mut [u8], offset: usize, value: u32) {
 // we use get() and expect() instead of [..] so there's only one call to panic
 // instead of two
 mem.get_mut(offset..offset + std::mem::size_of_val(&value))
 .expect("OOB")
 .copy_from_slice(&value.to_be_bytes());
}
pub fn write_u16(mem: &mut [u8], offset: usize, value: u16) {
 // we use get() and expect() instead of [..] so there's only one call to panic
 // intead of two
 mem.get_mut(offset..offset + std::mem::size_of_val(&value))
 .expect("OOB")
 .copy_from_slice(&value.to_be_bytes());
}

/* An arbitrary 4MB limit on profile size */
pub(crate) const MAX_PROFILE_SIZE: usize = 1024 * 1024 * 4;
const MAX_TAG_COUNT: u32 = 1024;

fn check_CMM_type_signature(_src: &mut MemSource) {
 //uint32_t CMM_type_signature = read_u32(src, 4);
 //TODO: do the check?
}
fn check_profile_version(src: &mut MemSource) {
 /*
 uint8_t major_revision = read_u8(src, 8 + 0);
 uint8_t minor_revision = read_u8(src, 8 + 1);
 */
 let reserved1: u8 = read_u8(src, (8 + 2) as usize);
 let reserved2: u8 = read_u8(src, (8 + 3) as usize);
 /* Checking the version doesn't buy us anything
 if (major_revision != 0x4) {
 if (major_revision > 0x2)
 invalid_source(src, "Unsupported major revision");
 if (minor_revision > 0x40)
 invalid_source(src, "Unsupported minor revision");
 }
 */
 if reserved1 != 0 || reserved2 != 0 {
 invalid_source(src, "Invalid reserved bytes");
 };
}

const INPUT_DEVICE_PROFILE: u32 = 0x73636e72; // 'scnr'
pub const DISPLAY_DEVICE_PROFILE: u32 = 0x6d6e7472; // 'mntr'
const OUTPUT_DEVICE_PROFILE: u32 = 0x70727472; // 'prtr'
const DEVICE_LINK_PROFILE: u32 = 0x6c696e6b; // 'link'
const COLOR_SPACE_PROFILE: u32 = 0x73706163; // 'spac'
const ABSTRACT_PROFILE: u32 = 0x61627374; // 'abst'
const NAMED_COLOR_PROFILE: u32 = 0x6e6d636c; // 'nmcl'

fn read_class_signature(profile: &mut Profile, mem: &mut MemSource) {
 profile.class_type = read_u32(mem, 12);
 match profile.class_type {
 DISPLAY_DEVICE_PROFILE
 | INPUT_DEVICE_PROFILE
 | OUTPUT_DEVICE_PROFILE
 | COLOR_SPACE_PROFILE => {}
 _ => {
 invalid_source(mem, "Invalid Profile/Device Class signature");
 }
 };
}
fn read_color_space(profile: &mut Profile, mem: &mut MemSource) {
 profile.color_space = read_u32(mem, 16);
 match profile.color_space {
 RGB_SIGNATURE | GRAY_SIGNATURE => {}
 #[cfg(feature = "cmyk")]
 CMYK_SIGNATURE => {}
 _ => {
 invalid_source(mem, "Unsupported colorspace");
 }
 };
}
fn read_pcs(profile: &mut Profile, mem: &mut MemSource) {
 profile.pcs = read_u32(mem, 20);
 match profile.pcs {
 XYZ_SIGNATURE | LAB_SIGNATURE => {}
 _ => {
 invalid_source(mem, "Unsupported pcs");
 }
 };
}
fn read_tag_table(_profile: &mut Profile, mem: &mut MemSource) -> Vec<Tag> {
 let count = read_u32(mem, 128);
 if count > MAX_TAG_COUNT {
 invalid_source(mem, "max number of tags exceeded");
 return Vec::new();
 }
 let mut index = Vec::with_capacity(count as usize);
 for i in 0..count {
 let tag_start = (128 + 4 + 4 * i * 3) as usize;
 let offset = read_u32(mem, tag_start + 4);
 if offset as usize > mem.buf.len() {
 invalid_source(mem, "tag points beyond the end of the buffer");
 }
 index.push(Tag {
 signature: read_u32(mem, tag_start),
 offset,
 size: read_u32(mem, tag_start + 8),
 });
 }

 index
}

/// Checks a profile for obvious inconsistencies and returns
/// true if the profile looks bogus and should probably be
/// ignored.
#[no_mangle]
pub extern "C" fn qcms_profile_is_bogus(profile: &mut Profile) -> bool {
 let mut sum: [f32; 3] = [0.; 3];
 let mut target: [f32; 3] = [0.; 3];
 let mut tolerance: [f32; 3] = [0.; 3];
 let rX: f32;
 let rY: f32;
 let rZ: f32;
 let gX: f32;
 let gY: f32;
 let gZ: f32;
 let bX: f32;
 let bY: f32;
 let bZ: f32;
 let negative: bool;
 let mut i: u32;
 // We currently only check the bogosity of RGB profiles
 if profile.color_space != RGB_SIGNATURE {
 return false;
 }
 if profile.A2B0.is_some()
 || profile.B2A0.is_some()
 || profile.mAB.is_some()
 || profile.mBA.is_some()
 {
 return false;
 }
 rX = s15Fixed16Number_to_float(profile.redColorant.X);
 rY = s15Fixed16Number_to_float(profile.redColorant.Y);
 rZ = s15Fixed16Number_to_float(profile.redColorant.Z);
 gX = s15Fixed16Number_to_float(profile.greenColorant.X);
 gY = s15Fixed16Number_to_float(profile.greenColorant.Y);
 gZ = s15Fixed16Number_to_float(profile.greenColorant.Z);
 bX = s15Fixed16Number_to_float(profile.blueColorant.X);
 bY = s15Fixed16Number_to_float(profile.blueColorant.Y);
 bZ = s15Fixed16Number_to_float(profile.blueColorant.Z);
 // Sum the values; they should add up to something close to white
 sum[0] = rX + gX + bX;
 sum[1] = rY + gY + bY;
 sum[2] = rZ + gZ + bZ;
 // Build our target vector (see mozilla bug 460629)
 target[0] = 0.96420;
 target[1] = 1.00000;
 target[2] = 0.82491;
 // Our tolerance vector - Recommended by Chris Murphy based on
 // conversion from the LAB space criterion of no more than 3 in any one
 // channel. This is similar to, but slightly more tolerant than Adobe's
 // criterion.
 tolerance[0] = 0.02;
 tolerance[1] = 0.02;
 tolerance[2] = 0.04;
 // Compare with our tolerance
 i = 0;
 while i < 3 {
 if !(sum[i as usize] - tolerance[i as usize] <= target[i as usize]
 && sum[i as usize] + tolerance[i as usize] >= target[i as usize])
 {
 return true;
 }
 i += 1
 }
 if false {
 negative = (rX < 0.)
 || (rY < 0.)
 || (rZ < 0.)
 || (gX < 0.)
 || (gY < 0.)
 || (gZ < 0.)
 || (bX < 0.)
 || (bY < 0.)
 || (bZ < 0.);
 } else {
 // Chromatic adaption to D50 can result in negative XYZ, but the white
 // point D50 tolerance test has passed. Accept negative values herein.
 // See https://bugzilla.mozilla.org/show_bug.cgi?id=498245#c18 onwards
 // for discussion about whether profile XYZ can or cannot be negative,
 // per the spec. Also the https://bugzil.la/450923 user report.
 // Also: https://bugzil.la/1799391 and https://bugzil.la/1792469
 negative = false; // bogus
 }
 if negative {
 return true;
 }
 // All Good
 false
}

pub const TAG_bXYZ: u32 = 0x6258595a;
pub const TAG_gXYZ: u32 = 0x6758595a;
pub const TAG_rXYZ: u32 = 0x7258595a;
pub const TAG_rTRC: u32 = 0x72545243;
pub const TAG_bTRC: u32 = 0x62545243;
pub const TAG_gTRC: u32 = 0x67545243;
pub const TAG_kTRC: u32 = 0x6b545243;
pub const TAG_A2B0: u32 = 0x41324230;
pub const TAG_B2A0: u32 = 0x42324130;
pub const TAG_CHAD: u32 = 0x63686164;

fn find_tag(index: &TagIndex, tag_id: u32) -> Option<&Tag> {
 for t in index {
 if t.signature == tag_id {
 return Some(t);
 }
 }
 None
}

pub const XYZ_TYPE: u32 = 0x58595a20; // 'XYZ '
pub const CURVE_TYPE: u32 = 0x63757276; // 'curv'
pub const PARAMETRIC_CURVE_TYPE: u32 = 0x70617261; // 'para'
pub const LUT16_TYPE: u32 = 0x6d667432; // 'mft2'
pub const LUT8_TYPE: u32 = 0x6d667431; // 'mft1'
pub const LUT_MAB_TYPE: u32 = 0x6d414220; // 'mAB '
pub const LUT_MBA_TYPE: u32 = 0x6d424120; // 'mBA '
pub const CHROMATIC_TYPE: u32 = 0x73663332; // 'sf32'

fn read_tag_s15Fixed16ArrayType(src: &mut MemSource, tag: &Tag) -> Matrix {
 let mut matrix: Matrix = Matrix { m: [[0.; 3]; 3] };
 let offset: u32 = tag.offset;
 let type_0: u32 = read_u32(src, offset as usize);
 // Check mandatory type signature for s16Fixed16ArrayType
 if type_0 != CHROMATIC_TYPE {
 invalid_source(src, "unexpected type, expected \'sf32\'");
 }
 for i in 0..=8 {
 matrix.m[(i / 3) as usize][(i % 3) as usize] = s15Fixed16Number_to_float(
 read_s15Fixed16Number(src, (offset + 8 + (i * 4) as u32) as usize),
 );
 }
 matrix
}
fn read_tag_XYZType(src: &mut MemSource, index: &TagIndex, tag_id: u32) -> XYZNumber {
 let mut num = XYZNumber { X: 0, Y: 0, Z: 0 };
 let tag = find_tag(&index, tag_id);
 if let Some(tag) = tag {
 let offset: u32 = tag.offset;
 let type_0: u32 = read_u32(src, offset as usize);
 if type_0 != XYZ_TYPE {
 invalid_source(src, "unexpected type, expected XYZ");
 }
 num.X = read_s15Fixed16Number(src, (offset + 8) as usize);
 num.Y = read_s15Fixed16Number(src, (offset + 12) as usize);
 num.Z = read_s15Fixed16Number(src, (offset + 16) as usize)
 } else {
 invalid_source(src, "missing xyztag");
 }
 num
}
// Read the tag at a given offset rather then the tag_index.
// This method is used when reading mAB tags where nested curveType are
// present that are not part of the tag_index.
fn read_curveType(src: &mut MemSource, offset: u32, len: &mut u32) -> Option<Box<curveType>> {
 const COUNT_TO_LENGTH: [u32; 5] = [1, 3, 4, 5, 7]; //PARAMETRIC_CURVE_TYPE
 let type_0: u32 = read_u32(src, offset as usize);
 let count: u32;
 if type_0 != CURVE_TYPE && type_0 != PARAMETRIC_CURVE_TYPE {
 invalid_source(src, "unexpected type, expected CURV or PARA");
 return None;
 }
 if type_0 == CURVE_TYPE {
 count = read_u32(src, (offset + 8) as usize);
 //arbitrary
 if count > 40000 {
 invalid_source(src, "curve size too large");
 return None;
 }
 let mut table = Vec::with_capacity(count as usize);
 for i in 0..count {
 table.push(read_u16(src, (offset + 12 + i * 2) as usize));
 }
 *len = 12 + count * 2;
 Some(Box::new(curveType::Curve(table)))
 } else {
 count = read_u16(src, (offset + 8) as usize) as u32;
 if count > 4 {
 invalid_source(src, "parametric function type not supported.");
 return None;
 }
 let mut params = Vec::with_capacity(count as usize);
 for i in 0..COUNT_TO_LENGTH[count as usize] {
 params.push(s15Fixed16Number_to_float(read_s15Fixed16Number(
 src,
 (offset + 12 + i * 4) as usize,
 )));
 }
 *len = 12 + COUNT_TO_LENGTH[count as usize] * 4;
 if count == 1 || count == 2 {
 /* we have a type 1 or type 2 function that has a division by 'a' */
 let a: f32 = params[1];
 if a == 0.0 {
 invalid_source(src, "parametricCurve definition causes division by zero");
 }
 }
 Some(Box::new(curveType::Parametric(params)))
 }
}
fn read_tag_curveType(
 src: &mut MemSource,
 index: &TagIndex,
 tag_id: u32,
) -> Option<Box<curveType>> {
 let tag = find_tag(index, tag_id);
 if let Some(tag) = tag {
 let mut len: u32 = 0;
 return read_curveType(src, tag.offset, &mut len);
 } else {
 invalid_source(src, "missing curvetag");
 }
 None
}

const MAX_LUT_SIZE: u32 = 500000; // arbitrary
const MAX_CHANNELS: usize = 10; // arbitrary
fn read_nested_curveType(
 src: &mut MemSource,
 curveArray: &mut [Option<Box<curveType>>; MAX_CHANNELS],
 num_channels: u8,
 curve_offset: u32,
) {
 let mut channel_offset: u32 = 0;
 #[allow(clippy::needless_range_loop)]
 for i in 0..usize::from(num_channels) {
 let mut tag_len: u32 = 0;
 curveArray[i] = read_curveType(src, curve_offset + channel_offset, &mut tag_len);
 if curveArray[i].is_none() {
 invalid_source(src, "invalid nested curveType curve");
 break;
 } else {
 channel_offset += tag_len;
 // 4 byte aligned
 if tag_len % 4 != 0 {
 channel_offset += 4 - tag_len % 4
 }
 }
 }
}

/* See section 10.10 for specs */
fn read_tag_lutmABType(src: &mut MemSource, tag: &Tag) -> Option<Box<lutmABType>> {
 let offset: u32 = tag.offset;
 let mut clut_size: u32 = 1;
 let type_0: u32 = read_u32(src, offset as usize);
 if type_0 != LUT_MAB_TYPE && type_0 != LUT_MBA_TYPE {
 return None;
 }
 let num_in_channels = read_u8(src, (offset + 8) as usize);
 let num_out_channels = read_u8(src, (offset + 9) as usize);
 if num_in_channels > 10 || num_out_channels > 10 {
 return None;
 }
 // We require 3in/out channels since we only support RGB->XYZ (or RGB->LAB)
 // XXX: If we remove this restriction make sure that the number of channels
 // is less or equal to the maximum number of mAB curves in qcmsint.h
 // also check for clut_size overflow. Also make sure it's != 0
 if num_in_channels != 3 || num_out_channels != 3 {
 return None;
 }
 // some of this data is optional and is denoted by a zero offset
 // we also use this to track their existance
 let mut a_curve_offset = read_u32(src, (offset + 28) as usize);
 let mut clut_offset = read_u32(src, (offset + 24) as usize);
 let mut m_curve_offset = read_u32(src, (offset + 20) as usize);
 let mut matrix_offset = read_u32(src, (offset + 16) as usize);
 let mut b_curve_offset = read_u32(src, (offset + 12) as usize);
 // Convert offsets relative to the tag to relative to the profile
 // preserve zero for optional fields
 if a_curve_offset != 0 {
 a_curve_offset += offset
 }
 if clut_offset != 0 {
 clut_offset += offset
 }
 if m_curve_offset != 0 {
 m_curve_offset += offset
 }
 if matrix_offset != 0 {
 matrix_offset += offset
 }
 if b_curve_offset != 0 {
 b_curve_offset += offset
 }
 if clut_offset != 0 {
 debug_assert!(num_in_channels == 3);
 // clut_size can not overflow since lg(256^num_in_channels) = 24 bits.
 for i in 0..u32::from(num_in_channels) {
 clut_size *= read_u8(src, (clut_offset + i) as usize) as u32;
 if clut_size == 0 {
 invalid_source(src, "bad clut_size");
 }
 }
 } else {
 clut_size = 0
 }
 // 24bits * 3 won't overflow either
 clut_size *= num_out_channels as u32;
 if clut_size > MAX_LUT_SIZE {
 return None;
 }

 let mut lut = Box::new(lutmABType::default());

 if clut_offset != 0 {
 for i in 0..usize::from(num_in_channels) {
 lut.num_grid_points[i] = read_u8(src, clut_offset as usize + i);
 if lut.num_grid_points[i] == 0 {
 invalid_source(src, "bad grid_points");
 }
 }
 }
 // Reverse the processing of transformation elements for mBA type.
 lut.reversed = type_0 == LUT_MBA_TYPE;
 lut.num_in_channels = num_in_channels;
 lut.num_out_channels = num_out_channels;
 #[allow(clippy::identity_op, clippy::erasing_op)]
 if matrix_offset != 0 {
 // read the matrix if we have it
 lut.e00 = read_s15Fixed16Number(src, (matrix_offset + (4 * 0) as u32) as usize); // the caller checks that this doesn't happen
 lut.e01 = read_s15Fixed16Number(src, (matrix_offset + (4 * 1) as u32) as usize);
 lut.e02 = read_s15Fixed16Number(src, (matrix_offset + (4 * 2) as u32) as usize);
 lut.e10 = read_s15Fixed16Number(src, (matrix_offset + (4 * 3) as u32) as usize);
 lut.e11 = read_s15Fixed16Number(src, (matrix_offset + (4 * 4) as u32) as usize);
 lut.e12 = read_s15Fixed16Number(src, (matrix_offset + (4 * 5) as u32) as usize);
 lut.e20 = read_s15Fixed16Number(src, (matrix_offset + (4 * 6) as u32) as usize);
 lut.e21 = read_s15Fixed16Number(src, (matrix_offset + (4 * 7) as u32) as usize);
 lut.e22 = read_s15Fixed16Number(src, (matrix_offset + (4 * 8) as u32) as usize);
 lut.e03 = read_s15Fixed16Number(src, (matrix_offset + (4 * 9) as u32) as usize);
 lut.e13 = read_s15Fixed16Number(src, (matrix_offset + (4 * 10) as u32) as usize);
 lut.e23 = read_s15Fixed16Number(src, (matrix_offset + (4 * 11) as u32) as usize)
 }
 if a_curve_offset != 0 {
 read_nested_curveType(src, &mut lut.a_curves, num_in_channels, a_curve_offset);
 }
 if m_curve_offset != 0 {
 read_nested_curveType(src, &mut lut.m_curves, num_out_channels, m_curve_offset);
 }
 if b_curve_offset != 0 {
 read_nested_curveType(src, &mut lut.b_curves, num_out_channels, b_curve_offset);
 } else {
 invalid_source(src, "B curves required");
 }
 if clut_offset != 0 {
 let clut_precision = read_u8(src, (clut_offset + 16) as usize);
 let mut clut_table = Vec::with_capacity(clut_size as usize);
 if clut_precision == 1 {
 for i in 0..clut_size {
 clut_table.push(uInt8Number_to_float(read_uInt8Number(
 src,
 (clut_offset + 20 + i) as usize,
 )));
 }
 lut.clut_table = Some(clut_table);
 } else if clut_precision == 2 {
 for i in 0..clut_size {
 clut_table.push(uInt16Number_to_float(read_uInt16Number(
 src,
 (clut_offset + 20 + i * 2) as usize,
 )));
 }
 lut.clut_table = Some(clut_table);
 } else {
 invalid_source(src, "Invalid clut precision");
 }
 }
 if !src.valid {
 return None;
 }
 Some(lut)
}
fn read_tag_lutType(src: &mut MemSource, tag: &Tag) -> Option<Box<lutType>> {
 let offset: u32 = tag.offset;
 let type_0: u32 = read_u32(src, offset as usize);
 let num_input_table_entries: u16;
 let num_output_table_entries: u16;
 let input_offset: u32;
 let entry_size: usize;
 if type_0 == LUT8_TYPE {
 num_input_table_entries = 256u16;
 num_output_table_entries = 256u16;
 entry_size = 1;
 input_offset = 48
 } else if type_0 == LUT16_TYPE {
 num_input_table_entries = read_u16(src, (offset + 48) as usize);
 num_output_table_entries = read_u16(src, (offset + 50) as usize);

 // these limits come from the spec
 if !(2..=4096).contains(&num_input_table_entries)
 || !(2..=4096).contains(&num_output_table_entries)
 {
 invalid_source(src, "Bad channel count");
 return None;
 }
 entry_size = 2;
 input_offset = 52
 } else {
 debug_assert!(false);
 invalid_source(src, "Unexpected lut type");
 return None;
 }
 let in_chan = read_u8(src, (offset + 8) as usize);
 let out_chan = read_u8(src, (offset + 9) as usize);
 if !(in_chan == 3 || in_chan == 4) || out_chan != 3 {
 invalid_source(src, "CLUT only supports RGB and CMYK");
 return None;
 }

 let grid_points = read_u8(src, (offset + 10) as usize);
 let clut_size = match (grid_points as u32).checked_pow(in_chan as u32) {
 Some(clut_size) => clut_size,
 _ => {
 invalid_source(src, "CLUT size overflow");
 return None;
 }
 };
 match clut_size {
 1..=MAX_LUT_SIZE => {} // OK
 0 => {
 invalid_source(src, "CLUT must not be empty.");
 return None;
 }
 _ => {
 invalid_source(src, "CLUT too large");
 return None;
 }
 }

 let e00 = read_s15Fixed16Number(src, (offset + 12) as usize);
 let e01 = read_s15Fixed16Number(src, (offset + 16) as usize);
 let e02 = read_s15Fixed16Number(src, (offset + 20) as usize);
 let e10 = read_s15Fixed16Number(src, (offset + 24) as usize);
 let e11 = read_s15Fixed16Number(src, (offset + 28) as usize);
 let e12 = read_s15Fixed16Number(src, (offset + 32) as usize);
 let e20 = read_s15Fixed16Number(src, (offset + 36) as usize);
 let e21 = read_s15Fixed16Number(src, (offset + 40) as usize);
 let e22 = read_s15Fixed16Number(src, (offset + 44) as usize);

 let mut input_table = Vec::with_capacity((num_input_table_entries * in_chan as u16) as usize);
 for i in 0..(num_input_table_entries * in_chan as u16) {
 if type_0 == LUT8_TYPE {
 input_table.push(uInt8Number_to_float(read_uInt8Number(
 src,
 (offset + input_offset) as usize + i as usize * entry_size,
 )))
 } else {
 input_table.push(uInt16Number_to_float(read_uInt16Number(
 src,
 (offset + input_offset) as usize + i as usize * entry_size,
 )))
 }
 }
 let clut_offset = ((offset + input_offset) as usize
 + (num_input_table_entries as i32 * in_chan as i32) as usize * entry_size)
 as u32;

 let mut clut_table = Vec::with_capacity((clut_size * out_chan as u32) as usize);
 for i in 0..clut_size * out_chan as u32 {
 if type_0 == LUT8_TYPE {
 clut_table.push(uInt8Number_to_float(read_uInt8Number(
 src,
 clut_offset as usize + i as usize * entry_size,
 )));
 } else if type_0 == LUT16_TYPE {
 clut_table.push(uInt16Number_to_float(read_uInt16Number(
 src,
 clut_offset as usize + i as usize * entry_size,
 )));
 }
 }

 let output_offset =
 (clut_offset as usize + (clut_size * out_chan as u32) as usize * entry_size) as u32;

 let mut output_table =
 Vec::with_capacity((num_output_table_entries * out_chan as u16) as usize);
 for i in 0..num_output_table_entries as i32 * out_chan as i32 {
 if type_0 == LUT8_TYPE {
 output_table.push(uInt8Number_to_float(read_uInt8Number(
 src,
 output_offset as usize + i as usize * entry_size,
 )))
 } else {
 output_table.push(uInt16Number_to_float(read_uInt16Number(
 src,
 output_offset as usize + i as usize * entry_size,
 )))
 }
 }
 Some(Box::new(lutType {
 num_input_table_entries,
 num_output_table_entries,
 num_input_channels: in_chan,
 num_output_channels: out_chan,
 num_clut_grid_points: grid_points,
 e00,
 e01,
 e02,
 e10,
 e11,
 e12,
 e20,
 e21,
 e22,
 input_table,
 clut_table,
 output_table,
 }))
}
fn read_rendering_intent(profile: &mut Profile, src: &mut MemSource) {
 let intent = read_u32(src, 64);
 profile.rendering_intent = match intent {
 x if x == Perceptual as u32 => Perceptual,
 x if x == RelativeColorimetric as u32 => RelativeColorimetric,
 x if x == Saturation as u32 => Saturation,
 x if x == AbsoluteColorimetric as u32 => AbsoluteColorimetric,
 _ => {
 invalid_source(src, "unknown rendering intent");
 Intent::default()
 }
 };
}
fn profile_create() -> Box<Profile> {
 Box::new(Profile::default())
}
/* build sRGB gamma table */
/* based on cmsBuildParametricGamma() */
#[allow(clippy::many_single_char_names)]
fn build_sRGB_gamma_table(num_entries: i32) -> Vec<u16> {
 /* taken from lcms: Build_sRGBGamma() */
 let gamma: f64 = 2.4;
 let a: f64 = 1.0 / 1.055;
 let b: f64 = 0.055 / 1.055;
 let c: f64 = 1.0 / 12.92;
 let d: f64 = 0.04045;

 build_trc_table(
 num_entries,
 // IEC 61966-2.1 (sRGB)
 // Y = (aX + b)^Gamma | X >= d
 // Y = cX | X < d
 |x| {
 if x >= d {
 let e: f64 = a * x + b;
 if e > 0. {
 e.powf(gamma)
 } else {
 0.
 }
 } else {
 c * x
 }
 },
 )
}

/// eotf: electro-optical transfer characteristic function, maps from [0, 1]
/// in non-linear (voltage) space to [0, 1] in linear (optical) space. Should
/// generally be a concave up function.
fn build_trc_table(num_entries: i32, eotf: impl Fn(f64) -> f64) -> Vec<u16> {
 let mut table = Vec::with_capacity(num_entries as usize);

 for i in 0..num_entries {
 let x: f64 = i as f64 / (num_entries - 1) as f64;
 let y: f64 = eotf(x);
 let mut output: f64;
 // Saturate -- this could likely move to a separate function
 output = y * 65535.0 + 0.5;
 if output > 65535.0 {
 output = 65535.0
 }
 if output < 0.0 {
 output = 0.0
 }
 table.push(output.floor() as u16);
 }
 table
}
fn curve_from_table(table: &[u16]) -> Box<curveType> {
 Box::new(curveType::Curve(table.to_vec()))
}
pub fn float_to_u8Fixed8Number(a: f32) -> u16 {
 if a > 255.0 + 255.0 / 256f32 {
 0xffffu16
 } else if a < 0.0 {
 0u16
 } else {
 (a * 256.0 + 0.5).floor() as u16
 }
}

fn curve_from_gamma(gamma: f32) -> Box<curveType> {
 Box::new(curveType::Curve(vec![float_to_u8Fixed8Number(gamma)]))
}

fn identity_curve() -> Box<curveType> {
 Box::new(curveType::Curve(Vec::new()))
}

/* from lcms: cmsWhitePointFromTemp */
/* tempK must be >= 4000. and <= 25000.
* Invalid values of tempK will return
* (x,y,Y) = (-1.0, -1.0, -1.0)
* similar to argyll: icx_DTEMP2XYZ() */
fn white_point_from_temp(temp_K: i32) -> qcms_CIE_xyY {
 let mut white_point: qcms_CIE_xyY = qcms_CIE_xyY {
 x: 0.,
 y: 0.,
 Y: 0.,
 };
 // No optimization provided.
 let T = temp_K as f64; // Square
 let T2 = T * T; // Cube
 let T3 = T2 * T;
 // For correlated color temperature (T) between 4000K and 7000K:
 let x = if (4000.0..=7000.0).contains(&T) {
 -4.6070 * (1E9 / T3) + 2.9678 * (1E6 / T2) + 0.09911 * (1E3 / T) + 0.244063
 } else if T > 7000.0 && T <= 25000.0 {
 -2.0064 * (1E9 / T3) + 1.9018 * (1E6 / T2) + 0.24748 * (1E3 / T) + 0.237040
 } else {
 // or for correlated color temperature (T) between 7000K and 25000K:
 // Invalid tempK
 white_point.x = -1.0;
 white_point.y = -1.0;
 white_point.Y = -1.0;
 debug_assert!(false, "invalid temp");
 return white_point;
 };
 // Obtain y(x)
 let y = -3.000 * (x * x) + 2.870 * x - 0.275;
 // wave factors (not used, but here for futures extensions)
 // let M1 = (-1.3515 - 1.7703*x + 5.9114 *y)/(0.0241 + 0.2562*x - 0.7341*y);
 // let M2 = (0.0300 - 31.4424*x + 30.0717*y)/(0.0241 + 0.2562*x - 0.7341*y);
 // Fill white_point struct
 white_point.x = x;
 white_point.y = y;
 white_point.Y = 1.0;
 white_point
}
#[no_mangle]
pub extern "C" fn qcms_white_point_sRGB() -> qcms_CIE_xyY {
 white_point_from_temp(6504)
}

/// See [Rec. ITU-T H.273 (12/2016)](https://www.itu.int/rec/T-REC-H.273-201612-I/en) Table 2
/// Values 0, 3, 13–21, 23–255 are all reserved so all map to the same variant
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum ColourPrimaries {
 /// For future use by ITU-T | ISO/IEC
 Reserved,
 /// Rec. ITU-R BT.709-6 
 /// Rec. ITU-R BT.1361-0 conventional colour gamut system and extended colour gamut system (historical) 
 /// IEC 61966-2-1 sRGB or sYCC IEC 61966-2-4 
 /// Society of Motion Picture and Television Engineers (MPTE) RP 177 (1993) Annex B 
 Bt709 = 1,
 /// Unspecified 
 /// Image characteristics are unknown or are determined by the application.
 Unspecified = 2,
 /// Rec. ITU-R BT.470-6 System M (historical) 
 /// United States National Television System Committee 1953 Recommendation for transmission standards for color television 
 /// United States Federal Communications Commission (2003) Title 47 Code of Federal Regulations 73.682 (a) (20) 
 Bt470M = 4,
 /// Rec. ITU-R BT.470-6 System B, G (historical) Rec. ITU-R BT.601-7 625 
 /// Rec. ITU-R BT.1358-0 625 (historical) 
 /// Rec. ITU-R BT.1700-0 625 PAL and 625 SECAM 
 Bt470Bg = 5,
 /// Rec. ITU-R BT.601-7 525 
 /// Rec. ITU-R BT.1358-1 525 or 625 (historical) Rec. ITU-R BT.1700-0 NTSC 
 /// SMPTE 170M (2004) 
 /// (functionally the same as the value 7) 
 Bt601 = 6,
 /// SMPTE 240M (1999) (historical) (functionally the same as the value 6) 
 Smpte240 = 7,
 /// Generic film (colour filters using Illuminant C) 
 Generic_film = 8,
 /// Rec. ITU-R BT.2020-2 
 /// Rec. ITU-R BT.2100-0 
 Bt2020 = 9,
 /// SMPTE ST 428-1 
 /// (CIE 1931 XYZ as in ISO 11664-1) 
 Xyz = 10,
 /// SMPTE RP 431-2 (2011) 
 Smpte431 = 11,
 /// SMPTE EG 432-1 (2010) 
 Smpte432 = 12,
 /// EBU Tech. 3213-E (1975) 
 Ebu3213 = 22,
}

impl From<u8> for ColourPrimaries {
 fn from(value: u8) -> Self {
 match value {
 0 | 3 | 13..=21 | 23..=255 => Self::Reserved,
 1 => Self::Bt709,
 2 => Self::Unspecified,
 4 => Self::Bt470M,
 5 => Self::Bt470Bg,
 6 => Self::Bt601,
 7 => Self::Smpte240,
 8 => Self::Generic_film,
 9 => Self::Bt2020,
 10 => Self::Xyz,
 11 => Self::Smpte431,
 12 => Self::Smpte432,
 22 => Self::Ebu3213,
 }
 }
}

#[test]
fn colour_primaries() {
 for value in 0..=u8::MAX {
 match ColourPrimaries::from(value) {
 ColourPrimaries::Reserved => {}
 variant => assert_eq!(value, variant as u8),
 }
 }
}

impl From<ColourPrimaries> for qcms_CIE_xyYTRIPLE {
 fn from(value: ColourPrimaries) -> Self {
 let red;
 let green;
 let blue;

 match value {
 ColourPrimaries::Reserved => panic!("CP={} is reserved", value as u8),
 ColourPrimaries::Bt709 => {
 green = qcms_chromaticity { x: 0.300, y: 0.600 };
 blue = qcms_chromaticity { x: 0.150, y: 0.060 };
 red = qcms_chromaticity { x: 0.640, y: 0.330 };
 }
 ColourPrimaries::Unspecified => panic!("CP={} is unspecified", value as u8),
 ColourPrimaries::Bt470M => {
 green = qcms_chromaticity { x: 0.21, y: 0.71 };
 blue = qcms_chromaticity { x: 0.14, y: 0.08 };
 red = qcms_chromaticity { x: 0.67, y: 0.33 };
 }
 ColourPrimaries::Bt470Bg => {
 green = qcms_chromaticity { x: 0.29, y: 0.60 };
 blue = qcms_chromaticity { x: 0.15, y: 0.06 };
 red = qcms_chromaticity { x: 0.64, y: 0.33 };
 }
 ColourPrimaries::Bt601 | ColourPrimaries::Smpte240 => {
 green = qcms_chromaticity { x: 0.310, y: 0.595 };
 blue = qcms_chromaticity { x: 0.155, y: 0.070 };
 red = qcms_chromaticity { x: 0.630, y: 0.340 };
 }
 ColourPrimaries::Generic_film => {
 green = qcms_chromaticity { x: 0.243, y: 0.692 };
 blue = qcms_chromaticity { x: 0.145, y: 0.049 };
 red = qcms_chromaticity { x: 0.681, y: 0.319 };
 }
 ColourPrimaries::Bt2020 => {
 green = qcms_chromaticity { x: 0.170, y: 0.797 };
 blue = qcms_chromaticity { x: 0.131, y: 0.046 };
 red = qcms_chromaticity { x: 0.708, y: 0.292 };
 }
 ColourPrimaries::Xyz => {
 green = qcms_chromaticity { x: 0.0, y: 1.0 };
 blue = qcms_chromaticity { x: 0.0, y: 0.0 };
 red = qcms_chromaticity { x: 1.0, y: 0.0 };
 }
 // These two share primaries, but have distinct white points
 ColourPrimaries::Smpte431 | ColourPrimaries::Smpte432 => {
 green = qcms_chromaticity { x: 0.265, y: 0.690 };
 blue = qcms_chromaticity { x: 0.150, y: 0.060 };
 red = qcms_chromaticity { x: 0.680, y: 0.320 };
 }
 ColourPrimaries::Ebu3213 => {
 green = qcms_chromaticity { x: 0.295, y: 0.605 };
 blue = qcms_chromaticity { x: 0.155, y: 0.077 };
 red = qcms_chromaticity { x: 0.630, y: 0.340 };
 }
 }

 Self {
 red: red.into(),
 green: green.into(),
 blue: blue.into(),
 }
 }
}

impl ColourPrimaries {
 fn white_point(self) -> qcms_CIE_xyY {
 match self {
 Self::Reserved => panic!("CP={} is reserved", self as u8),
 Self::Bt709
 | Self::Bt470Bg
 | Self::Bt601
 | Self::Smpte240
 | Self::Bt2020
 | Self::Smpte432
 | Self::Ebu3213 => qcms_chromaticity::D65,
 Self::Unspecified => panic!("CP={} is unspecified", self as u8),
 Self::Bt470M => qcms_chromaticity { x: 0.310, y: 0.316 },
 Self::Generic_film => qcms_chromaticity { x: 0.310, y: 0.316 },
 Self::Xyz => qcms_chromaticity {
 x: 1. / 3.,
 y: 1. / 3.,
 },
 Self::Smpte431 => qcms_chromaticity { x: 0.314, y: 0.351 },
 }
 .into()
 }

 fn is_usable(self) -> bool {
 match self {
 Self::Reserved | Self::Unspecified => false,
 _ => true
 }
 }
}

/// See [Rec. ITU-T H.273 (12/2016)](https://www.itu.int/rec/T-REC-H.273-201612-I/en) Table 3
/// Values 0, 3, 19–255 are all reserved so all map to the same variant
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum TransferCharacteristics {
 /// For future use by ITU-T | ISO/IEC
 Reserved,
 /// Rec. ITU-R BT.709-6 
 /// Rec. ITU-R BT.1361-0 conventional colour gamut system (historical) 
 /// (functionally the same as the values 6, 14 and 15) 
 Bt709 = 1,
 /// Image characteristics are unknown or are determined by the application. 
 Unspecified = 2,
 /// Rec. ITU-R BT.470-6 System M (historical) 
 /// United States National Television System Committee 1953 Recommendation for transmission standards for color television 
 /// United States Federal Communications Commission (2003) Title 47 Code of Federal Regulations 73.682 (a) (20) 
 /// Rec. ITU-R BT.1700-0 625 PAL and 625 SECAM 
 Bt470M = 4,
 /// Rec. ITU-R BT.470-6 System B, G (historical) 
 Bt470Bg = 5,
 /// Rec. ITU-R BT.601-7 525 or 625 
 /// Rec. ITU-R BT.1358-1 525 or 625 (historical) 
 /// Rec. ITU-R BT.1700-0 NTSC SMPTE 170M (2004) 
 /// (functionally the same as the values 1, 14 and 15) 
 Bt601 = 6,
 /// SMPTE 240M (1999) (historical) 
 Smpte240 = 7,
 /// Linear transfer characteristics 
 Linear = 8,
 /// Logarithmic transfer characteristic (100:1 range) 
 Log_100 = 9,
 /// Logarithmic transfer characteristic (100 * Sqrt( 10 ) : 1 range) 
 Log_100_sqrt10 = 10,
 /// IEC 61966-2-4 
 Iec61966 = 11,
 /// Rec. ITU-R BT.1361-0 extended colour gamut system (historical) 
 Bt_1361 = 12,
 /// IEC 61966-2-1 sRGB or sYCC 
 Srgb = 13,
 /// Rec. ITU-R BT.2020-2 (10-bit system) 
 /// (functionally the same as the values 1, 6 and 15) 
 Bt2020_10bit = 14,
 /// Rec. ITU-R BT.2020-2 (12-bit system) 
 /// (functionally the same as the values 1, 6 and 14) 
 Bt2020_12bit = 15,
 /// SMPTE ST 2084 for 10-, 12-, 14- and 16-bitsystems 
 /// Rec. ITU-R BT.2100-0 perceptual quantization (PQ) system 
 Smpte2084 = 16,
 /// SMPTE ST 428-1 
 Smpte428 = 17,
 /// ARIB STD-B67 
 /// Rec. ITU-R BT.2100-0 hybrid log- gamma (HLG) system 
 Hlg = 18,
}

#[test]
fn transfer_characteristics() {
 for value in 0..=u8::MAX {
 match TransferCharacteristics::from(value) {
 TransferCharacteristics::Reserved => {}
 variant => assert_eq!(value, variant as u8),
 }
 }
}

impl From<u8> for TransferCharacteristics {
 fn from(value: u8) -> Self {
 match value {
 0 | 3 | 19..=255 => Self::Reserved,
 1 => Self::Bt709,
 2 => Self::Unspecified,
 4 => Self::Bt470M,
 5 => Self::Bt470Bg,
 6 => Self::Bt601,
 7 => Self::Smpte240, // unimplemented
 8 => Self::Linear,
 9 => Self::Log_100,
 10 => Self::Log_100_sqrt10,
 11 => Self::Iec61966, // unimplemented
 12 => Self::Bt_1361, // unimplemented
 13 => Self::Srgb,
 14 => Self::Bt2020_10bit,
 15 => Self::Bt2020_12bit,
 16 => Self::Smpte2084,
 17 => Self::Smpte428, // unimplemented
 18 => Self::Hlg,
 }
 }
}

impl TryFrom<TransferCharacteristics> for curveType {
 type Error = ();
 /// See [ICC.1:2010](https://www.color.org/specification/ICC1v43_2010-12.pdf)
 /// See [Rec. ITU-R BT.2100-2](https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.2100-2-201807-I!!PDF-E.pdf)
 fn try_from(value: TransferCharacteristics) -> Result<Self, Self::Error> {
 const NUM_TRC_TABLE_ENTRIES: i32 = 1024;

 Ok(match value {
 TransferCharacteristics::Reserved => panic!("TC={} is reserved", value as u8),
 TransferCharacteristics::Bt709
 | TransferCharacteristics::Bt601
 | TransferCharacteristics::Bt2020_10bit
 | TransferCharacteristics::Bt2020_12bit => {
 // The opto-electronic transfer characteristic function (OETF)
 // as defined in ITU-T H.273 table 3, row 1:
 //
 // V = (α * Lc^0.45) − (α − 1) for 1 >= Lc >= β
 // V = 4.500 * Lc for β > Lc >= 0
 //
 // Inverting gives the electro-optical transfer characteristic
 // function (EOTF) which can be represented as ICC
 // parametricCurveType with 4 parameters (ICC.1:2010 Table 5).
 // Converting between the two (Lc ↔︎ Y, V ↔︎ X):
 //
 // Y = (a * X + b)^g for (X >= d)
 // Y = c * X for (X < d)
 //
 // g, a, b, c, d can then be defined in terms of α and β:
 //
 // g = 1 / 0.45
 // a = 1 / α
 // b = 1 - α
 // c = 1 / 4.500
 // d = 4.500 * β
 //
 // α and β are determined by solving the piecewise equations to
 // ensure continuity of both value and slope at the value β.
 // We use the values specified for 10-bit systems in
 // https://www.itu.int/rec/R-REC-BT.2020-2-201510-I Table 4
 // since this results in the similar values as available ICC
 // profiles after converting to s15Fixed16Number, providing us
 // good test coverage.

 type Float = f32;

 const alpha: Float = 1.099;
 const beta: Float = 0.018;

 const linear_coef: Float = 4.500;
 const pow_exp: Float = 0.45;

 const g: Float = 1. / pow_exp;
 const a: Float = 1. / alpha;
 const b: Float = 1. - a;
 const c: Float = 1. / linear_coef;
 const d: Float = linear_coef * beta;

 curveType::Parametric(vec![g, a, b, c, d])
 }
 TransferCharacteristics::Unspecified => panic!("TC={} is unspecified", value as u8),
 TransferCharacteristics::Bt470M => *curve_from_gamma(2.2),
 TransferCharacteristics::Bt470Bg => *curve_from_gamma(2.8),
 TransferCharacteristics::Smpte240 => return Err(()),
 TransferCharacteristics::Linear => *curve_from_gamma(1.),
 TransferCharacteristics::Log_100 => {
 // See log_100_transfer_characteristics() for derivation
 // The opto-electronic transfer characteristic function (OETF)
 // as defined in ITU-T H.273 table 3, row 9:
 //
 // V = 1.0 + Log10(Lc) ÷ 2 for 1 >= Lc >= 0.01
 // V = 0.0 for 0.01 > Lc >= 0
 //
 // Inverting this to give the EOTF required for the profile gives
 //
 // Lc = 10^(2*V - 2) for 1 >= V >= 0
 let table = build_trc_table(NUM_TRC_TABLE_ENTRIES, |v| 10f64.powf(2. * v - 2.));
 curveType::Curve(table)
 }
 TransferCharacteristics::Log_100_sqrt10 => {
 // The opto-electronic transfer characteristic function (OETF)
 // as defined in ITU-T H.273 table 3, row 10:
 //
 // V = 1.0 + Log10(Lc) ÷ 2.5 for 1 >= Lc >= Sqrt(10) ÷ 1000
 // V = 0.0 for Sqrt(10) ÷ 1000 > Lc >= 0
 //
 // Inverting this to give the EOTF required for the profile gives
 //
 // Lc = 10^(2.5*V - 2.5) for 1 >= V >= 0
 let table = build_trc_table(NUM_TRC_TABLE_ENTRIES, |v| 10f64.powf(2.5 * v - 2.5));
 curveType::Curve(table)
 }
 TransferCharacteristics::Iec61966 => return Err(()),
 TransferCharacteristics::Bt_1361 => return Err(()),
 TransferCharacteristics::Srgb => {
 // Should we prefer this or curveType::Parametric?
 curveType::Curve(build_sRGB_gamma_table(NUM_TRC_TABLE_ENTRIES))
 }

 TransferCharacteristics::Smpte2084 => {
 // Despite using Lo rather than Lc, H.273 gives the OETF:
 //
 // V = ( ( c1 + c2 * (Lo)^n ) ÷ ( 1 + c3 * (Lo)^n ) )^m
 const c1: f64 = 0.8359375;
 const c2: f64 = 18.8515625;
 const c3: f64 = 18.6875;
 const m: f64 = 78.84375;
 const n: f64 = 0.1593017578125;

 // Inverting this to give the EOTF required for the profile
 // (and confirmed by Rec. ITU-R BT.2100-2, Table 4) gives
 //
 // Y = ( max[( X^(1/m) - c1 ), 0] ÷ ( c2 - c3 * X^(1/m) ) )^(1/n)
 let table = build_trc_table(NUM_TRC_TABLE_ENTRIES, |x| {
 ((x.powf(1. / m) - c1).max(0.) / (c2 - c3 * x.powf(1. / m))).powf(1. / n)
 });
 curveType::Curve(table)
 }
 TransferCharacteristics::Smpte428 => return Err(()),
 TransferCharacteristics::Hlg => {
 // The opto-electronic transfer characteristic function (OETF)
 // as defined in ITU-T H.273 table 3, row 18:
 //
 // V = a * Ln(12 * Lc - b) + c for 1 >= Lc > 1 ÷ 12
 // V = Sqrt(3) * Lc^0.5 for 1 ÷ 12 >= Lc >= 0
 const a: f64 = 0.17883277;
 const b: f64 = 0.28466892;
 const c: f64 = 0.55991073;

 // Inverting this to give the EOTF required for the profile
 // (and confirmed by Rec. ITU-R BT.2100-2, Table 4) gives
 //
 // Y = (X^2) / 3 for 0 <= X <= 0.5
 // Y = ((e^((X-c)/a))+b)/12 for 0.5 < X <= 1
 let table = build_trc_table(NUM_TRC_TABLE_ENTRIES, |x| {
 if x <= 0.5 {
 let y1 = x.powf(2.) / 3.;
 assert!((0. ..=1. / 12.).contains(&y1));
 y1
 } else {
 (std::f64::consts::E.powf((x - c) / a) + b) / 12.
 }
 });
 curveType::Curve(table)
 }
 })
 }
}

impl TransferCharacteristics {
 fn is_usable(self) -> bool {
 match self {
 Self::Reserved | Self::Unspecified => false,
 _ => true
 }
 }
}

#[cfg(test)]
fn check_transfer_characteristics(cicp: TransferCharacteristics, icc_path: &str) {
 let mut cicp_out = [0u8; crate::transform::PRECACHE_OUTPUT_SIZE];
 let mut icc_out = [0u8; crate::transform::PRECACHE_OUTPUT_SIZE];
 let cicp_tc = curveType::try_from(cicp).unwrap();
 let icc = Profile::new_from_path(icc_path).unwrap();
 let icc_tc = icc.redTRC.as_ref().unwrap();

 eprintln!("cicp_tc: {:?}", cicp_tc);
 eprintln!("icc_tc: {:?}", icc_tc);

 crate::transform_util::compute_precache(icc_tc, &mut icc_out);
 crate::transform_util::compute_precache(&cicp_tc, &mut cicp_out);

 let mut off_by_one = 0;
 for i in 0..cicp_out.len() {
 match (cicp_out[i] as i16) - (icc_out[i] as i16) {
 0 => {}
 1 | -1 => {
 off_by_one += 1;
 }
 _ => assert_eq!(cicp_out[i], icc_out[i], "difference at index {}", i),
 }
 }
 eprintln!("{} / {} off by one", off_by_one, cicp_out.len());
}

#[test]
fn srgb_transfer_characteristics() {
 check_transfer_characteristics(TransferCharacteristics::Srgb, "sRGB_lcms.icc");
}

#[test]
fn bt709_transfer_characteristics() {
 check_transfer_characteristics(TransferCharacteristics::Bt709, "ITU-709.icc");
}

#[test]
fn bt2020_10bit_transfer_characteristics() {
 check_transfer_characteristics(TransferCharacteristics::Bt2020_10bit, "ITU-2020.icc");
}

#[test]
fn bt2020_12bit_transfer_characteristics() {
 check_transfer_characteristics(TransferCharacteristics::Bt2020_12bit, "ITU-2020.icc");
}

impl Profile {
 //XXX: it would be nice if we had a way of ensuring
 // everything in a profile was initialized regardless of how it was created
 //XXX: should this also be taking a black_point?
 /* similar to CGColorSpaceCreateCalibratedRGB */
 pub fn new_rgb_with_table(
 white_point: qcms_CIE_xyY,
 primaries: qcms_CIE_xyYTRIPLE,
 table: &[u16],
 ) -> Option<Box<Profile>> {
 let mut profile = profile_create();
 //XXX: should store the whitepoint
 if !set_rgb_colorants(&mut profile, white_point, primaries) {
 return None;
 }
 profile.redTRC = Some(curve_from_table(table));
 profile.blueTRC = Some(curve_from_table(table));
 profile.greenTRC = Some(curve_from_table(table));
 profile.class_type = DISPLAY_DEVICE_PROFILE;
 profile.rendering_intent = Perceptual;
 profile.color_space = RGB_SIGNATURE;
 profile.pcs = XYZ_TYPE;
 Some(profile)
 }
 pub fn new_sRGB() -> Box<Profile> {
 let D65 = qcms_white_point_sRGB();
 let table = build_sRGB_gamma_table(1024);

 let mut srgb = Profile::new_rgb_with_table(
 D65,
 qcms_CIE_xyYTRIPLE::from(ColourPrimaries::Bt709),
 &table,
 )
 .unwrap();
 srgb.is_srgb = true;
 srgb
 }

 /// Returns true if this profile is sRGB
 pub fn is_sRGB(&self) -> bool {
 self.is_srgb
 }

 pub(crate) fn new_sRGB_parametric() -> Box<Profile> {
 let primaries = qcms_CIE_xyYTRIPLE::from(ColourPrimaries::Bt709);
 let white_point = qcms_white_point_sRGB();
 let mut profile = profile_create();
 set_rgb_colorants(&mut profile, white_point, primaries);

 let curve = Box::new(curveType::Parametric(vec![
 2.4,
 1. / 1.055,
 0.055 / 1.055,
 1. / 12.92,
 0.04045,
 ]));
 profile.redTRC = Some(curve.clone());
 profile.blueTRC = Some(curve.clone());
 profile.greenTRC = Some(curve);
 profile.class_type = DISPLAY_DEVICE_PROFILE;
 profile.rendering_intent = Perceptual;
 profile.color_space = RGB_SIGNATURE;
 profile.pcs = XYZ_TYPE;
 profile.is_srgb = true;
 profile
 }

 pub(crate) fn new_displayP3() -> Box<Profile> {
 let primaries = qcms_CIE_xyYTRIPLE::from(ColourPrimaries::Smpte432);
 let white_point = qcms_white_point_sRGB();
 let mut profile = profile_create();
 set_rgb_colorants(&mut profile, white_point, primaries);

 let curve = Box::new(curveType::Parametric(vec![
 2.4,
 1. / 1.055,
 0.055 / 1.055,
 1. / 12.92,
 0.04045,
 ]));
 profile.redTRC = Some(curve.clone());
 profile.blueTRC = Some(curve.clone());
 profile.greenTRC = Some(curve);
 profile.class_type = DISPLAY_DEVICE_PROFILE;
 profile.rendering_intent = Perceptual;
 profile.color_space = RGB_SIGNATURE;
 profile.pcs = XYZ_TYPE;
 profile.is_srgb = false;
 profile
 }

 /// Create a new profile with D50 adopted white and identity transform functions
 pub fn new_XYZD50() -> Box<Profile> {
 let mut profile = profile_create();
 profile.redColorant.X = double_to_s15Fixed16Number(1.);
 profile.redColorant.Y = double_to_s15Fixed16Number(0.);
 profile.redColorant.Z = double_to_s15Fixed16Number(0.);
 profile.greenColorant.X = double_to_s15Fixed16Number(0.);
 profile.greenColorant.Y = double_to_s15Fixed16Number(1.);
 profile.greenColorant.Z = double_to_s15Fixed16Number(0.);
 profile.blueColorant.X = double_to_s15Fixed16Number(0.);
 profile.blueColorant.Y = double_to_s15Fixed16Number(0.);
 profile.blueColorant.Z = double_to_s15Fixed16Number(1.);
 profile.redTRC = Some(identity_curve());
 profile.blueTRC = Some(identity_curve());
 profile.greenTRC = Some(identity_curve());

 profile.class_type = DISPLAY_DEVICE_PROFILE;
 profile.rendering_intent = Perceptual;
 profile.color_space = RGB_SIGNATURE;
 profile.pcs = XYZ_TYPE;
 profile
 }

 pub fn new_cicp(cp: ColourPrimaries, tc: TransferCharacteristics) -> Option<Box<Profile>> {
 let mut profile = profile_create();
 if !cp.is_usable() || !tc.is_usable() {
 return None;
 }
 //XXX: should store the whitepoint
 if !set_rgb_colorants(&mut profile, cp.white_point(), qcms_CIE_xyYTRIPLE::from(cp)) {
 return None;
 }
 let curve = curveType::try_from(tc).ok()?;
 profile.redTRC = Some(Box::new(curve.clone()));
 profile.blueTRC = Some(Box::new(curve.clone()));
 profile.greenTRC = Some(Box::new(curve));
 profile.class_type = DISPLAY_DEVICE_PROFILE;
 profile.rendering_intent = Perceptual;
 profile.color_space = RGB_SIGNATURE;
 profile.pcs = XYZ_TYPE;

 profile.is_srgb = (cp, tc) == (ColourPrimaries::Bt709, TransferCharacteristics::Srgb);
 Some(profile)
 }

 pub fn new_gray_with_gamma(gamma: f32) -> Box<Profile> {
 let mut profile = profile_create();

 profile.grayTRC = Some(curve_from_gamma(gamma));
 profile.class_type = DISPLAY_DEVICE_PROFILE;
 profile.rendering_intent = Perceptual;
 profile.color_space = GRAY_SIGNATURE;
 profile.pcs = XYZ_TYPE;
 profile
 }

 pub fn new_rgb_with_gamma_set(
 white_point: qcms_CIE_xyY,
 primaries: qcms_CIE_xyYTRIPLE,
 redGamma: f32,
 greenGamma: f32,
 blueGamma: f32,
 ) -> Option<Box<Profile>> {
 let mut profile = profile_create();

 //XXX: should store the whitepoint
 if !set_rgb_colorants(&mut profile, white_point, primaries) {
 return None;
 }
 profile.redTRC = Some(curve_from_gamma(redGamma));
 profile.blueTRC = Some(curve_from_gamma(blueGamma));
 profile.greenTRC = Some(curve_from_gamma(greenGamma));
 profile.class_type = DISPLAY_DEVICE_PROFILE;
 profile.rendering_intent = Perceptual;
 profile.color_space = RGB_SIGNATURE;
 profile.pcs = XYZ_TYPE;
 Some(profile)
 }

 pub fn new_from_path(file: &str) -> Option<Box<Profile>> {
 Profile::new_from_slice(&std::fs::read(file).ok()?, false)
 }

 pub fn new_from_slice(mem: &[u8], curves_only: bool) -> Option<Box<Profile>> {
 let length: u32;
 let mut source: MemSource = MemSource {
 buf: mem,
 valid: false,
 invalid_reason: None,
 };
 let index;
 source.valid = true;
 let src: &mut MemSource = &mut source;
 if mem.len() < 4 {
 return None;
 }
 length = read_u32(src, 0);
 if length as usize <= mem.len() {
 // shrink the area that we can read if appropriate
 src.buf = &src.buf[0..length as usize];
 } else {
 return None;
 }
 /* ensure that the profile size is sane so it's easier to reason about */
 if src.buf.len() <= 64 || src.buf.len() >= MAX_PROFILE_SIZE {
 return None;
 }
 let mut profile = profile_create();

 check_CMM_type_signature(src);
 check_profile_version(src);
 read_class_signature(&mut profile, src);
 read_rendering_intent(&mut profile, src);
 read_color_space(&mut profile, src);
 read_pcs(&mut profile, src);
 //TODO read rest of profile stuff
 if !src.valid {
 return None;
 }

 index = read_tag_table(&mut profile, src);
 if !src.valid || index.is_empty() {
 return None;
 }

 if let Some(chad) = find_tag(&index, TAG_CHAD) {
 profile.chromaticAdaption = Some(read_tag_s15Fixed16ArrayType(src, chad))
 } else {
 profile.chromaticAdaption = None; //Signal the data is not present
 }

 if profile.class_type == DISPLAY_DEVICE_PROFILE
 || profile.class_type == INPUT_DEVICE_PROFILE
 || profile.class_type == OUTPUT_DEVICE_PROFILE
 || profile.class_type == COLOR_SPACE_PROFILE
 {
 if profile.color_space == RGB_SIGNATURE {
 if !curves_only {
 if let Some(A2B0) = find_tag(&index, TAG_A2B0) {
 let lut_type = read_u32(src, A2B0.offset as usize);
 if lut_type == LUT8_TYPE || lut_type == LUT16_TYPE {
 profile.A2B0 = read_tag_lutType(src, A2B0)
 } else if lut_type == LUT_MAB_TYPE {
 profile.mAB = read_tag_lutmABType(src, A2B0)
 }
 }
 if let Some(B2A0) = find_tag(&index, TAG_B2A0) {
 let lut_type = read_u32(src, B2A0.offset as usize);
 if lut_type == LUT8_TYPE || lut_type == LUT16_TYPE {
 profile.B2A0 = read_tag_lutType(src, B2A0)
 } else if lut_type == LUT_MBA_TYPE {
 profile.mBA = read_tag_lutmABType(src, B2A0)
 }
 }
 }
 if find_tag(&index, TAG_rXYZ).is_some() || curves_only {
 profile.redColorant = read_tag_XYZType(src, &index, TAG_rXYZ);
 profile.greenColorant = read_tag_XYZType(src, &index, TAG_gXYZ);
 profile.blueColorant = read_tag_XYZType(src, &index, TAG_bXYZ)
 }
 if !src.valid {
 return None;
 }

 if find_tag(&index, TAG_rTRC).is_some() || curves_only {
 profile.redTRC = read_tag_curveType(src, &index, TAG_rTRC);
 profile.greenTRC = read_tag_curveType(src, &index, TAG_gTRC);
 profile.blueTRC = read_tag_curveType(src, &index, TAG_bTRC);
 if profile.redTRC.is_none()
 || profile.blueTRC.is_none()
 || profile.greenTRC.is_none()
 {
 return None;
 }
 }
 } else if profile.color_space == GRAY_SIGNATURE {
 profile.grayTRC = read_tag_curveType(src, &index, TAG_kTRC);
 profile.grayTRC.as_ref()?;
 } else if profile.color_space == CMYK_SIGNATURE {
 if let Some(A2B0) = find_tag(&index, TAG_A2B0) {
 let lut_type = read_u32(src, A2B0.offset as usize);
 if lut_type == LUT8_TYPE || lut_type == LUT16_TYPE {
 profile.A2B0 = read_tag_lutType(src, A2B0)
 } else if lut_type == LUT_MBA_TYPE {
 profile.mAB = read_tag_lutmABType(src, A2B0)
 }
 }
 } else {
 debug_assert!(false, "read_color_space protects against entering here");
 return None;
 }
 } else {
 return None;
 }

 if !src.valid {
 return None;
 }
 Some(profile)
 }
 /// Precomputes the information needed for this profile to be
 /// used as the output profile when constructing a `Transform`.
 pub fn precache_output_transform(&mut self) {
 crate::transform::qcms_profile_precache_output_transform(self);
 }
}

Quelle iccread.rs Sprache: unbekannt

[ Dauer der Verarbeitung: 0.51 Sekunden (vorverarbeitet) ]