1 /*
2 * Copyright 2022 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef ULTRAHDR_ICC_H
18 #define ULTRAHDR_ICC_H
19
20 #include <memory>
21
22 #ifndef USE_BIG_ENDIAN_IN_ICC
23 #define USE_BIG_ENDIAN_IN_ICC true
24 #endif
25
26 #undef Endian_SwapBE32
27 #undef Endian_SwapBE16
28 #if USE_BIG_ENDIAN_IN_ICC
29 #define Endian_SwapBE32(n) EndianSwap32(n)
30 #define Endian_SwapBE16(n) EndianSwap16(n)
31 #else
32 #define Endian_SwapBE32(n) (n)
33 #define Endian_SwapBE16(n) (n)
34 #endif
35
36 #include "ultrahdr/jpegr.h"
37 #include "ultrahdr/gainmapmath.h"
38 #include "ultrahdr/jpegrutils.h"
39
40 namespace ultrahdr {
41
42 typedef int32_t Fixed;
43 #define Fixed1 (1 << 16)
44 #define MaxS32FitsInFloat 2147483520
45 #define MinS32FitsInFloat (-MaxS32FitsInFloat)
46 #define FixedToFloat(x) ((x)*1.52587890625e-5f)
47
48 typedef struct Matrix3x3 {
49 float vals[3][3];
50 } Matrix3x3;
51
52 // A transfer function mapping encoded values to linear values,
53 // represented by this 7-parameter piecewise function:
54 //
55 // linear = sign(encoded) * (c*|encoded| + f) , 0 <= |encoded| < d
56 // = sign(encoded) * ((a*|encoded| + b)^g + e), d <= |encoded|
57 //
58 // (A simple gamma transfer function sets g to gamma and a to 1.)
59 typedef struct TransferFunction {
60 float g, a, b, c, d, e, f;
61 } TransferFunction;
62
63 static constexpr TransferFunction kSRGB_TransFun = {
64 2.4f, (float)(1 / 1.055), (float)(0.055 / 1.055), (float)(1 / 12.92), 0.04045f, 0.0f, 0.0f};
65
66 static constexpr TransferFunction kLinear_TransFun = {1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f};
67
68 // The D50 illuminant.
69 constexpr float kD50_x = 0.9642f;
70 constexpr float kD50_y = 1.0000f;
71 constexpr float kD50_z = 0.8249f;
72
73 enum {
74 // data_color_space
75 Signature_CMYK = 0x434D594B,
76 Signature_Gray = 0x47524159,
77 Signature_RGB = 0x52474220,
78
79 // pcs
80 Signature_Lab = 0x4C616220,
81 Signature_XYZ = 0x58595A20,
82 };
83
84 typedef uint32_t FourByteTag;
SetFourByteTag(char a,char b,char c,char d)85 static inline constexpr FourByteTag SetFourByteTag(char a, char b, char c, char d) {
86 return (((uint32_t)a << 24) | ((uint32_t)b << 16) | ((uint32_t)c << 8) | (uint32_t)d);
87 }
88
89 static constexpr char kICCIdentifier[] = "ICC_PROFILE";
90 // 12 for the actual identifier, +2 for the chunk count and chunk index which
91 // will always follow.
92 static constexpr size_t kICCIdentifierSize = 14;
93
94 // This is equal to the header size according to the ICC specification (128)
95 // plus the size of the tag count (4). We include the tag count since we
96 // always require it to be present anyway.
97 static constexpr size_t kICCHeaderSize = 132;
98
99 // Contains a signature (4), offset (4), and size (4).
100 static constexpr size_t kICCTagTableEntrySize = 12;
101
102 // size should be 20; 4 bytes for type descriptor, 4 bytes reserved, 12
103 // bytes for a single XYZ number type (4 bytes per coordinate).
104 static constexpr size_t kColorantTagSize = 20;
105
106 static constexpr uint32_t kDisplay_Profile = SetFourByteTag('m', 'n', 't', 'r');
107 static constexpr uint32_t kRGB_ColorSpace = SetFourByteTag('R', 'G', 'B', ' ');
108 static constexpr uint32_t kXYZ_PCSSpace = SetFourByteTag('X', 'Y', 'Z', ' ');
109 static constexpr uint32_t kACSP_Signature = SetFourByteTag('a', 'c', 's', 'p');
110
111 static constexpr uint32_t kTAG_desc = SetFourByteTag('d', 'e', 's', 'c');
112 static constexpr uint32_t kTAG_TextType = SetFourByteTag('m', 'l', 'u', 'c');
113 static constexpr uint32_t kTAG_rXYZ = SetFourByteTag('r', 'X', 'Y', 'Z');
114 static constexpr uint32_t kTAG_gXYZ = SetFourByteTag('g', 'X', 'Y', 'Z');
115 static constexpr uint32_t kTAG_bXYZ = SetFourByteTag('b', 'X', 'Y', 'Z');
116 static constexpr uint32_t kTAG_wtpt = SetFourByteTag('w', 't', 'p', 't');
117 static constexpr uint32_t kTAG_rTRC = SetFourByteTag('r', 'T', 'R', 'C');
118 static constexpr uint32_t kTAG_gTRC = SetFourByteTag('g', 'T', 'R', 'C');
119 static constexpr uint32_t kTAG_bTRC = SetFourByteTag('b', 'T', 'R', 'C');
120 static constexpr uint32_t kTAG_cicp = SetFourByteTag('c', 'i', 'c', 'p');
121 static constexpr uint32_t kTAG_cprt = SetFourByteTag('c', 'p', 'r', 't');
122 static constexpr uint32_t kTAG_A2B0 = SetFourByteTag('A', '2', 'B', '0');
123 static constexpr uint32_t kTAG_B2A0 = SetFourByteTag('B', '2', 'A', '0');
124
125 static constexpr uint32_t kTAG_CurveType = SetFourByteTag('c', 'u', 'r', 'v');
126 static constexpr uint32_t kTAG_mABType = SetFourByteTag('m', 'A', 'B', ' ');
127 static constexpr uint32_t kTAG_mBAType = SetFourByteTag('m', 'B', 'A', ' ');
128 static constexpr uint32_t kTAG_ParaCurveType = SetFourByteTag('p', 'a', 'r', 'a');
129
130 static constexpr Matrix3x3 kSRGB = {{
131 // ICC fixed-point (16.16) representation, taken from skcms. Please keep them exactly in sync.
132 // 0.436065674f, 0.385147095f, 0.143066406f,
133 // 0.222488403f, 0.716873169f, 0.060607910f,
134 // 0.013916016f, 0.097076416f, 0.714096069f,
135 {FixedToFloat(0x6FA2), FixedToFloat(0x6299), FixedToFloat(0x24A0)},
136 {FixedToFloat(0x38F5), FixedToFloat(0xB785), FixedToFloat(0x0F84)},
137 {FixedToFloat(0x0390), FixedToFloat(0x18DA), FixedToFloat(0xB6CF)},
138 }};
139
140 static constexpr Matrix3x3 kDisplayP3 = {{
141 {0.515102f, 0.291965f, 0.157153f},
142 {0.241182f, 0.692236f, 0.0665819f},
143 {-0.00104941f, 0.0418818f, 0.784378f},
144 }};
145
146 static constexpr Matrix3x3 kRec2020 = {{
147 {0.673459f, 0.165661f, 0.125100f},
148 {0.279033f, 0.675338f, 0.0456288f},
149 {-0.00193139f, 0.0299794f, 0.797162f},
150 }};
151
152 static constexpr uint32_t kCICPPrimariesSRGB = 1;
153 static constexpr uint32_t kCICPPrimariesP3 = 12;
154 static constexpr uint32_t kCICPPrimariesRec2020 = 9;
155
156 static constexpr uint32_t kCICPTrfnSRGB = 1;
157 static constexpr uint32_t kCICPTrfnLinear = 8;
158 static constexpr uint32_t kCICPTrfnPQ = 16;
159 static constexpr uint32_t kCICPTrfnHLG = 18;
160
161 enum ParaCurveType {
162 kExponential_ParaCurveType = 0,
163 kGAB_ParaCurveType = 1,
164 kGABC_ParaCurveType = 2,
165 kGABDE_ParaCurveType = 3,
166 kGABCDEF_ParaCurveType = 4,
167 };
168
169 /**
170 * Return the closest int for the given float. Returns MaxS32FitsInFloat for NaN.
171 */
float_saturate2int(float x)172 static inline int float_saturate2int(float x) {
173 x = x < MaxS32FitsInFloat ? x : MaxS32FitsInFloat;
174 x = x > MinS32FitsInFloat ? x : MinS32FitsInFloat;
175 return (int)x;
176 }
177
float_round_to_fixed(float x)178 static inline Fixed float_round_to_fixed(float x) {
179 return float_saturate2int((float)floor((double)x * Fixed1 + 0.5));
180 }
181
float_round_to_unorm16(float x)182 static inline uint16_t float_round_to_unorm16(float x) {
183 x = x * 65535.f + 0.5f;
184 if (x > 65535) return 65535;
185 if (x < 0) return 0;
186 return static_cast<uint16_t>(x);
187 }
188
float_to_table16(const float f,uint8_t * table_16)189 static inline void float_to_table16(const float f, uint8_t* table_16) {
190 *reinterpret_cast<uint16_t*>(table_16) = Endian_SwapBE16(float_round_to_unorm16(f));
191 }
192
isfinitef_(float x)193 static inline bool isfinitef_(float x) { return 0 == x * 0; }
194
195 struct ICCHeader {
196 // Size of the profile (computed)
197 uint32_t size;
198 // Preferred CMM type (ignored)
199 uint32_t cmm_type = 0;
200 // Version 4.3 or 4.4 if CICP is included.
201 uint32_t version = Endian_SwapBE32(0x04300000);
202 // Display device profile
203 uint32_t profile_class = Endian_SwapBE32(kDisplay_Profile);
204 // RGB input color space;
205 uint32_t data_color_space = Endian_SwapBE32(kRGB_ColorSpace);
206 // Profile connection space.
207 uint32_t pcs = Endian_SwapBE32(kXYZ_PCSSpace);
208 // Date and time (ignored)
209 uint8_t creation_date_time[12] = {0};
210 // Profile signature
211 uint32_t signature = Endian_SwapBE32(kACSP_Signature);
212 // Platform target (ignored)
213 uint32_t platform = 0;
214 // Flags: not embedded, can be used independently
215 uint32_t flags = 0x00000000;
216 // Device manufacturer (ignored)
217 uint32_t device_manufacturer = 0;
218 // Device model (ignored)
219 uint32_t device_model = 0;
220 // Device attributes (ignored)
221 uint8_t device_attributes[8] = {0};
222 // Relative colorimetric rendering intent
223 uint32_t rendering_intent = Endian_SwapBE32(1);
224 // D50 standard illuminant (X, Y, Z)
225 uint32_t illuminant_X = Endian_SwapBE32(float_round_to_fixed(kD50_x));
226 uint32_t illuminant_Y = Endian_SwapBE32(float_round_to_fixed(kD50_y));
227 uint32_t illuminant_Z = Endian_SwapBE32(float_round_to_fixed(kD50_z));
228 // Profile creator (ignored)
229 uint32_t creator = 0;
230 // Profile id checksum (ignored)
231 uint8_t profile_id[16] = {0};
232 // Reserved (ignored)
233 uint8_t reserved[28] = {0};
234 // Technically not part of header, but required
235 uint32_t tag_count = 0;
236 };
237
238 class IccHelper {
239 private:
240 static constexpr uint32_t kTrcTableSize = 65;
241 static constexpr uint32_t kGridSize = 17;
242 static constexpr size_t kNumChannels = 3;
243
244 static std::shared_ptr<DataStruct> write_text_tag(const char* text);
245 static std::string get_desc_string(const uhdr_color_transfer_t tf,
246 const uhdr_color_gamut_t gamut);
247 static std::shared_ptr<DataStruct> write_xyz_tag(float x, float y, float z);
248 static std::shared_ptr<DataStruct> write_trc_tag(const int table_entries, const void* table_16);
249 static std::shared_ptr<DataStruct> write_trc_tag(const TransferFunction& fn);
250 static float compute_tone_map_gain(const uhdr_color_transfer_t tf, float L);
251 static std::shared_ptr<DataStruct> write_cicp_tag(uint32_t color_primaries,
252 uint32_t transfer_characteristics);
253 static std::shared_ptr<DataStruct> write_mAB_or_mBA_tag(uint32_t type, bool has_a_curves,
254 const uint8_t* grid_points,
255 const uint8_t* grid_16);
256 static void compute_lut_entry(const Matrix3x3& src_to_XYZD50, float rgb[3]);
257 static std::shared_ptr<DataStruct> write_clut(const uint8_t* grid_points, const uint8_t* grid_16);
258
259 // Checks if a set of xyz tags is equivalent to a 3x3 Matrix. Each input
260 // tag buffer assumed to be at least kColorantTagSize in size.
261 static bool tagsEqualToMatrix(const Matrix3x3& matrix, const uint8_t* red_tag,
262 const uint8_t* green_tag, const uint8_t* blue_tag);
263
264 public:
265 // Output includes JPEG embedding identifier and chunk information, but not
266 // APPx information.
267 static std::shared_ptr<DataStruct> writeIccProfile(const uhdr_color_transfer_t tf,
268 const uhdr_color_gamut_t gamut);
269 // NOTE: this function is not robust; it can infer gamuts that IccHelper
270 // writes out but should not be considered a reference implementation for
271 // robust parsing of ICC profiles or their gamuts.
272 static uhdr_color_gamut_t readIccColorGamut(void* icc_data, size_t icc_size);
273 };
274
275 } // namespace ultrahdr
276
277 #endif // ULTRAHDR_ICC_H
278