SkColorSpace.cpp revision 1f2fff2544a9dc6a0f169a017d374eca9f04c6b5
1/* 2 * Copyright 2016 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8#include "SkColorSpace.h" 9#include "SkColorSpace_Base.h" 10#include "SkColorSpace_XYZ.h" 11#include "SkColorSpacePriv.h" 12#include "SkOnce.h" 13#include "SkPoint3.h" 14 15bool SkColorSpacePrimaries::toXYZD50(SkMatrix44* toXYZ_D50) const { 16 if (!is_zero_to_one(fRX) || !is_zero_to_one(fRY) || 17 !is_zero_to_one(fGX) || !is_zero_to_one(fGY) || 18 !is_zero_to_one(fBX) || !is_zero_to_one(fBY) || 19 !is_zero_to_one(fWX) || !is_zero_to_one(fWY)) 20 { 21 return false; 22 } 23 24 // First, we need to convert xy values (primaries) to XYZ. 25 SkMatrix primaries; 26 primaries.setAll( fRX, fGX, fBX, 27 fRY, fGY, fBY, 28 1.0f - fRX - fRY, 1.0f - fGX - fGY, 1.0f - fBX - fBY); 29 SkMatrix primariesInv; 30 if (!primaries.invert(&primariesInv)) { 31 return false; 32 } 33 34 // Assumes that Y is 1.0f. 35 SkVector3 wXYZ = SkVector3::Make(fWX / fWY, 1.0f, (1.0f - fWX - fWY) / fWY); 36 SkVector3 XYZ; 37 XYZ.fX = primariesInv[0] * wXYZ.fX + primariesInv[1] * wXYZ.fY + primariesInv[2] * wXYZ.fZ; 38 XYZ.fY = primariesInv[3] * wXYZ.fX + primariesInv[4] * wXYZ.fY + primariesInv[5] * wXYZ.fZ; 39 XYZ.fZ = primariesInv[6] * wXYZ.fX + primariesInv[7] * wXYZ.fY + primariesInv[8] * wXYZ.fZ; 40 SkMatrix toXYZ; 41 toXYZ.setAll(XYZ.fX, 0.0f, 0.0f, 42 0.0f, XYZ.fY, 0.0f, 43 0.0f, 0.0f, XYZ.fZ); 44 toXYZ.postConcat(primaries); 45 46 // Now convert toXYZ matrix to toXYZD50. 47 SkVector3 wXYZD50 = SkVector3::Make(0.96422f, 1.0f, 0.82521f); 48 49 // Calculate the chromatic adaptation matrix. We will use the Bradford method, thus 50 // the matrices below. The Bradford method is used by Adobe and is widely considered 51 // to be the best. 52 SkMatrix mA, mAInv; 53 mA.setAll(+0.8951f, +0.2664f, -0.1614f, 54 -0.7502f, +1.7135f, +0.0367f, 55 +0.0389f, -0.0685f, +1.0296f); 56 mAInv.setAll(+0.9869929f, -0.1470543f, +0.1599627f, 57 +0.4323053f, +0.5183603f, +0.0492912f, 58 -0.0085287f, +0.0400428f, +0.9684867f); 59 60 SkVector3 srcCone; 61 srcCone.fX = mA[0] * wXYZ.fX + mA[1] * wXYZ.fY + mA[2] * wXYZ.fZ; 62 srcCone.fY = mA[3] * wXYZ.fX + mA[4] * wXYZ.fY + mA[5] * wXYZ.fZ; 63 srcCone.fZ = mA[6] * wXYZ.fX + mA[7] * wXYZ.fY + mA[8] * wXYZ.fZ; 64 SkVector3 dstCone; 65 dstCone.fX = mA[0] * wXYZD50.fX + mA[1] * wXYZD50.fY + mA[2] * wXYZD50.fZ; 66 dstCone.fY = mA[3] * wXYZD50.fX + mA[4] * wXYZD50.fY + mA[5] * wXYZD50.fZ; 67 dstCone.fZ = mA[6] * wXYZD50.fX + mA[7] * wXYZD50.fY + mA[8] * wXYZD50.fZ; 68 69 SkMatrix DXToD50; 70 DXToD50.setIdentity(); 71 DXToD50[0] = dstCone.fX / srcCone.fX; 72 DXToD50[4] = dstCone.fY / srcCone.fY; 73 DXToD50[8] = dstCone.fZ / srcCone.fZ; 74 DXToD50.postConcat(mAInv); 75 DXToD50.preConcat(mA); 76 77 toXYZ.postConcat(DXToD50); 78 toXYZ_D50->set3x3(toXYZ[0], toXYZ[3], toXYZ[6], 79 toXYZ[1], toXYZ[4], toXYZ[7], 80 toXYZ[2], toXYZ[5], toXYZ[8]); 81 return true; 82} 83 84/////////////////////////////////////////////////////////////////////////////////////////////////// 85 86SkColorSpace_Base::SkColorSpace_Base(sk_sp<SkData> profileData) 87 : fProfileData(std::move(profileData)) 88{} 89 90/** 91 * Checks if our toXYZ matrix is a close match to a known color gamut. 92 * 93 * @param toXYZD50 transformation matrix deduced from profile data 94 * @param standard 3x3 canonical transformation matrix 95 */ 96static bool xyz_almost_equal(const SkMatrix44& toXYZD50, const float* standard) { 97 return color_space_almost_equal(toXYZD50.getFloat(0, 0), standard[0]) && 98 color_space_almost_equal(toXYZD50.getFloat(0, 1), standard[1]) && 99 color_space_almost_equal(toXYZD50.getFloat(0, 2), standard[2]) && 100 color_space_almost_equal(toXYZD50.getFloat(1, 0), standard[3]) && 101 color_space_almost_equal(toXYZD50.getFloat(1, 1), standard[4]) && 102 color_space_almost_equal(toXYZD50.getFloat(1, 2), standard[5]) && 103 color_space_almost_equal(toXYZD50.getFloat(2, 0), standard[6]) && 104 color_space_almost_equal(toXYZD50.getFloat(2, 1), standard[7]) && 105 color_space_almost_equal(toXYZD50.getFloat(2, 2), standard[8]) && 106 color_space_almost_equal(toXYZD50.getFloat(0, 3), 0.0f) && 107 color_space_almost_equal(toXYZD50.getFloat(1, 3), 0.0f) && 108 color_space_almost_equal(toXYZD50.getFloat(2, 3), 0.0f) && 109 color_space_almost_equal(toXYZD50.getFloat(3, 0), 0.0f) && 110 color_space_almost_equal(toXYZD50.getFloat(3, 1), 0.0f) && 111 color_space_almost_equal(toXYZD50.getFloat(3, 2), 0.0f) && 112 color_space_almost_equal(toXYZD50.getFloat(3, 3), 1.0f); 113} 114 115sk_sp<SkColorSpace> SkColorSpace_Base::MakeRGB(SkGammaNamed gammaNamed, const SkMatrix44& toXYZD50) 116{ 117 switch (gammaNamed) { 118 case kSRGB_SkGammaNamed: 119 if (xyz_almost_equal(toXYZD50, gSRGB_toXYZD50)) { 120 return SkColorSpace::MakeNamed(kSRGB_Named); 121 } 122 break; 123 case k2Dot2Curve_SkGammaNamed: 124 if (xyz_almost_equal(toXYZD50, gAdobeRGB_toXYZD50)) { 125 return SkColorSpace::MakeNamed(kAdobeRGB_Named); 126 } 127 break; 128 case kLinear_SkGammaNamed: 129 if (xyz_almost_equal(toXYZD50, gSRGB_toXYZD50)) { 130 return SkColorSpace::MakeNamed(kSRGBLinear_Named); 131 } 132 break; 133 case kNonStandard_SkGammaNamed: 134 // This is not allowed. 135 return nullptr; 136 default: 137 break; 138 } 139 140 return sk_sp<SkColorSpace>(new SkColorSpace_XYZ(gammaNamed, toXYZD50)); 141} 142 143sk_sp<SkColorSpace> SkColorSpace::MakeRGB(RenderTargetGamma gamma, const SkMatrix44& toXYZD50) { 144 switch (gamma) { 145 case kLinear_RenderTargetGamma: 146 return SkColorSpace_Base::MakeRGB(kLinear_SkGammaNamed, toXYZD50); 147 case kSRGB_RenderTargetGamma: 148 return SkColorSpace_Base::MakeRGB(kSRGB_SkGammaNamed, toXYZD50); 149 default: 150 return nullptr; 151 } 152} 153 154sk_sp<SkColorSpace> SkColorSpace::MakeRGB(const SkColorSpaceTransferFn& coeffs, 155 const SkMatrix44& toXYZD50) { 156 if (!is_valid_transfer_fn(coeffs)) { 157 return nullptr; 158 } 159 160 if (is_almost_srgb(coeffs)) { 161 return SkColorSpace::MakeRGB(kSRGB_RenderTargetGamma, toXYZD50); 162 } 163 164 if (is_almost_2dot2(coeffs)) { 165 return SkColorSpace_Base::MakeRGB(k2Dot2Curve_SkGammaNamed, toXYZD50); 166 } 167 168 if (is_almost_linear(coeffs)) { 169 return SkColorSpace_Base::MakeRGB(kLinear_SkGammaNamed, toXYZD50); 170 } 171 172 void* memory = sk_malloc_throw(sizeof(SkGammas) + sizeof(SkColorSpaceTransferFn)); 173 sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new (memory) SkGammas(3)); 174 SkColorSpaceTransferFn* fn = SkTAddOffset<SkColorSpaceTransferFn>(memory, sizeof(SkGammas)); 175 *fn = coeffs; 176 SkGammas::Data data; 177 data.fParamOffset = 0; 178 for (int channel = 0; channel < 3; ++channel) { 179 gammas->fType[channel] = SkGammas::Type::kParam_Type; 180 gammas->fData[channel] = data; 181 } 182 return sk_sp<SkColorSpace>(new SkColorSpace_XYZ(kNonStandard_SkGammaNamed, 183 std::move(gammas), toXYZD50, nullptr)); 184} 185 186static SkColorSpace* gAdobeRGB; 187static SkColorSpace* gSRGB; 188static SkColorSpace* gSRGBLinear; 189 190sk_sp<SkColorSpace> SkColorSpace::MakeNamed(Named named) { 191 static SkOnce sRGBOnce; 192 static SkOnce adobeRGBOnce; 193 static SkOnce sRGBLinearOnce; 194 195 switch (named) { 196 case kSRGB_Named: { 197 sRGBOnce([] { 198 SkMatrix44 srgbToxyzD50(SkMatrix44::kUninitialized_Constructor); 199 srgbToxyzD50.set3x3RowMajorf(gSRGB_toXYZD50); 200 201 // Force the mutable type mask to be computed. This avoids races. 202 (void)srgbToxyzD50.getType(); 203 gSRGB = new SkColorSpace_XYZ(kSRGB_SkGammaNamed, srgbToxyzD50); 204 }); 205 return sk_ref_sp<SkColorSpace>(gSRGB); 206 } 207 case kAdobeRGB_Named: { 208 adobeRGBOnce([] { 209 SkMatrix44 adobergbToxyzD50(SkMatrix44::kUninitialized_Constructor); 210 adobergbToxyzD50.set3x3RowMajorf(gAdobeRGB_toXYZD50); 211 212 // Force the mutable type mask to be computed. This avoids races. 213 (void)adobergbToxyzD50.getType(); 214 gAdobeRGB = new SkColorSpace_XYZ(k2Dot2Curve_SkGammaNamed, adobergbToxyzD50); 215 }); 216 return sk_ref_sp<SkColorSpace>(gAdobeRGB); 217 } 218 case kSRGBLinear_Named: { 219 sRGBLinearOnce([] { 220 SkMatrix44 srgbToxyzD50(SkMatrix44::kUninitialized_Constructor); 221 srgbToxyzD50.set3x3RowMajorf(gSRGB_toXYZD50); 222 223 // Force the mutable type mask to be computed. This avoids races. 224 (void)srgbToxyzD50.getType(); 225 gSRGBLinear = new SkColorSpace_XYZ(kLinear_SkGammaNamed, srgbToxyzD50); 226 }); 227 return sk_ref_sp<SkColorSpace>(gSRGBLinear); 228 } 229 default: 230 break; 231 } 232 return nullptr; 233} 234 235/////////////////////////////////////////////////////////////////////////////////////////////////// 236 237bool SkColorSpace::gammaCloseToSRGB() const { 238 return as_CSB(this)->onGammaCloseToSRGB(); 239} 240 241bool SkColorSpace::gammaIsLinear() const { 242 return as_CSB(this)->onGammaIsLinear(); 243} 244 245bool SkColorSpace::toXYZD50(SkMatrix44* toXYZD50) const { 246 const SkMatrix44* matrix = as_CSB(this)->toXYZD50(); 247 if (matrix) { 248 *toXYZD50 = *matrix; 249 return true; 250 } 251 252 return false; 253} 254 255/////////////////////////////////////////////////////////////////////////////////////////////////// 256 257enum Version { 258 k0_Version, // Initial version, header + flags for matrix and profile 259}; 260 261struct ColorSpaceHeader { 262 /** 263 * It is only valid to set zero or one flags. 264 * Setting multiple flags is invalid. 265 */ 266 267 /** 268 * If kMatrix_Flag is set, we will write 12 floats after the header. 269 */ 270 static constexpr uint8_t kMatrix_Flag = 1 << 0; 271 272 /** 273 * If kICC_Flag is set, we will write an ICC profile after the header. 274 * The ICC profile will be written as a uint32 size, followed immediately 275 * by the data (padded to 4 bytes). 276 */ 277 static constexpr uint8_t kICC_Flag = 1 << 1; 278 279 /** 280 * If kTransferFn_Flag is set, we will write 19 floats after the header. 281 * The first seven represent the transfer fn, and the next twelve are the 282 * matrix. 283 */ 284 static constexpr uint8_t kTransferFn_Flag = 1 << 3; 285 286 static ColorSpaceHeader Pack(Version version, uint8_t named, uint8_t gammaNamed, uint8_t flags) 287 { 288 ColorSpaceHeader header; 289 290 SkASSERT(k0_Version == version); 291 header.fVersion = (uint8_t) version; 292 293 SkASSERT(named <= SkColorSpace::kSRGBLinear_Named); 294 header.fNamed = (uint8_t) named; 295 296 SkASSERT(gammaNamed <= kNonStandard_SkGammaNamed); 297 header.fGammaNamed = (uint8_t) gammaNamed; 298 299 SkASSERT(flags <= kTransferFn_Flag); 300 header.fFlags = flags; 301 return header; 302 } 303 304 uint8_t fVersion; // Always zero 305 uint8_t fNamed; // Must be a SkColorSpace::Named 306 uint8_t fGammaNamed; // Must be a SkGammaNamed 307 uint8_t fFlags; // Some combination of the flags listed above 308}; 309 310size_t SkColorSpace::writeToMemory(void* memory) const { 311 // Start by trying the serialization fast path. If we haven't saved ICC profile data, 312 // we must have a profile that we can serialize easily. 313 if (!as_CSB(this)->fProfileData) { 314 // Profile data is mandatory for A2B0 color spaces. 315 SkASSERT(SkColorSpace_Base::Type::kXYZ == as_CSB(this)->type()); 316 const SkColorSpace_XYZ* thisXYZ = static_cast<const SkColorSpace_XYZ*>(this); 317 // If we have a named profile, only write the enum. 318 const SkGammaNamed gammaNamed = thisXYZ->gammaNamed(); 319 if (this == gSRGB) { 320 if (memory) { 321 *((ColorSpaceHeader*) memory) = 322 ColorSpaceHeader::Pack(k0_Version, kSRGB_Named, gammaNamed, 0); 323 } 324 return sizeof(ColorSpaceHeader); 325 } else if (this == gAdobeRGB) { 326 if (memory) { 327 *((ColorSpaceHeader*) memory) = 328 ColorSpaceHeader::Pack(k0_Version, kAdobeRGB_Named, gammaNamed, 0); 329 } 330 return sizeof(ColorSpaceHeader); 331 } else if (this == gSRGBLinear) { 332 if (memory) { 333 *((ColorSpaceHeader*) memory) = 334 ColorSpaceHeader::Pack(k0_Version, kSRGBLinear_Named, gammaNamed, 0); 335 } 336 return sizeof(ColorSpaceHeader); 337 } 338 339 // If we have a named gamma, write the enum and the matrix. 340 switch (gammaNamed) { 341 case kSRGB_SkGammaNamed: 342 case k2Dot2Curve_SkGammaNamed: 343 case kLinear_SkGammaNamed: { 344 if (memory) { 345 *((ColorSpaceHeader*) memory) = 346 ColorSpaceHeader::Pack(k0_Version, 0, gammaNamed, 347 ColorSpaceHeader::kMatrix_Flag); 348 memory = SkTAddOffset<void>(memory, sizeof(ColorSpaceHeader)); 349 thisXYZ->toXYZD50()->as3x4RowMajorf((float*) memory); 350 } 351 return sizeof(ColorSpaceHeader) + 12 * sizeof(float); 352 } 353 default: { 354 const SkGammas* gammas = thisXYZ->gammas(); 355 SkASSERT(gammas); 356 SkASSERT(gammas->isParametric(0)); 357 SkASSERT(gammas->isParametric(1)); 358 SkASSERT(gammas->isParametric(2)); 359 SkASSERT(gammas->data(0) == gammas->data(1)); 360 SkASSERT(gammas->data(0) == gammas->data(2)); 361 362 if (memory) { 363 *((ColorSpaceHeader*) memory) = 364 ColorSpaceHeader::Pack(k0_Version, 0, thisXYZ->fGammaNamed, 365 ColorSpaceHeader::kTransferFn_Flag); 366 memory = SkTAddOffset<void>(memory, sizeof(ColorSpaceHeader)); 367 368 *(((float*) memory) + 0) = gammas->params(0).fA; 369 *(((float*) memory) + 1) = gammas->params(0).fB; 370 *(((float*) memory) + 2) = gammas->params(0).fC; 371 *(((float*) memory) + 3) = gammas->params(0).fD; 372 *(((float*) memory) + 4) = gammas->params(0).fE; 373 *(((float*) memory) + 5) = gammas->params(0).fF; 374 *(((float*) memory) + 6) = gammas->params(0).fG; 375 memory = SkTAddOffset<void>(memory, 7 * sizeof(float)); 376 377 thisXYZ->fToXYZD50.as3x4RowMajorf((float*) memory); 378 } 379 380 return sizeof(ColorSpaceHeader) + 19 * sizeof(float); 381 } 382 } 383 } 384 385 // Otherwise, serialize the ICC data. 386 size_t profileSize = as_CSB(this)->fProfileData->size(); 387 if (SkAlign4(profileSize) != (uint32_t) SkAlign4(profileSize)) { 388 return 0; 389 } 390 391 if (memory) { 392 *((ColorSpaceHeader*) memory) = ColorSpaceHeader::Pack(k0_Version, 0, 393 kNonStandard_SkGammaNamed, 394 ColorSpaceHeader::kICC_Flag); 395 memory = SkTAddOffset<void>(memory, sizeof(ColorSpaceHeader)); 396 397 *((uint32_t*) memory) = (uint32_t) SkAlign4(profileSize); 398 memory = SkTAddOffset<void>(memory, sizeof(uint32_t)); 399 400 memcpy(memory, as_CSB(this)->fProfileData->data(), profileSize); 401 memset(SkTAddOffset<void>(memory, profileSize), 0, SkAlign4(profileSize) - profileSize); 402 } 403 return sizeof(ColorSpaceHeader) + sizeof(uint32_t) + SkAlign4(profileSize); 404} 405 406sk_sp<SkData> SkColorSpace::serialize() const { 407 size_t size = this->writeToMemory(nullptr); 408 if (0 == size) { 409 return nullptr; 410 } 411 412 sk_sp<SkData> data = SkData::MakeUninitialized(size); 413 this->writeToMemory(data->writable_data()); 414 return data; 415} 416 417sk_sp<SkColorSpace> SkColorSpace::Deserialize(const void* data, size_t length) { 418 if (length < sizeof(ColorSpaceHeader)) { 419 return nullptr; 420 } 421 422 ColorSpaceHeader header = *((const ColorSpaceHeader*) data); 423 data = SkTAddOffset<const void>(data, sizeof(ColorSpaceHeader)); 424 length -= sizeof(ColorSpaceHeader); 425 if (0 == header.fFlags) { 426 return MakeNamed((Named) header.fNamed); 427 } 428 429 switch ((SkGammaNamed) header.fGammaNamed) { 430 case kSRGB_SkGammaNamed: 431 case k2Dot2Curve_SkGammaNamed: 432 case kLinear_SkGammaNamed: { 433 if (ColorSpaceHeader::kMatrix_Flag != header.fFlags || length < 12 * sizeof(float)) { 434 return nullptr; 435 } 436 437 SkMatrix44 toXYZ(SkMatrix44::kUninitialized_Constructor); 438 toXYZ.set3x4RowMajorf((const float*) data); 439 return SkColorSpace_Base::MakeRGB((SkGammaNamed) header.fGammaNamed, toXYZ); 440 } 441 default: 442 break; 443 } 444 445 switch (header.fFlags) { 446 case ColorSpaceHeader::kICC_Flag: { 447 if (length < sizeof(uint32_t)) { 448 return nullptr; 449 } 450 451 uint32_t profileSize = *((uint32_t*) data); 452 data = SkTAddOffset<const void>(data, sizeof(uint32_t)); 453 length -= sizeof(uint32_t); 454 if (length < profileSize) { 455 return nullptr; 456 } 457 458 return MakeICC(data, profileSize); 459 } 460 case ColorSpaceHeader::kTransferFn_Flag: { 461 if (length < 19 * sizeof(float)) { 462 return nullptr; 463 } 464 465 SkColorSpaceTransferFn transferFn; 466 transferFn.fA = *(((const float*) data) + 0); 467 transferFn.fB = *(((const float*) data) + 1); 468 transferFn.fC = *(((const float*) data) + 2); 469 transferFn.fD = *(((const float*) data) + 3); 470 transferFn.fE = *(((const float*) data) + 4); 471 transferFn.fF = *(((const float*) data) + 5); 472 transferFn.fG = *(((const float*) data) + 6); 473 data = SkTAddOffset<const void>(data, 7 * sizeof(float)); 474 475 SkMatrix44 toXYZ(SkMatrix44::kUninitialized_Constructor); 476 toXYZ.set3x4RowMajorf((const float*) data); 477 return SkColorSpace::MakeRGB(transferFn, toXYZ); 478 } 479 default: 480 return nullptr; 481 } 482} 483 484bool SkColorSpace::Equals(const SkColorSpace* src, const SkColorSpace* dst) { 485 if (src == dst) { 486 return true; 487 } 488 489 if (!src || !dst) { 490 return false; 491 } 492 493 SkData* srcData = as_CSB(src)->fProfileData.get(); 494 SkData* dstData = as_CSB(dst)->fProfileData.get(); 495 if (srcData || dstData) { 496 if (srcData && dstData) { 497 return srcData->size() == dstData->size() && 498 0 == memcmp(srcData->data(), dstData->data(), srcData->size()); 499 } 500 501 return false; 502 } 503 504 // profiles are mandatory for A2B0 color spaces 505 SkASSERT(as_CSB(src)->type() == SkColorSpace_Base::Type::kXYZ); 506 const SkColorSpace_XYZ* srcXYZ = static_cast<const SkColorSpace_XYZ*>(src); 507 const SkColorSpace_XYZ* dstXYZ = static_cast<const SkColorSpace_XYZ*>(dst); 508 509 if (srcXYZ->gammaNamed() != dstXYZ->gammaNamed()) { 510 return false; 511 } 512 513 switch (srcXYZ->gammaNamed()) { 514 case kSRGB_SkGammaNamed: 515 case k2Dot2Curve_SkGammaNamed: 516 case kLinear_SkGammaNamed: 517 if (srcXYZ->toXYZD50Hash() == dstXYZ->toXYZD50Hash()) { 518 SkASSERT(*srcXYZ->toXYZD50() == *dstXYZ->toXYZD50() && "Hash collision"); 519 return true; 520 } 521 return false; 522 default: 523 // It is unlikely that we will reach this case. 524 sk_sp<SkData> serializedSrcData = src->serialize(); 525 sk_sp<SkData> serializedDstData = dst->serialize(); 526 return serializedSrcData->size() == serializedDstData->size() && 527 0 == memcmp(serializedSrcData->data(), serializedDstData->data(), 528 serializedSrcData->size()); 529 } 530} 531