diff --git a/autotests/read/psd/laba_16bit.png b/autotests/read/psd/laba_16bit.png new file mode 100644 index 0000000..d0db793 Binary files /dev/null and b/autotests/read/psd/laba_16bit.png differ diff --git a/autotests/read/psd/laba_16bit.psd b/autotests/read/psd/laba_16bit.psd new file mode 100644 index 0000000..308e036 Binary files /dev/null and b/autotests/read/psd/laba_16bit.psd differ diff --git a/autotests/read/psd/laba_8bit.png b/autotests/read/psd/laba_8bit.png new file mode 100644 index 0000000..1fd7e71 Binary files /dev/null and b/autotests/read/psd/laba_8bit.png differ diff --git a/autotests/read/psd/laba_8bit.psd b/autotests/read/psd/laba_8bit.psd new file mode 100644 index 0000000..215aa7a Binary files /dev/null and b/autotests/read/psd/laba_8bit.psd differ diff --git a/src/imageformats/psd.cpp b/src/imageformats/psd.cpp index dc6633a..078f361 100644 --- a/src/imageformats/psd.cpp +++ b/src/imageformats/psd.cpp @@ -3,7 +3,7 @@ SPDX-FileCopyrightText: 2003 Ignacio Castaño SPDX-FileCopyrightText: 2015 Alex Merry - SPDX-FileCopyrightText: 2022 Mirco Miranda + SPDX-FileCopyrightText: 2022 Mirco Miranda SPDX-License-Identifier: LGPL-2.0-or-later */ @@ -22,13 +22,15 @@ * Limitations of the current code: * - 32-bit float image are converted to 16-bit integer image. * NOTE: Qt 6.2 allow 32-bit float images (RGB only) - * - Other color spaces cannot be read due to lack of QImage support for - * color spaces other than RGB (and Grayscale): a conversion to - * RGB must be done. - * - The best way to convert between different color spaces is to use a - * color management engine (e.g. LittleCMS). - * - An approximate way is to ignore the color information and use - * literature formulas (possible but not recommended). + * - Other color spaces cannot directly be read due to lack of QImage support for + * color spaces other than RGB (and Grayscale). Where possible, a conversion + * to RGB is done: + * - CMYK images are converted using an approximated way that ignores the color + * information (ICC profile). + * - LAB images are converted to sRGB using literature formulas. + * + * NOTE: The best way to convert between different color spaces is to use a + * color management engine (e.g. LittleCMS). */ #include "psd_p.h" @@ -40,10 +42,24 @@ #include #include +#include + typedef quint32 uint; typedef quint16 ushort; typedef quint8 uchar; +/* The fast LAB conversion converts the image to linear sRgb instead to sRgb. + * This should not be a problem because the Qt's QColorSpace supports the linear + * sRgb colorspace. + * + * Using linear conversion, the loading speed is improved by 4x. Anyway, if you are using + * an software that discard color info, you should comment it. + * + * At the time I'm writing (07/2022), Gwenview and Krita supports linear sRgb but KDE + * preview creator does not. This is the why, for now, it is disabled. + */ +//#define PSD_FAST_LAB_CONVERSION + namespace // Private. { enum ColorMode { @@ -547,6 +563,7 @@ static bool IsSupported(const PSDHeader &header) header.color_mode != CM_INDEXED && header.color_mode != CM_DUOTONE && header.color_mode != CM_CMYK && + header.color_mode != CM_LABCOLOR && header.color_mode != CM_BITMAP) { return false; } @@ -615,12 +632,18 @@ static QImage::Format imageFormat(const PSDHeader &header, qint32 alpha) else format = header.channel_count < 4 ? QImage::Format_RGB888 : QImage::Format_RGBA8888; break; - case CM_CMYK: // PSD supports CMYK 8-bits and 16-bits only + case CM_CMYK: // Photoshop supports CMYK 8-bits and 16-bits only if (header.depth == 16) format = header.channel_count < 5 || alpha >= 0 ? QImage::Format_RGBX64 : QImage::Format_RGBA64; else if (header.depth == 8) format = header.channel_count < 5 || alpha >= 0 ? QImage::Format_RGB888 : QImage::Format_RGBA8888; break; + case CM_LABCOLOR: // Photoshop supports LAB 8-bits and 16-bits only + if (header.depth == 16) + format = header.channel_count < 4 ? QImage::Format_RGBX64 : QImage::Format_RGBA64; + else if (header.depth == 8) + format = header.channel_count < 4 ? QImage::Format_RGB888 : QImage::Format_RGBA8888; + break; case CM_GRAYSCALE: case CM_DUOTONE: format = header.depth == 8 ? QImage::Format_Grayscale8 : QImage::Format_Grayscale16; @@ -679,14 +702,6 @@ inline quint32 xchg(quint32 v) { #endif } -inline qint32 xchg(qint32 v) { -#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN - return qint32( (quint32(v)>>24) | ((quint32(v) & 0x00FF0000)>>8) | ((quint32(v) & 0x0000FF00)<<8) | (quint32(v)<<24) ); -#else - return v; // never tested -#endif -} - template inline void planarToChunchy(uchar *target, const char *source, qint32 width, qint32 c, qint32 cn) { @@ -719,7 +734,7 @@ inline void monoInvert(uchar *target, const char* source, qint32 bytes) } template -inline void cmykToRgb(uchar *target, qint32 targetChannels, const char *source, qint32 sourceChannels, qint32 width, bool noAlpha) +inline void cmykToRgb(uchar *target, qint32 targetChannels, const char *source, qint32 sourceChannels, qint32 width, bool noAlpha = false) { auto s = reinterpret_cast(source); auto t = reinterpret_cast(target); @@ -732,10 +747,10 @@ inline void cmykToRgb(uchar *target, qint32 targetChannels, const char *source, for (qint32 w = 0; w < width; ++w) { auto ps = s + sourceChannels * w; - auto C = 1 - *(ps + 0) / double(max); - auto M = 1 - *(ps + 1) / double(max); - auto Y = 1 - *(ps + 2) / double(max); - auto K = 1 - *(ps + 3) / double(max); + auto C = 1 - *(ps + 0) / max; + auto M = 1 - *(ps + 1) / max; + auto Y = 1 - *(ps + 2) / max; + auto K = 1 - *(ps + 3) / max; auto pt = t + targetChannels * w; *(pt + 0) = T(std::min(max - (C * (1 - K) + K) * max + 0.5, max)); @@ -750,6 +765,67 @@ inline void cmykToRgb(uchar *target, qint32 targetChannels, const char *source, } } +inline double finv(double v) +{ + return (v > 6.0 / 29.0 ? v * v * v : (v - 16.0 / 116.0) / 7.787); +} + +inline double gammaCorrection(double linear) +{ +#ifdef PSD_FAST_LAB_CONVERSION + return linear; +#else + // NOTE: pow() slow down the performance by a 4 factor :( + return (linear > 0.0031308 ? 1.055 * std::pow(linear, 1.0 / 2.4) - 0.055 : 12.92 * linear); +#endif +} + +template +inline void labToRgb(uchar *target, qint32 targetChannels, const char *source, qint32 sourceChannels, qint32 width, bool noAlpha = false) +{ + auto s = reinterpret_cast(source); + auto t = reinterpret_cast(target); + auto max = double(std::numeric_limits::max()); + + if (sourceChannels < 3) { + qDebug() << "labToRgb: image is not a valid LAB!"; + return; + } + + for (qint32 w = 0; w < width; ++w) { + auto ps = s + sourceChannels * w; + auto L = (*(ps + 0) / max) * 100.0; + auto A = (*(ps + 1) / max) * 255.0 - 128.0; + auto B = (*(ps + 2) / max) * 255.0 - 128.0; + + // converting LAB to XYZ (D65 illuminant) + auto Y = (L + 16.0) / 116.0; + auto X = A / 500.0 + Y; + auto Z = Y - B / 200.0; + + // NOTE: use the constants of the illuminant of the target RGB color space + X = finv(X) * 0.9504; // D50: * 0.9642 + Y = finv(Y) * 1.0000; // D50: * 1.0000 + Z = finv(Z) * 1.0888; // D50: * 0.8251 + + // converting XYZ to sRGB (sRGB illuminant is D65) + auto r = gammaCorrection( 3.24071 * X - 1.53726 * Y - 0.498571 * Z); + auto g = gammaCorrection(- 0.969258 * X + 1.87599 * Y + 0.0415557 * Z); + auto b = gammaCorrection( 0.0556352 * X - 0.203996 * Y + 1.05707 * Z); + + auto pt = t + targetChannels * w; + *(pt + 0) = T(std::max(std::min(r * max + 0.5, max), 0.0)); + *(pt + 1) = T(std::max(std::min(g * max + 0.5, max), 0.0)); + *(pt + 2) = T(std::max(std::min(b * max + 0.5, max), 0.0)); + if (targetChannels == 4) { + if (sourceChannels >= 4 && !noAlpha) + *(pt + 3) = *(ps + 3); + else + *(pt + 3) = std::numeric_limits::max(); + } + } +} + bool readChannel(QByteArray& target, QDataStream &stream, quint32 compressedSize, quint16 compression) { if (compression) { @@ -895,13 +971,7 @@ static bool LoadPSD(QDataStream &stream, const PSDHeader &header, QImage &img) planarToChunchy(scanLine, rawStride.data(), header.width, c, header.channel_count); } else if (header.depth == 32) { // Not currently used - // LAB float uses LAB real values: L(0 to 100), a/b(-128 to 127) - if (header.color_mode == CM_LABCOLOR && c == 0) - planarToChunchyFloat(scanLine, rawStride.data(), header.width, c, header.channel_count); - else if (header.color_mode == CM_LABCOLOR && c < 3) - planarToChunchyFloat(scanLine, rawStride.data(), header.width, c, header.channel_count); - else // RGB, gray, spots, etc... - planarToChunchyFloat(scanLine, rawStride.data(), header.width, c, header.channel_count); + planarToChunchyFloat(scanLine, rawStride.data(), header.width, c, header.channel_count); } } @@ -912,6 +982,12 @@ static bool LoadPSD(QDataStream &stream, const PSDHeader &header, QImage &img) else cmykToRgb(img.scanLine(y), imgChannels, psdScanline.data(), header.channel_count, header.width, alpha >= 0); } + if (header.color_mode == CM_LABCOLOR) { + if (header.depth == 8) + labToRgb(img.scanLine(y), imgChannels, psdScanline.data(), header.channel_count, header.width); + else + labToRgb(img.scanLine(y), imgChannels, psdScanline.data(), header.channel_count, header.width); + } } } else { @@ -941,6 +1017,15 @@ static bool LoadPSD(QDataStream &stream, const PSDHeader &header, QImage &img) } } + // LAB conversion generates a sRGB image + if (header.color_mode == CM_LABCOLOR) { +#ifdef PSD_FAST_LAB_CONVERSION + img.setColorSpace(QColorSpace(QColorSpace::SRgbLinear)); +#else + img.setColorSpace(QColorSpace(QColorSpace::SRgb)); +#endif + } + // Resolution info if (!setResolution(img, irs)) { // qDebug() << "No resolution info found!";