GIT_SILENT Upgrade ECM and KF version requirements for 5.107.0 release.

- 1-bit writer: checks where is black and use NOT operator only if needed
- Fix images with witdh == 65536(*)
- Checks result of disk writes and reads on all formats

(*) PCX formats support images with with of 65536 but only if the header field bytesPerLine is valid (no overflow). This means that the width 65536 is supported on 1bpp images only.
The previous version of the plugins wrote an image with width of 65536px in the wrong way and it was unable to read it (wrong image returned). I verified that Photoshop and Gimp weren't able to read the image either.

(cherry picked from commit d57ff91f8b)

CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 3.16)
 project(KImageFormats)
 
 include(FeatureSummary)
-find_package(ECM 5.103.0  NO_MODULE)
+find_package(ECM 5.107.0  NO_MODULE)
 set_package_properties(ECM PROPERTIES TYPE REQUIRED DESCRIPTION "Extra CMake Modules." URL "https://commits.kde.org/extra-cmake-modules")
 feature_summary(WHAT REQUIRED_PACKAGES_NOT_FOUND FATAL_ON_MISSING_REQUIRED_PACKAGES)
 

autotests/readtest.cpp

@@ -159,17 +159,22 @@ int main(int argc, char **argv)
             QTextStream(stdout) << "* Run on RANDOM ACCESS device\n";
         }
         for (const QFileInfo &fi : lstImgDir) {
-            if (!fi.suffix().compare("png", Qt::CaseInsensitive)) {
+            if (!fi.suffix().compare("png", Qt::CaseInsensitive) || !fi.suffix().compare("tif", Qt::CaseInsensitive)) {
                 continue;
             }
             int suffixPos = fi.filePath().count() - suffix.count();
             QString inputfile = fi.filePath();
-            QString expfile = fi.filePath().replace(suffixPos, suffix.count(), QStringLiteral("png"));
+            QString fmt = QStringLiteral("png");
+            QString expfile = fi.filePath().replace(suffixPos, suffix.count(), fmt);
+            if (!QFile::exists(expfile)) { // try with tiff
+                fmt = QStringLiteral("tif");
+                expfile = fi.filePath().replace(suffixPos, suffix.count(), fmt);
+            }
             QString expfilename = QFileInfo(expfile).fileName();
 
             std::unique_ptr<QIODevice> inputDevice(seq ? new SequentialFile(inputfile) : new QFile(inputfile));
             QImageReader inputReader(inputDevice.get(), format);
-            QImageReader expReader(expfile, "png");
+            QImageReader expReader(expfile, fmt.toLatin1());
 
             QImage inputImage;
             QImage expImage;

src/imageformats/pcx.cpp

@@ -230,7 +230,7 @@ PCXHEADER::PCXHEADER()
     s >> *this;
 }
 
-static void readLine(QDataStream &s, QByteArray &buf, const PCXHEADER &header)
+static bool readLine(QDataStream &s, QByteArray &buf, const PCXHEADER &header)
 {
     quint32 i = 0;
     quint32 size = buf.size();
@@ -257,9 +257,11 @@ static void readLine(QDataStream &s, QByteArray &buf, const PCXHEADER &header)
             buf[i++] = byte;
         }
     }
+
+    return (s.status() == QDataStream::Ok);
 }
 
-static void readImage1(QImage &img, QDataStream &s, const PCXHEADER &header)
+static bool readImage1(QImage &img, QDataStream &s, const PCXHEADER &header)
 {
     QByteArray buf(header.BytesPerLine, 0);
 
@@ -268,16 +270,18 @@ static void readImage1(QImage &img, QDataStream &s, const PCXHEADER &header)
 
     if (img.isNull()) {
         qWarning() << "Failed to allocate image, invalid dimensions?" << QSize(header.width(), header.height());
-        return;
+        return false;
     }
 
     for (int y = 0; y < header.height(); ++y) {
         if (s.atEnd()) {
-            img = QImage();
-            return;
+            return false;
+        }
+
+        if (!readLine(s, buf, header)) {
+            return false;
         }
 
-        readLine(s, buf, header);
         uchar *p = img.scanLine(y);
         unsigned int bpl = qMin((quint16)((header.width() + 7) / 8), header.BytesPerLine);
         for (unsigned int x = 0; x < bpl; ++x) {
@@ -288,9 +292,11 @@ static void readImage1(QImage &img, QDataStream &s, const PCXHEADER &header)
     // Set the color palette
     img.setColor(0, qRgb(0, 0, 0));
     img.setColor(1, qRgb(255, 255, 255));
+
+    return true;
 }
 
-static void readImage4(QImage &img, QDataStream &s, const PCXHEADER &header)
+static bool readImage4(QImage &img, QDataStream &s, const PCXHEADER &header)
 {
     QByteArray buf(header.BytesPerLine * 4, 0);
     QByteArray pixbuf(header.width(), 0);
@@ -299,17 +305,18 @@ static void readImage4(QImage &img, QDataStream &s, const PCXHEADER &header)
     img.setColorCount(16);
     if (img.isNull()) {
         qWarning() << "Failed to allocate image, invalid dimensions?" << QSize(header.width(), header.height());
-        return;
+        return false;
     }
 
     for (int y = 0; y < header.height(); ++y) {
         if (s.atEnd()) {
-            img = QImage();
-            return;
+            return false;
         }
 
         pixbuf.fill(0);
-        readLine(s, buf, header);
+        if (!readLine(s, buf, header)) {
+            return false;
+        }
 
         for (int i = 0; i < 4; i++) {
             quint32 offset = i * header.BytesPerLine;
@@ -333,9 +340,11 @@ static void readImage4(QImage &img, QDataStream &s, const PCXHEADER &header)
     for (int i = 0; i < 16; ++i) {
         img.setColor(i, header.ColorMap.color(i));
     }
+
+    return true;
 }
 
-static void readImage8(QImage &img, QDataStream &s, const PCXHEADER &header)
+static bool readImage8(QImage &img, QDataStream &s, const PCXHEADER &header)
 {
     QByteArray buf(header.BytesPerLine, 0);
 
@@ -344,21 +353,21 @@ static void readImage8(QImage &img, QDataStream &s, const PCXHEADER &header)
 
     if (img.isNull()) {
         qWarning() << "Failed to allocate image, invalid dimensions?" << QSize(header.width(), header.height());
-        return;
+        return false;
     }
 
     for (int y = 0; y < header.height(); ++y) {
         if (s.atEnd()) {
-            img = QImage();
-            return;
+            return false;
         }
 
-        readLine(s, buf, header);
+        if (!readLine(s, buf, header)) {
+            return false;
+        }
 
         uchar *p = img.scanLine(y);
-
         if (!p) {
-            return;
+            return false;
         }
 
         unsigned int bpl = qMin(header.BytesPerLine, (quint16)header.width());
@@ -367,10 +376,21 @@ static void readImage8(QImage &img, QDataStream &s, const PCXHEADER &header)
         }
     }
 
-    quint8 flag;
-    s >> flag;
-    //   qDebug() << "Palette Flag: " << flag;
+    // by specification, the extended palette starts at file.size() - 769
+    quint8 flag = 0;
+    if (auto device = s.device()) {
+        if (device->isSequential()) {
+            while (flag != 12 && s.status() == QDataStream::Ok) {
+                s >> flag;
+            }
+        }
+        else {
+            device->seek(device->size() - 769);
+            s >> flag;
+        }
+    }
 
+    //   qDebug() << "Palette Flag: " << flag;
     if (flag == 12 && (header.Version == 5 || header.Version == 2)) {
         // Read the palette
         quint8 r;
@@ -381,9 +401,11 @@ static void readImage8(QImage &img, QDataStream &s, const PCXHEADER &header)
             img.setColor(i, qRgb(r, g, b));
         }
     }
+
+    return (s.status() == QDataStream::Ok);
 }
 
-static void readImage24(QImage &img, QDataStream &s, const PCXHEADER &header)
+static bool readImage24(QImage &img, QDataStream &s, const PCXHEADER &header)
 {
     QByteArray r_buf(header.BytesPerLine, 0);
     QByteArray g_buf(header.BytesPerLine, 0);
@@ -393,27 +415,34 @@ static void readImage24(QImage &img, QDataStream &s, const PCXHEADER &header)
 
     if (img.isNull()) {
         qWarning() << "Failed to allocate image, invalid dimensions?" << QSize(header.width(), header.height());
-        return;
+        return false;
     }
 
     for (int y = 0; y < header.height(); ++y) {
         if (s.atEnd()) {
-            img = QImage();
-            return;
+            return false;
         }
 
-        readLine(s, r_buf, header);
-        readLine(s, g_buf, header);
-        readLine(s, b_buf, header);
+        if (!readLine(s, r_buf, header)) {
+            return false;
+        }
+        if (!readLine(s, g_buf, header)) {
+            return false;
+        }
+        if (!readLine(s, b_buf, header)) {
+            return false;
+        }
 
         uint *p = (uint *)img.scanLine(y);
         for (int x = 0; x < header.width(); ++x) {
             p[x] = qRgb(r_buf[x], g_buf[x], b_buf[x]);
         }
     }
+
+    return true;
 }
 
-static void writeLine(QDataStream &s, QByteArray &buf)
+static bool writeLine(QDataStream &s, QByteArray &buf)
 {
     quint32 i = 0;
     quint32 size = buf.size();
@@ -439,15 +468,26 @@ static void writeLine(QDataStream &s, QByteArray &buf)
 
         s << data;
     }
+    return (s.status() == QDataStream::Ok);
 }
 
-static void writeImage1(QImage &img, QDataStream &s, PCXHEADER &header)
+static bool writeImage1(QImage &img, QDataStream &s, PCXHEADER &header)
 {
-    img = img.convertToFormat(QImage::Format_Mono);
+    if (img.format() != QImage::Format_Mono) {
+        img = img.convertToFormat(QImage::Format_Mono);
+    }
+    if (img.isNull() || img.colorCount() < 1) {
+        return false;
+    }
+    auto rgb = img.color(0);
+    auto minIsBlack = (qRed(rgb) + qGreen(rgb) + qBlue(rgb)) / 3 < 127;
 
     header.Bpp = 1;
     header.NPlanes = 1;
     header.BytesPerLine = img.bytesPerLine();
+    if (header.BytesPerLine == 0) {
+        return false;
+    }
 
     s << header;
 
@@ -458,18 +498,24 @@ static void writeImage1(QImage &img, QDataStream &s, PCXHEADER &header)
 
         // Invert as QImage uses reverse palette for monochrome images?
         for (int i = 0; i < header.BytesPerLine; ++i) {
-            buf[i] = ~p[i];
+            buf[i] = minIsBlack ? p[i] : ~p[i];
         }
 
-        writeLine(s, buf);
+        if (!writeLine(s, buf)) {
+            return false;
+        }
     }
+    return true;
 }
 
-static void writeImage4(QImage &img, QDataStream &s, PCXHEADER &header)
+static bool writeImage4(QImage &img, QDataStream &s, PCXHEADER &header)
 {
     header.Bpp = 1;
     header.NPlanes = 4;
     header.BytesPerLine = header.width() / 8;
+    if (header.BytesPerLine == 0) {
+        return false;
+    }
 
     for (int i = 0; i < 16; ++i) {
         header.ColorMap.setColor(i, img.color(i));
@@ -499,16 +545,22 @@ static void writeImage4(QImage &img, QDataStream &s, PCXHEADER &header)
         }
 
         for (int i = 0; i < 4; ++i) {
-            writeLine(s, buf[i]);
+            if (!writeLine(s, buf[i])) {
+                return false;
+            }
         }
     }
+    return true;
 }
 
-static void writeImage8(QImage &img, QDataStream &s, PCXHEADER &header)
+static bool writeImage8(QImage &img, QDataStream &s, PCXHEADER &header)
 {
     header.Bpp = 8;
     header.NPlanes = 1;
     header.BytesPerLine = img.bytesPerLine();
+    if (header.BytesPerLine == 0) {
+        return false;
+    }
 
     s << header;
 
@@ -521,7 +573,9 @@ static void writeImage8(QImage &img, QDataStream &s, PCXHEADER &header)
             buf[i] = p[i];
         }
 
-        writeLine(s, buf);
+        if (!writeLine(s, buf)) {
+            return false;
+        }
     }
 
     // Write palette flag
@@ -532,13 +586,25 @@ static void writeImage8(QImage &img, QDataStream &s, PCXHEADER &header)
     for (int i = 0; i < 256; ++i) {
         s << RGB::from(img.color(i));
     }
+
+    return (s.status() == QDataStream::Ok);
 }
 
-static void writeImage24(QImage &img, QDataStream &s, PCXHEADER &header)
+static bool writeImage24(QImage &img, QDataStream &s, PCXHEADER &header)
 {
     header.Bpp = 8;
     header.NPlanes = 3;
     header.BytesPerLine = header.width();
+    if (header.BytesPerLine == 0) {
+        return false;
+    }
+
+    if (img.format() != QImage::Format_ARGB32 && img.format() != QImage::Format_RGB32) {
+        img = img.convertToFormat(QImage::Format_RGB32);
+    }
+    if (img.isNull()) {
+        return false;
+    }
 
     s << header;
 
@@ -547,7 +613,7 @@ static void writeImage24(QImage &img, QDataStream &s, PCXHEADER &header)
     QByteArray b_buf(header.width(), 0);
 
     for (int y = 0; y < header.height(); ++y) {
-        uint *p = (uint *)img.scanLine(y);
+        auto p = (QRgb*)img.scanLine(y);
 
         for (int x = 0; x < header.width(); ++x) {
             QRgb rgb = *p++;
@@ -556,10 +622,18 @@ static void writeImage24(QImage &img, QDataStream &s, PCXHEADER &header)
             b_buf[x] = qBlue(rgb);
         }
 
-        writeLine(s, r_buf);
-        writeLine(s, g_buf);
-        writeLine(s, b_buf);
+        if (!writeLine(s, r_buf)) {
+            return false;
+        }
+        if (!writeLine(s, g_buf)) {
+            return false;
+        }
+        if (!writeLine(s, b_buf)) {
+            return false;
+        }
     }
+
+    return true;
 }
 
 PCXHandler::PCXHandler()
@@ -588,46 +662,30 @@ bool PCXHandler::read(QImage *outImage)
 
     s >> header;
 
-    if (header.Manufacturer != 10 || s.atEnd()) {
+    if (header.Manufacturer != 10 || header.BytesPerLine == 0 || s.atEnd()) {
         return false;
     }
 
-    //   int w = header.width();
-    //   int h = header.height();
-
-    //   qDebug() << "Manufacturer: " << header.Manufacturer;
-    //   qDebug() << "Version: " << header.Version;
-    //   qDebug() << "Encoding: " << header.Encoding;
-    //   qDebug() << "Bpp: " << header.Bpp;
-    //   qDebug() << "Width: " << w;
-    //   qDebug() << "Height: " << h;
-    //   qDebug() << "Window: " << header.XMin << "," << header.XMax << ","
-    //                  << header.YMin << "," << header.YMax << endl;
-    //   qDebug() << "BytesPerLine: " << header.BytesPerLine;
-    //   qDebug() << "NPlanes: " << header.NPlanes;
-
+    auto ok = false;
     QImage img;
-
     if (header.Bpp == 1 && header.NPlanes == 1) {
-        readImage1(img, s, header);
+        ok = readImage1(img, s, header);
     } else if (header.Bpp == 1 && header.NPlanes == 4) {
-        readImage4(img, s, header);
+        ok = readImage4(img, s, header);
     } else if (header.Bpp == 8 && header.NPlanes == 1) {
-        readImage8(img, s, header);
+        ok = readImage8(img, s, header);
     } else if (header.Bpp == 8 && header.NPlanes == 3) {
-        readImage24(img, s, header);
+        ok = readImage24(img, s, header);
     }
 
-    //   qDebug() << "Image Bytes: " << img.numBytes();
-    //   qDebug() << "Image Bytes Per Line: " << img.bytesPerLine();
-    //   qDebug() << "Image Depth: " << img.depth();
-
-    if (!img.isNull()) {
-        *outImage = img;
-        return true;
-    } else {
+    if (img.isNull() || !ok) {
         return false;
     }
+
+    img.setDotsPerMeterX(qRound(header.HDpi / 25.4 * 1000));
+    img.setDotsPerMeterY(qRound(header.YDpi / 25.4 * 1000));
+    *outImage = img;
+    return true;
 }
 
 bool PCXHandler::write(const QImage &image)
@@ -644,12 +702,6 @@ bool PCXHandler::write(const QImage &image)
         return false;
     }
 
-    //   qDebug() << "Width: " << w;
-    //   qDebug() << "Height: " << h;
-    //   qDebug() << "Depth: " << img.depth();
-    //   qDebug() << "BytesPerLine: " << img.bytesPerLine();
-    //   qDebug() << "Color Count: " << img.colorCount();
-
     PCXHEADER header;
 
     header.Manufacturer = 10;
@@ -659,22 +711,23 @@ bool PCXHandler::write(const QImage &image)
     header.YMin = 0;
     header.XMax = w - 1;
     header.YMax = h - 1;
-    header.HDpi = 300;
-    header.YDpi = 300;
+    header.HDpi = qRound(image.dotsPerMeterX() * 25.4 / 1000);
+    header.YDpi = qRound(image.dotsPerMeterY() * 25.4 / 1000);
     header.Reserved = 0;
     header.PaletteInfo = 1;
 
+    auto ok = false;
     if (img.depth() == 1) {
-        writeImage1(img, s, header);
+        ok = writeImage1(img, s, header);
     } else if (img.depth() == 8 && img.colorCount() <= 16) {
-        writeImage4(img, s, header);
+        ok = writeImage4(img, s, header);
     } else if (img.depth() == 8) {
-        writeImage8(img, s, header);
-    } else if (img.depth() == 32) {
-        writeImage24(img, s, header);
+        ok = writeImage8(img, s, header);
+    } else if (img.depth() >= 24) {
+        ok = writeImage24(img, s, header);
     }
 
-    return true;
+    return ok;
 }
 
 bool PCXHandler::canRead(QIODevice *device)

src/imageformats/psd.cpp

@@ -9,8 +9,8 @@
 */
 
 /*
- * This code is based on Thacher Ulrich PSD loading code released
- * into the public domain. See: http://tulrich.com/geekstuff/
+ * The early version of this code was based on Thacher Ulrich PSD loading code
+ * released into the public domain. See: http://tulrich.com/geekstuff/
  */
 
 /*
@@ -733,9 +733,9 @@ static QImage::Format imageFormat(const PSDHeader &header, bool alpha)
     switch(header.color_mode) {
     case CM_RGB:
         if (header.depth == 16 || header.depth == 32)
-            format = header.channel_count < 4 || !alpha ? QImage::Format_RGBX64 : QImage::Format_RGBA64;
+            format = header.channel_count < 4 || !alpha ? QImage::Format_RGBX64 : QImage::Format_RGBA64_Premultiplied;
         else
-            format = header.channel_count < 4 || !alpha ? QImage::Format_RGB888 : QImage::Format_RGBA8888;
+            format = header.channel_count < 4 || !alpha ? QImage::Format_RGB888 : QImage::Format_RGBA8888_Premultiplied;
         break;
     case CM_MULTICHANNEL:       // Treat MCH as CMYK (number of channel check is done in IsSupported())
     case CM_CMYK:               // Photoshop supports CMYK/MCH 8-bits and 16-bits only
@@ -814,7 +814,7 @@ inline void planarToChunchy(uchar *target, const char *source, qint32 width, qin
     auto s = reinterpret_cast<const T*>(source);
     auto t = reinterpret_cast<T*>(target);
     for (qint32 x = 0; x < width; ++x) {
-        t[x*cn+c] = xchg(s[x]);
+        t[x * cn + c] = xchg(s[x]);
     }
 }
 
@@ -826,7 +826,44 @@ inline void planarToChunchyFloat(uchar *target, const char *source, qint32 width
     for (qint32 x = 0; x < width; ++x) {
         auto tmp = xchg(s[x]);
         auto ftmp = (*reinterpret_cast<float*>(&tmp) - double(min)) / (double(max) - double(min));
-        t[x*cn+c] = quint16(std::min(ftmp * std::numeric_limits<quint16>::max() + 0.5, double(std::numeric_limits<quint16>::max())));
+        t[x * cn + c] = quint16(std::min(ftmp * std::numeric_limits<quint16>::max() + 0.5, double(std::numeric_limits<quint16>::max())));
+    }
+}
+
+enum class PremulConversion {
+    PS2P, // Photoshop premul to qimage premul (required by RGB)
+    PS2A, // Photoshop premul to unassociated alpha (required by RGB, CMYK and L* components of LAB)
+    PSLab2A // Photoshop premul to unassociated alpha (required by a* and b* components of LAB)
+};
+
+template<class T>
+inline void premulConversion(char *stride, qint32 width, qint32 ac, qint32 cn, const PremulConversion &conv)
+{
+    auto s = reinterpret_cast<T *>(stride);
+    auto max = qint64(std::numeric_limits<T>::max());
+
+    for (qint32 c = 0; c < ac; ++c) {
+        if (conv == PremulConversion::PS2P) {
+            for (qint32 x = 0; x < width; ++x) {
+                auto xcn = x * cn;
+                auto alpha = *(s + xcn + ac);
+                *(s + xcn + c) = *(s + xcn + c) + alpha - max;
+            }
+        } else if (conv == PremulConversion::PS2A || (conv == PremulConversion::PSLab2A && c == 0)) {
+            for (qint32 x = 0; x < width; ++x) {
+                auto xcn = x * cn;
+                auto alpha = *(s + xcn + ac);
+                if (alpha > 0)
+                    *(s + xcn + c) = ((*(s + xcn + c) + alpha - max) * max + alpha / 2) / alpha;
+            }
+        } else if (conv == PremulConversion::PSLab2A) {
+            for (qint32 x = 0; x < width; ++x) {
+                auto xcn = x * cn;
+                auto alpha = *(s + xcn + ac);
+                if (alpha > 0)
+                    *(s + xcn + c) = ((*(s + xcn + c) + (alpha - max + 1) / 2) * max + alpha / 2) / alpha;
+            }
+        }
     }
 }
 
@@ -839,6 +876,18 @@ inline void monoInvert(uchar *target, const char* source, qint32 bytes)
     }
 }
 
+template<class T>
+inline void rawChannelsCopy(uchar *target, qint32 targetChannels, const char *source, qint32 sourceChannels, qint32 width)
+{
+    auto s = reinterpret_cast<const T *>(source);
+    auto t = reinterpret_cast<T *>(target);
+    for (qint32 c = 0, cs = std::min(targetChannels, sourceChannels); c < cs; ++c) {
+        for (qint32 x = 0; x < width; ++x) {
+            t[x * targetChannels + c] = s[x * sourceChannels + c];
+        }
+    }
+}
+
 template<class T>
 inline void cmykToRgb(uchar *target, qint32 targetChannels, const char *source, qint32 sourceChannels, qint32 width, bool alpha = false)
 {
@@ -1060,7 +1109,15 @@ static bool LoadPSD(QDataStream &stream, const PSDHeader &header, QImage &img)
     QByteArray rawStride;
     rawStride.resize(raw_count);
 
-    if (header.color_mode == CM_CMYK || header.color_mode == CM_LABCOLOR || header.color_mode == CM_MULTICHANNEL) {
+    // clang-format off
+    // checks the need of color conversion (that requires random access to the image)
+    auto randomAccess = (header.color_mode == CM_CMYK) ||
+        (header.color_mode == CM_LABCOLOR) ||
+        (header.color_mode == CM_MULTICHANNEL) ||
+        (header.color_mode != CM_INDEXED && img.hasAlphaChannel());
+    // clang-format on
+
+    if (randomAccess) {
         // In order to make a colorspace transformation, we need all channels of a scanline
         QByteArray psdScanline;
         psdScanline.resize(qsizetype(header.width * std::min(header.depth, quint16(16)) * header.channel_count + 7) / 8);
@@ -1080,31 +1137,56 @@ static bool LoadPSD(QDataStream &stream, const PSDHeader &header, QImage &img)
                 auto scanLine = reinterpret_cast<unsigned char*>(psdScanline.data());
                 if (header.depth == 8) {
                     planarToChunchy<quint8>(scanLine, rawStride.data(), header.width, c, header.channel_count);
-                }
-                else if (header.depth == 16) {
+                } else if (header.depth == 16) {
                     planarToChunchy<quint16>(scanLine, rawStride.data(), header.width, c, header.channel_count);
-                }
-                else if (header.depth == 32) { // Not currently used
+                } else if (header.depth == 32) {
                     planarToChunchyFloat<quint32>(scanLine, rawStride.data(), header.width, c, header.channel_count);
                 }
             }
 
+            // Convert premultiplied data to unassociated data
+            if (img.hasAlphaChannel()) {
+                if (header.color_mode == CM_CMYK) {
+                    if (header.depth == 8)
+                        premulConversion<quint8>(psdScanline.data(), header.width, 4, header.channel_count, PremulConversion::PS2A);
+                    else if (header.depth == 16)
+                        premulConversion<quint16>(psdScanline.data(), header.width, 4, header.channel_count, PremulConversion::PS2A);
+                }
+                if (header.color_mode == CM_LABCOLOR) {
+                    if (header.depth == 8)
+                        premulConversion<quint8>(psdScanline.data(), header.width, 3, header.channel_count, PremulConversion::PSLab2A);
+                    else if (header.depth == 16)
+                        premulConversion<quint16>(psdScanline.data(), header.width, 3, header.channel_count, PremulConversion::PSLab2A);
+                }
+                if (header.color_mode == CM_RGB) {
+                    if (header.depth == 8)
+                        premulConversion<quint8>(psdScanline.data(), header.width, 3, header.channel_count, PremulConversion::PS2P);
+                    else if (header.depth == 16 || header.depth == 32)
+                        premulConversion<quint16>(psdScanline.data(), header.width, 3, header.channel_count, PremulConversion::PS2P);
+                }
+            }
+
             // Conversion to RGB
             if (header.color_mode == CM_CMYK || header.color_mode == CM_MULTICHANNEL) {
                 if (header.depth == 8)
                     cmykToRgb<quint8>(img.scanLine(y), imgChannels, psdScanline.data(), header.channel_count, header.width, alpha);
-                else
+                else if (header.depth == 16)
                     cmykToRgb<quint16>(img.scanLine(y), imgChannels, psdScanline.data(), header.channel_count, header.width, alpha);
             }
             if (header.color_mode == CM_LABCOLOR) {
                 if (header.depth == 8)
                     labToRgb<quint8>(img.scanLine(y), imgChannels, psdScanline.data(), header.channel_count, header.width, alpha);
-                else
+                else if (header.depth == 16)
                     labToRgb<quint16>(img.scanLine(y), imgChannels, psdScanline.data(), header.channel_count, header.width, alpha);
             }
+            if (header.color_mode == CM_RGB) {
+                if (header.depth == 8)
+                    rawChannelsCopy<quint8>(img.scanLine(y), imgChannels, psdScanline.data(), header.channel_count, header.width);
+                else if (header.depth == 16 || header.depth == 32)
+                    rawChannelsCopy<quint16>(img.scanLine(y), imgChannels, psdScanline.data(), header.channel_count, header.width);
+            }
         }
-    }
-    else {
+    } else {
         // Linear read (no position jumps): optimized code usable only for the colorspaces supported by QImage
         for (qint32 c = 0; c < channel_num; ++c) {
             for (qint32 y = 0, h = header.height; y < h; ++y) {
@@ -1115,16 +1197,13 @@ static bool LoadPSD(QDataStream &stream, const PSDHeader &header, QImage &img)
                 }
 
                 auto scanLine = img.scanLine(y);
-                if (header.depth == 1) {        // Bitmap
+                if (header.depth == 1) { // Bitmap
                     monoInvert(scanLine, rawStride.data(), std::min(rawStride.size(), img.bytesPerLine()));
-                }
-                else if (header.depth == 8) {   // 8-bits images: Indexed, Grayscale, RGB/RGBA
+                } else if (header.depth == 8) { // 8-bits images: Indexed, Grayscale, RGB/RGBA
                     planarToChunchy<quint8>(scanLine, rawStride.data(), header.width, c, imgChannels);
-                }
-                else if (header.depth == 16) {  // 16-bits integer images: Grayscale, RGB/RGBA
+                } else if (header.depth == 16) { // 16-bits integer images: Grayscale, RGB/RGBA
                     planarToChunchy<quint16>(scanLine, rawStride.data(), header.width, c, imgChannels);
-                }
-                else if (header.depth == 32) {  // 32-bits float images: Grayscale, RGB/RGBA (coverted to equivalent integer 16-bits)
+                } else if (header.depth == 32) { // 32-bits float images: Grayscale, RGB/RGBA (coverted to equivalent integer 16-bits)
                     planarToChunchyFloat<quint32>(scanLine, rawStride.data(), header.width, c, imgChannels);
                 }
             }
@@ -1267,6 +1346,9 @@ bool PSDHandler::canRead(QIODevice *device)
         if (header.color_mode == CM_CMYK || header.color_mode == CM_LABCOLOR || header.color_mode == CM_MULTICHANNEL) {
             return false;
         }
+        if (header.color_mode == CM_RGB && header.channel_count > 3) {
+            return false; // supposing extra channel as alpha
+        }
     }
 
     return IsSupported(header);

src/imageformats/rgb.cpp

@@ -672,11 +672,16 @@ bool SGIImage::writeImage(const QImage &image)
         _dim = 3, _zsize = 3;
     }
 
-    if (img.format() == QImage::Format_ARGB32) {
+    auto hasAlpha = img.hasAlphaChannel();
+    if (hasAlpha) {
         _dim = 3, _zsize++;
     }
 
-    img = img.convertToFormat(QImage::Format_RGB32);
+    if (hasAlpha && img.format() != QImage::Format_ARGB32) {
+        img = img.convertToFormat(QImage::Format_ARGB32);
+    } else if (!hasAlpha && img.format() != QImage::Format_RGB32) {
+        img = img.convertToFormat(QImage::Format_RGB32);
+    }
     if (img.isNull()) {
         //         qDebug() << "can't convert image to depth 32";
         return false;
@@ -685,7 +690,7 @@ bool SGIImage::writeImage(const QImage &image)
     const int w = img.width();
     const int h = img.height();
 
-    if (w > 65536 || h > 65536) {
+    if (w > 65535 || h > 65535) {
         return false;
     }
 
@@ -712,12 +717,6 @@ bool SGIImage::writeImage(const QImage &image)
         rle_size += _rlevector[i]->size();
     }
 
-    //     qDebug() << "minimum intensity: " << _pixmin;
-    //     qDebug() << "maximum intensity: " << _pixmax;
-    //     qDebug() << "saved scanlines: " << _numrows - _rlemap.size();
-    //     qDebug() << "total savings: " << (verbatim_size - rle_size) << " bytes";
-    //     qDebug() << "compression: " << (rle_size * 100.0 / verbatim_size) << '%';
-
     if (verbatim_size <= rle_size) {
         writeVerbatim(img);
     } else {

src/imageformats/tga.cpp

@@ -428,8 +428,17 @@ bool TGAHandler::write(const QImage &image)
     QDataStream s(device());
     s.setByteOrder(QDataStream::LittleEndian);
 
-    const QImage &img = image;
-    const bool hasAlpha = (img.format() == QImage::Format_ARGB32);
+    QImage img(image);
+    const bool hasAlpha = img.hasAlphaChannel();
+    if (hasAlpha && img.format() != QImage::Format_ARGB32) {
+        img = img.convertToFormat(QImage::Format_ARGB32);
+    } else if (!hasAlpha && img.format() != QImage::Format_RGB32) {
+        img = img.convertToFormat(QImage::Format_RGB32);
+    }
+    if (img.isNull()) {
+        qDebug() << "TGAHandler::write: image conversion to 32 bits failed!";
+        return false;
+    }
     static constexpr quint8 originTopLeft = TGA_ORIGIN_UPPER + TGA_ORIGIN_LEFT; // 0x20
     static constexpr quint8 alphaChannel8Bits = 0x08;
 
@@ -444,8 +453,9 @@ bool TGAHandler::write(const QImage &image)
     s << quint8(hasAlpha ? originTopLeft + alphaChannel8Bits : originTopLeft);   // top left image (0x20) + 8 bit alpha (0x8)
 
     for (int y = 0; y < img.height(); y++) {
+        auto ptr = reinterpret_cast<QRgb *>(img.scanLine(y));
         for (int x = 0; x < img.width(); x++) {
-            const QRgb color = img.pixel(x, y);
+            auto color = *(ptr + x);
             s << quint8(qBlue(color));
             s << quint8(qGreen(color));
             s << quint8(qRed(color));