From 1192c463db34e3f69be4d9ef976246ce265143a3 Mon Sep 17 00:00:00 2001 From: Alexandra Cherdantseva Date: Fri, 7 Sep 2018 13:07:35 +0300 Subject: QImageWriter/QPNGHandler: Quality option should be CompressionRatio Wrong option was used to set zlib compression level for png setCompression with negative value uses default compression setCompression with value between 0-100 converts to zlib compression level 0-9 setCompression with positive value overrides Quality option Change-Id: Ic4b048a1e30d6940019c2a00a6c24d0c11e3f821 Reviewed-by: Alexandra Cherdantseva Reviewed-by: Eirik Aavitsland --- src/gui/image/qpnghandler.cpp | 50 +++++++++++++++++++++++++++---------------- 1 file changed, 31 insertions(+), 19 deletions(-) (limited to 'src/gui') diff --git a/src/gui/image/qpnghandler.cpp b/src/gui/image/qpnghandler.cpp index 242d8cd63b..13129e214b 100644 --- a/src/gui/image/qpnghandler.cpp +++ b/src/gui/image/qpnghandler.cpp @@ -99,12 +99,13 @@ public: }; QPngHandlerPrivate(QPngHandler *qq) - : gamma(0.0), fileGamma(0.0), quality(2), png_ptr(0), info_ptr(0), end_info(0), state(Ready), q(qq) + : gamma(0.0), fileGamma(0.0), quality(50), compression(50), png_ptr(0), info_ptr(0), end_info(0), state(Ready), q(qq) { } float gamma; float fileGamma; - int quality; + int quality; // quality is used for backward compatibility, maps to compression + int compression; QString description; QSize scaledSize; QStringList readTexts; @@ -161,11 +162,11 @@ public: void setGamma(float); bool writeImage(const QImage& img, int x, int y); - bool writeImage(const QImage& img, volatile int quality, const QString &description, int x, int y); + bool writeImage(const QImage& img, volatile int compression_in, const QString &description, int x, int y); bool writeImage(const QImage& img) { return writeImage(img, 0, 0); } - bool writeImage(const QImage& img, int quality, const QString &description) - { return writeImage(img, quality, description, 0, 0); } + bool writeImage(const QImage& img, int compression, const QString &description) + { return writeImage(img, compression, description, 0, 0); } QIODevice* device() { return dev; } @@ -814,7 +815,7 @@ bool QPNGImageWriter::writeImage(const QImage& image, int off_x, int off_y) return writeImage(image, -1, QString(), off_x, off_y); } -bool QPNGImageWriter::writeImage(const QImage& image, volatile int quality_in, const QString &description, +bool QPNGImageWriter::writeImage(const QImage& image, volatile int compression_in, const QString &description, int off_x_in, int off_y_in) { QPoint offset = image.offset(); @@ -842,13 +843,13 @@ bool QPNGImageWriter::writeImage(const QImage& image, volatile int quality_in, c return false; } - int quality = quality_in; - if (quality >= 0) { - if (quality > 9) { - qWarning("PNG: Quality %d out of range", quality); - quality = 9; + int compression = compression_in; + if (compression >= 0) { + if (compression > 9) { + qWarning("PNG: Compression %d out of range", compression); + compression = 9; } - png_set_compression_level(png_ptr, quality); + png_set_compression_level(png_ptr, compression); } png_set_write_fn(png_ptr, (void*)this, qpiw_write_fn, qpiw_flush_fn); @@ -1067,15 +1068,21 @@ bool QPNGImageWriter::writeImage(const QImage& image, volatile int quality_in, c } static bool write_png_image(const QImage &image, QIODevice *device, - int quality, float gamma, const QString &description) + int compression, int quality, float gamma, const QString &description) { + // quality is used for backward compatibility, maps to compression + QPNGImageWriter writer(device); - if (quality >= 0) { - quality = qMin(quality, 100); - quality = (100-quality) * 9 / 91; // map [0,100] -> [9,0] - } + if (compression >= 0) + compression = qMin(compression, 100); + else if (quality >= 0) + compression = 100 - qMin(quality, 100); + + if (compression >= 0) + compression = (compression * 9) / 91; // map [0,100] -> [0,9] + writer.setGamma(gamma); - return writer.writeImage(image, quality, description); + return writer.writeImage(image, compression, description); } QPngHandler::QPngHandler() @@ -1122,7 +1129,7 @@ bool QPngHandler::read(QImage *image) bool QPngHandler::write(const QImage &image) { - return write_png_image(image, device(), d->quality, d->gamma, d->description); + return write_png_image(image, device(), d->compression, d->quality, d->gamma, d->description); } bool QPngHandler::supportsOption(ImageOption option) const @@ -1131,6 +1138,7 @@ bool QPngHandler::supportsOption(ImageOption option) const || option == Description || option == ImageFormat || option == Quality + || option == CompressionRatio || option == Size || option == ScaledSize; } @@ -1146,6 +1154,8 @@ QVariant QPngHandler::option(ImageOption option) const return d->gamma == 0.0 ? d->fileGamma : d->gamma; else if (option == Quality) return d->quality; + else if (option == CompressionRatio) + return d->compression; else if (option == Description) return d->description; else if (option == Size) @@ -1164,6 +1174,8 @@ void QPngHandler::setOption(ImageOption option, const QVariant &value) d->gamma = value.toFloat(); else if (option == Quality) d->quality = value.toInt(); + else if (option == CompressionRatio) + d->compression = value.toInt(); else if (option == Description) d->description = value.toString(); else if (option == ScaledSize) -- cgit v1.2.3