void PNGImageDecoder::headerAvailable()
{
png_structp png = m_reader->pngPtr();
png_infop info = m_reader->infoPtr();
png_uint_32 width = png_get_image_width(png, info);
png_uint_32 height = png_get_image_height(png, info);
// Protect against large PNGs. See http://bugzil.la/251381 for more details.
const unsigned long maxPNGSize = 1000000UL;
if (width > maxPNGSize || height > maxPNGSize) {
longjmp(JMPBUF(png), 1);
return;
}
// Set the image size now that the image header is available.
if (!setSize(width, height)) {
longjmp(JMPBUF(png), 1);
return;
}
int bitDepth, colorType, interlaceType, compressionType, filterType, channels;
png_get_IHDR(png, info, &width, &height, &bitDepth, &colorType, &interlaceType, &compressionType, &filterType);
// The options we set here match what Mozilla does.
// Expand to ensure we use 24-bit for RGB and 32-bit for RGBA.
if (colorType == PNG_COLOR_TYPE_PALETTE || (colorType == PNG_COLOR_TYPE_GRAY && bitDepth < 8))
png_set_expand(png);
png_bytep trns = 0;
int trnsCount = 0;
if (png_get_valid(png, info, PNG_INFO_tRNS)) {
png_get_tRNS(png, info, &trns, &trnsCount, 0);
png_set_expand(png);
}
if (bitDepth == 16)
png_set_strip_16(png);
if (colorType == PNG_COLOR_TYPE_GRAY || colorType == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(png);
#if USE(QCMSLIB)
if ((colorType & PNG_COLOR_MASK_COLOR) && !m_ignoreGammaAndColorProfile) {
// We only support color profiles for color PALETTE and RGB[A] PNG. Supporting
// color profiles for gray-scale images is slightly tricky, at least using the
// CoreGraphics ICC library, because we expand gray-scale images to RGB but we
// do not similarly transform the color profile. We'd either need to transform
// the color profile or we'd need to decode into a gray-scale image buffer and
// hand that to CoreGraphics.
bool sRGB = false;
ColorProfile colorProfile;
getColorProfile(png, info, colorProfile, sRGB);
bool imageHasAlpha = (colorType & PNG_COLOR_MASK_ALPHA) || trnsCount;
m_reader->createColorTransform(colorProfile, imageHasAlpha, sRGB);
m_hasColorProfile = !!m_reader->colorTransform();
}
#endif
if (!m_hasColorProfile) {
// Deal with gamma and keep it under our control.
const double inverseGamma = 0.45455;
const double defaultGamma = 2.2;
double gamma;
if (!m_ignoreGammaAndColorProfile && png_get_gAMA(png, info, &gamma)) {
const double maxGamma = 21474.83;
if ((gamma <= 0.0) || (gamma > maxGamma)) {
gamma = inverseGamma;
png_set_gAMA(png, info, gamma);
}
png_set_gamma(png, defaultGamma, gamma);
} else {
png_set_gamma(png, defaultGamma, inverseGamma);
}
}
// Tell libpng to send us rows for interlaced pngs.
if (interlaceType == PNG_INTERLACE_ADAM7)
png_set_interlace_handling(png);
// Update our info now.
png_read_update_info(png, info);
channels = png_get_channels(png, info);
ASSERT(channels == 3 || channels == 4);
m_reader->setHasAlpha(channels == 4);
if (m_reader->decodingSizeOnly()) {
// If we only needed the size, halt the reader.
#if PNG_LIBPNG_VER_MAJOR > 1 || (PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 5)
// '0' argument to png_process_data_pause means: Do not cache unprocessed data.
m_reader->setReadOffset(m_reader->currentBufferSize() - png_process_data_pause(png, 0));
#else
m_reader->setReadOffset(m_reader->currentBufferSize() - png->buffer_size);
png->buffer_size = 0;
#endif
}
}
ZLColorOption& FBOptions::regularTextColorOption() {
return *(getColorProfile().RegularTextColorOption);
}
ZLColorOption &FBOptions::colorOption(const std::string &style) {
// AppLog("colorOption %s",style.c_str());
return getColorProfile().colorOption(style);
}
ZLColorOption& FBOptions::backgroundColorOption() {
return *(getColorProfile().BackgroundColorOption);
}
