From 73b88fccedfe3912649d119bedf8490ab6c41812 Mon Sep 17 00:00:00 2001 From: Giuseppe D'Angelo Date: Tue, 17 Sep 2013 22:22:30 +0200 Subject: PNG: properly handle 1bpp greyscale images with alpha PNG allows 1bpp greyscale images (PNG_COLOR_TYPE_GRAY) to have an alpha key; so even in this case we need to inquiry if the image has a transparency, and if so modify the color table of the monochrome image accordingly. Task-number: QTBUG-33503 Change-Id: Iab07c8f95ac8865269c48816e222645cdcb6bbc1 Reviewed-by: Nicolas Arnaud-Cormos Reviewed-by: aavit --- src/gui/image/qpnghandler.cpp | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'src/gui') diff --git a/src/gui/image/qpnghandler.cpp b/src/gui/image/qpnghandler.cpp index 4b016782b1..3ee9e200de 100644 --- a/src/gui/image/qpnghandler.cpp +++ b/src/gui/image/qpnghandler.cpp @@ -281,6 +281,15 @@ void setup_qt(QImage& image, png_structp png_ptr, png_infop info_ptr, QSize scal image.setColorCount(2); image.setColor(1, qRgb(0,0,0)); image.setColor(0, qRgb(255,255,255)); + if (png_get_tRNS(png_ptr, info_ptr, &trans_alpha, &num_trans, &trans_color_p) && trans_color_p) { + const int g = trans_color_p->gray; + // the image has white in the first position of the color table, + // black in the second. g is 0 for black, 1 for white. + if (g == 0) + image.setColor(1, qRgba(0, 0, 0, 0)); + else if (g == 1) + image.setColor(0, qRgba(255, 255, 255, 0)); + } } else if (bit_depth == 16 && png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) { png_set_expand(png_ptr); png_set_strip_16(png_ptr); -- cgit v1.2.3