vcl/source/filter/png/PngImageReader.cxx | 37 +++++++++++++++++++++++++++++--
1 file changed, 35 insertions(+), 2 deletions(-)
New commits:
commit 12eac05c8088cefadace2629efce5473212662eb
Author: Luboš Luňák <l.lu...@collabora.com>
AuthorDate: Fri Mar 5 21:45:11 2021 +0100
Commit: Luboš Luňák <l.lu...@collabora.com>
CommitDate: Fri Mar 12 15:36:05 2021 +0100
make PngImageReader read grayscale images as 8bpp, not 24bpp
Grayscale is still a direct-color format, so it can save memory
while not being slow (well, at least with Skia I made sure it's
fast). PNGReader also reads grayscale images this way.
Change-Id: I896f9901aca4defc8263fdcea6d2bebd574d1e8a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/112040
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <qui...@gmail.com>
Reviewed-by: Luboš Luňák <l.lu...@collabora.com>
diff --git a/vcl/source/filter/png/PngImageReader.cxx
b/vcl/source/filter/png/PngImageReader.cxx
index a510c6704686..3351e314b3fe 100644
--- a/vcl/source/filter/png/PngImageReader.cxx
+++ b/vcl/source/filter/png/PngImageReader.cxx
@@ -134,7 +134,9 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
if (bitDepth < 8)
png_set_packing(pPng);
- if (colorType == PNG_COLOR_TYPE_GRAY || colorType ==
PNG_COLOR_TYPE_GRAY_ALPHA)
+ // Convert gray+alpha to RGBA, keep gray as gray.
+ if (colorType == PNG_COLOR_TYPE_GRAY_ALPHA
+ || (colorType == PNG_COLOR_TYPE_GRAY && png_get_valid(pPng, pInfo,
PNG_INFO_tRNS)))
{
png_set_gray_to_rgb(pPng);
}
@@ -154,7 +156,9 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
return false;
}
- if (bitDepth != 8 || (colorType != PNG_COLOR_TYPE_RGB && colorType !=
PNG_COLOR_TYPE_RGB_ALPHA))
+ if (bitDepth != 8
+ || (colorType != PNG_COLOR_TYPE_RGB && colorType !=
PNG_COLOR_TYPE_RGB_ALPHA
+ && colorType != PNG_COLOR_TYPE_GRAY))
{
png_destroy_read_struct(&pPng, &pInfo, nullptr);
return false;
@@ -299,6 +303,35 @@ bool reader(SvStream& rStream, BitmapEx& rBitmapEx, bool
bUseBitmap32)
rBitmapEx = BitmapEx(aBitmap, aBitmapAlpha);
}
}
+ else if (colorType == PNG_COLOR_TYPE_GRAY)
+ {
+ size_t aRowSizeBytes = png_get_rowbytes(pPng, pInfo);
+
+ aBitmap = Bitmap(Size(width, height), 8,
&Bitmap::GetGreyPalette(256));
+ aBitmap.Erase(COL_WHITE);
+ {
+ pWriteAccess = BitmapScopedWriteAccess(aBitmap);
+
+ aRows = std::vector<std::vector<png_byte>>(height);
+ for (auto& rRow : aRows)
+ rRow.resize(aRowSizeBytes, 0);
+
+ for (int pass = 0; pass < nNumberOfPasses; pass++)
+ {
+ for (png_uint_32 y = 0; y < height; y++)
+ {
+ Scanline pScanline = pWriteAccess->GetScanline(y);
+ png_bytep pRow = aRows[y].data();
+ png_read_row(pPng, pRow, nullptr);
+ size_t iColor = 0;
+ for (size_t i = 0; i < aRowSizeBytes; ++i)
+ pScanline[iColor++] = pRow[i];
+ }
+ }
+ pWriteAccess.reset();
+ }
+ rBitmapEx = BitmapEx(aBitmap);
+ }
}
png_read_end(pPng, pInfo);
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