diff options
author | dcommander <dcommander@3789f03b-4d11-0410-bbf8-ca57d06f2519> | 2011-09-08 23:54:40 +0000 |
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committer | dcommander <dcommander@3789f03b-4d11-0410-bbf8-ca57d06f2519> | 2011-09-08 23:54:40 +0000 |
commit | ce61a9dd8b021c6a6ca147c721af4f6886985e9a (patch) | |
tree | 2635f7aaa429868e7f8cebe0dbd9f3ce0bc4b23a /trunk/jdcolext.c | |
parent | 0c0340fe0ebb95acaaaf3122e12c454371573d5c (diff) |
When decompressing to a 4-byte RGB buffer, set the unused byte to 0xFF so it can be interpreted as an opaque alpha channel.
git-svn-id: https://libjpeg-turbo.svn.sourceforge.net/svnroot/libjpeg-turbo@699 3789f03b-4d11-0410-bbf8-ca57d06f2519
Diffstat (limited to 'trunk/jdcolext.c')
-rw-r--r-- | trunk/jdcolext.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/trunk/jdcolext.c b/trunk/jdcolext.c index d0ccca3..af7ea7e 100644 --- a/trunk/jdcolext.c +++ b/trunk/jdcolext.c @@ -54,6 +54,10 @@ ycc_rgb_convert_internal (j_decompress_ptr cinfo, y = GETJSAMPLE(inptr0[col]); cb = GETJSAMPLE(inptr1[col]); cr = GETJSAMPLE(inptr2[col]); + /* Initialize 4-byte pixels so the alpha channel will be opaque */ +#if RGB_PIXELSIZE == 4 + *(unsigned int *)outptr = 0xFFFFFFFF; +#endif /* Range-limiting is essential due to noise introduced by DCT losses. */ outptr[RGB_RED] = range_limit[y + Crrtab[cr]]; outptr[RGB_GREEN] = range_limit[y + @@ -86,6 +90,10 @@ gray_rgb_convert_internal (j_decompress_ptr cinfo, inptr = input_buf[0][input_row++]; outptr = *output_buf++; for (col = 0; col < num_cols; col++) { + /* Initialize 4-byte pixels so the alpha channel will be opaque */ +#if RGB_PIXELSIZE == 4 + *(unsigned int *)outptr = 0xFFFFFFFF; +#endif /* We can dispense with GETJSAMPLE() here */ outptr[RGB_RED] = outptr[RGB_GREEN] = outptr[RGB_BLUE] = inptr[col]; outptr += RGB_PIXELSIZE; |