Hi Aaron,
I'm working on your ICC profile patches but this one made me wonder what
happens with monochrome scans, i.e. grayscale with a bit depth of one.
If that works fine, I'll push your patches with two fixes after merging
against master.
Aaron Muir Hamilton writes:
> If the ICC profile added does not match the colour format of the
> image, libpng will abort. This can leave the scanner motors in an
> incorrect state and possibly cause permanent damage.
> ---
> frontend/scanimage.c | 22 +++++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/frontend/scanimage.c b/frontend/scanimage.c
> index 0f71422c..74546763 100644
> --- a/frontend/scanimage.c
> +++ b/frontend/scanimage.c
> @@ -1208,7 +1208,27 @@ write_png_header (SANE_Frame format, int width, int
> height, int depth, const cha
> icc_buffer = sanei_load_icc_profile(icc_profile, &icc_size);
> if (icc_size > 0)
> {
> - png_set_iCCP(*png_ptr, *info_ptr, basename(icc_profile),
> PNG_COMPRESSION_TYPE_BASE, icc_buffer, icc_size);
> + /* libpng will abort if the profile and image colour spaces do not
> match*/
> + /* The data colour space field is at bytes 16 to 20 in an ICC profile
> */
> + /* see: ICC.1:2010 ยง 7.2.6 */
> + int is_gray_profile = strncmp(icc_buffer + 16, "GRAY", 4) == 0;
> + int is_rgb_profile = strncmp(icc_buffer + 16, "RGB ", 4) == 0;
> + if ((is_gray_profile && color_type == PNG_COLOR_TYPE_GRAY) ||
> + (is_rgb_profile && color_type == PNG_COLOR_TYPE_RGB))
> + {
> + png_set_iCCP(*png_ptr, *info_ptr, basename(icc_profile),
> PNG_COMPRESSION_TYPE_BASE, icc_buffer, icc_size);
> + }
> + else
> + {
> + if (is_gray_profile)
> + {
> + fprintf(stderr, "Ignoring 'GRAY' space ICC profile because
> the image is RGB.\n");
> + }
> + if (is_rgb_profile)
> + {
> + fprintf(stderr, "Ignoring 'RGB ' space ICC profile because
> the image is Grayscale.\n");
> + }
> + }
> free(icc_buffer);
> }
> }
> --
> 2.12.2
--
Olaf Meeuwissen, LPIC-2 FSF Associate Member since 2004-01-27
GnuPG key: F84A2DD9/B3C0 2F47 EA19 64F4 9F13 F43E B8A4 A88A F84A 2DD9
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