Page 1 of 1

possible bug grayscale psd IM 6.6.4.0

Posted: 2010-09-10T10:25:47-07:00
by fmw42
IM 6.6.4.0 Q16 (hdri) Mac OSX Tiger

I created the following grayscale PSD image with two layers, one for grayscale zelda and one for grayscale lena, on a transparent background. The image looks fine in Photoshop.

When I separate the layers, with the following, I get cyan colored layers. Is this correct? Note there is an error message about out of range tRNS chunk.

PSD:
http://www.fmwconcepts.com/misc_tests/p ... nsback.psd

Resulting layers with:


convert test3_gray_transback.psd test3_gray_transback_%d.png
convert: tRNS chunk has out-of-range samples for bit_depth `test3_gray_transback_0.png' @ warning/png.c/PNGWarningHandler/1503.

Image

Image

Image

Re: possible bug grayscale psd IM 6.6.4.0

Posted: 2010-09-10T11:30:20-07:00
by Drarakel
fmw42 wrote:Note there is an error message about out of range tRNS chunk.
You can avoid that warning by adding "-type TrueColorMatte". (IM probably tries to write the composite layer as palette+tRNS, fails, and reverts to grayscale+alpha.)
The other error of course stays the same...

Re: possible bug grayscale psd IM 6.6.4.0

Posted: 2010-09-10T17:14:12-07:00
by fmw42
Thanks that gets rid of the error message, though I would not think that should be necessary. However, it does not cure the cyan colored frames/layers.

Re: possible bug grayscale psd IM 6.6.4.0

Posted: 2010-09-16T11:51:53-07:00
by fmw42
Doing a little testing, it appears that layers 1 and 2 are setting the green and blue channels to full white and keeping the red slightly modified, so that the result is cyan. It seems to be similar but not exactly the same as:

convert zelda3.png -channel gb -evaluate set 100% -channel rgb zelda3_tmp.png