gif to png; changing one color
Posted: 2010-07-04T03:07:44-07:00
Hi,
First of all, I am a relatively new user to ImageMagick, so I might be doing something wrong.
I am using: ImageMagick 6.6.2-9 2010-07-04 Q16 with OS X 10.6.2
I installed with MacPorts. No newer version of IM is available with MacPorts.
First, I tried to convert a gif to a png.
The gif has transparency. The resulting png has not: the transparent pixels became green.
I accidentally found a work around. This command gives the correct result:
Now, I want to change a single color:
It does not work either, all the 248,248,248 pixels become black 
So, are those problems bugs, or is it normal ?
a.gif:
a.png:
b.png:
First of all, I am a relatively new user to ImageMagick, so I might be doing something wrong.
I am using: ImageMagick 6.6.2-9 2010-07-04 Q16 with OS X 10.6.2
I installed with MacPorts. No newer version of IM is available with MacPorts.
First, I tried to convert a gif to a png.
Code: Select all
convert a.gif a.png
convert: tRNS chunk has out-of-range samples for bit_depth `a.png' @ warning/png.c/PNGWarningHandler/1457.
I accidentally found a work around. This command gives the correct result:
Code: Select all
convert a.gif -fill 'rgb(0,0,0)' -opaque 'rgb(0,0,0)' a2.png
Code: Select all
convert a2.png -opaque 'rgb(248,248,248)' -fill 'rgb(255,0,0)' b.png

So, are those problems bugs, or is it normal ?
a.gif:
a.png:
b.png: