I'm trying to use w3m to display image in emacs, however I saw that for some reasons it's unable to display correctly the png files that have a non-rgb colormap. Here is an example:
All the images are png:
- The first picture has been manually created using gimp, and
file gives me:
8-bit/color RGBA, non-interlaced. This image is nicely displayed.
- The second picture was generated by an export of a latex formula using org-mode, and
file gives me
4-bit colormap, non-interlaced, but you can also generate this kind of picture using gimp and setting the mode to
indexed colors. This image has a white background (why ?), and the conversion is very bad, like if imagemagick was used without any parameters to deal with the alpha channel
- The third one is like the second one, but exported into gimp, and saved directly without changing anything, and
file gives me the same thing:
4-bit colormap, non-interlaced. The question is why is the background color different?
- The last one is the same one as the last one, but saved from gimp using mode RGB, file gives me
8-bit/color RGBA, non-interlaced.
I though at the beginning that the problem was concerning imagemagick... But I tried to replace
convert in the path with a custom script that would write a new line in a log file during call, and this script is called only once the first time I load w3m, and the parameters given let me think that it's only to check if imagemagick supports PNG, but this function was not called later.
So here is my question:
1) why are
4-bit colormap (and maybe others) a problem?
2) how could I have a nice display for them?