PNG to MNG, persistence issue

Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
Post Reply
Yolteotl
Posts: 1
Joined: 2018-03-14T13:25:42-07:00
Authentication code: 1152

PNG to MNG, persistence issue

Post by Yolteotl » 2018-03-14T13:37:14-07:00

Hi everyone,

I'm currently trying to generate a MNG with ImageMagick (Ubuntu 14.04 base version, 6.7.7-10). Basically, I have a set of PNG showing an animated logo, it has lot of alpha in it and since my software is using Qt, I have not a lot of other options to create an animated logo...

If I use animate command with PNGs directly and using dispose option : animate -dispose Background *png. The result is perfect.
However, if I use the convert command (convert -dispose Background *png output.mng), the firsts images are never cleaned, and after 150 images stacking, the result is more than ugly. (little black shadow becomes a huge border...)

I tried several options, but I did not find a proper way to do it.
What I noticed, using identify (identify -verbose test.mng | grep Dispose), that all images, except last, have a Dispose field set at None :

Dispose: None
Dispose: None
Dispose: None
Dispose: None
...
Dispose: None
Dispose: None
Dispose: Background

Not sure where to go from it. Any idea?

Thanks!

Edit: Going a bit further. I tried to convert the file in MIFF format, and this time, the images are saved correctly, identify returns Dispose: Background and animate shows it correctly. So it looks to me that there might be an issue there.

Post Reply