Reported Display problems with oversized animated GIFs

[als]

Animated GIF files that are larger than my screen resolution are displayed sized down to fit the screen when opened in window mode, regardless of what fit mode is selected in the display options, as if "fit image to desktop" is selected. Switching to any other fit mode without closing and reloading the program will result in the image being shown just like it should for that fit mode (e.g. "do not fit anything" and the image will be displayed in it's original size). Same if "original size" (CTRL+H) is selected.

Inversely, in full-screen mode the image will always be displayed in it's original size, again ignoring the resizing options selected in the Full-screen/Slideshow settings and cutting off the oversized part of the image.

If an animated GIF is larger than the screen, the program does not show a scroll bar in window mode, and other methods of scrolling (e.g. page down button, mouse wheel) will load the next image instead (as it would with a not oversized image). This applies both to originally large files as well as to zoomed in small images.

I observed this on three different computers, with Windows XP as well as Windows 7, with IrfanView version 4.35.

Also, I'm not sure this qualifies as a bug, but when displaying an oversized animated GIF (but not with a zoomed in regular sized one), IrfanView generates quite considerable CPU load (constantly 30~50% on an outdated AMD AthlonXP with 2.28GHz and 1GB RAM and still 10~20% on a current laptop with this image, for example). Meanwhile the image quality for resizing animated GIFs appears to be not very good (there seems to be no resampling happening regardless of whether those options are selected).

[Mij]

Have you found a program that does handle automatic resizing of your large animated GIF correctly?

[Bhikkhu Pesala]

I have no idea why people make huge animated gifs and expect them to display without using a lot of CPU cycles. I think people should use flash or some other video format for such large animations. I guess these are some kind of Manga? Use a viewer that is designed for the task, not a general purpose image viewer.

[als]

Both the Internet Explorer and Opera web browsers as well as the Windows preview display these images just fine. Yes, they too use a lot of CPU time, but significant less than IrfanView and with a lot better image quality when resizing. But that's not the real problem anyway, as I wrote I wasn't even sure if that can be considered a bug. What bothers me more is the automatic resizing or not resizing, respectively, regardless of the program's settings and that I can't scroll to actually see the whole image when it's not resized.

I wholeheartedly agree that these oversized animations don't make much sense, I can see that without having any actual knowledge about the topic. But they're out there anyway, and it's just annoying when I want to browse through that comic's archive that I saved to my hard drive and come across an animated page which promptly throws IrfanView completely off balance.