Zoom In works very slow

[OhadR]

hi
thanks for your app ! it is great.
however, i used to work with version 4, which was great. when i installed ver 4.25 (and now 4.27), i've noticed that the Zoom In option works very slow. meaning, when i see a JPEG file, and wanna zoom in using the +, it works very slowly. it happens on other machines as well...
and to make myself maybe clearer: i work on big JPEGs, like 4000 x 3000. zooming in working slow, and when im in 300-400% in works even worse.
zoom out works slow as well.
any idea?
thanks again,
Ohad
IrfanView 4.27
Windows XP Home SP3

[Bhikkhu Pesala]

Turn off resample when zooming, fitting image in View, Display Options.

[OhadR]

you are the man !!
it really solved this issue. so im sorry, this was not a bug.
can u give me a few words, what it means "resample for zooming"? or when can i read about it ?
thanks a lot!
Ohad .

[Bhikkhu Pesala]

Resampling makes the image look smoother while viewing. It doesn't change the image on disk even if you save it.

IMO there is not much point to using this option — as you noticed it is hopelessly slow for large images or even for medium sized images if you zoom in far enough.

[OhadR]

i understand. thank u so much again !
-Ohad

[bugblatter]

Bhikkhu, actually I really like this feature. It makes it possible to discern small details in images, kind of like those fake zoom-ins in the CSI-like TV shows, especially hard-to-read text. It also makes small pictures look better in irfanview slideshows.

Like you said, the unfortunate thing is it can hang the program while it works for seemingly forever if you zoom in far enough. I wish there were a way to cancel the zoom-in, like with the Escape key, to regain control.

[jsc37227]

Irfan released a test version of 4.27 where you can turn off "resample while zooming", and use "shift-F5" to force a resample on the zoomed image (operates like F5 alone did in 4.25). Still takes a long time to resample the full image, but you don't have to wait for every resample step.

I use it that way for b&w tiff line drawing images. Otherwise, the zoomed area is illegible.

You'll have to email Irfan directly, and ask him for a link. (I wish he would post his test versions or allow the moderators here to do it - it would save a lot of repeated troubles and questions.)

[Bhikkhu Pesala]

You can solve the problem by turning off resample to fit, turn on resample for zooming, then use marquee select to zoom in. Press the zoom shortcut to zoom out one step and the image will be resampled. Press the "f" shortcut to zoom back out to the full image without any resampling steps.