no bug Thumbnail generation stops

[lister]

I've noticed that sometimes Irfanview just stops generating thumbnails for folders.

EG, folder with 350 images, average size of pic 600-700kb, scrolling down while its generating just stops. Hitting f5 starts it again, and usually completes. Sometimes it takes another refresh.

[Sjef]

Can't produce this bug here. I've scanned a folder with many subfolders containing WMF files. In total 18627 files. Most bitmap viewers have trouble with WMF vectors but IrfanView doesn't.
Maybe it was your system memory or a corrupted file. Or maybe IrfanView couldn't Resample some kind of files which caused your problem. Try again after unchecking this Resampling in the Thumbnails Option menu.

[melty88]

I am also seeing this bug, and it's still present in IrfanView 4.23. I see this in many different image directories with varying numbers of files. It tends to occur in directories with a large number of JPG's (e.g. 1000+). I suspect that IrfanView is hitting the maximum of 2GB per app in windows XP. Here is an example where I am currently seeing this:

# of JPG's in thumbnail directory: 1420
JPG sizes: ranges from 33KB-2000KB, average size = 273KB
Thumbnail size: 600x600
"Resample" and "stretch small images" both set
Auto-scroll off
Display thumbnails alphabetically
XP Professional
3GB ram
1920x1200 screen, thumbnail window maximized
IrfanView 4.23

When I "show thumbnails" in this directory, it stops showing the rest of the thumbnails at the 398th JPG (sorted alphabetically). It stops at the same image every time I reload. It allows me to see the titles of all 1420 images, and allocates screen area to all images, but it only shows the titles for images beyond the 398th JPG. When I turn resample off, it also stops at the exact same spot (398th JPG). Looking at my free system RAM, it never drops below 1.7GB free. Also, once it gets to the 398th image, it VERY quickly loads the ~1000 remaining images in the directory, at a much faster rate. It does not appear to be loading those images at all.

When I change the thumbnail size to 200x200 pixels, it *does* show all 1420 images. Also, when I remove about 300 images from the directory (it does not matter which 300... The first 300, last 300, or middle 300 images (alphabetically), it doesn't matter, it shows the remaining ~1100 images.

Can IrfanView, as a single process/application, address more than 2GB of RAM under windows XP 32-bit? I know there are tricks you can play in windows to get around this limit, but I suspect that irfanview is limited to 2GB of addressable space. Quick calculation: 1420 images * 600x600 pixels each * 4 bytes/pixel uncompressed is slightly over 2GB. This is probably the root of the problem, and it explains why removing about 30% of the 1420 images allows IrfanView to display the whole thing, regardless of whether resampling is on/off.

Does someone have an alternate explanation for this issue? Thanks!

[Sjef]

Many files in folder

I have opened a directory containing over 3700 files whith an average of 1000x1000 pixels using IrfanView 4.23. Together they are 1.4 Gb. Resample yes or no didn't matter. Pixels thumbnails: 150x150. No autoscroll. It took 3:20 minutes and no trouble at all... My computer's memory is 1 Gb (XPSP3).

I already asked Irfan Skiljan to look at the possibility of making it able to put files in a thumbs-database. That is, only the thumbs of the user's choice are put in such a database.

[Jaff]

EG, folder with 350 images, average size of pic 600-700kb

It may happen when an out of memory error is given by a very big image or maybe an error in some plugin.
FIle size dosen't matter, the size of image really does. ex: 200kb filsize and a 5000x2000 picture

Try moving some pics form folder until you don't recive that stop of generating thumbs in that folder and see what file makes that bug happen.

[melty88]

I have opened a directory containing over 3700 files whith an average of 1000x1000 pixels using IrfanView 4.23. Together they are 1.4 Gb. Resample yes or no didn't matter. Pixels thumbnails: 150x150. No autoscroll. It took 3:20 minutes and no trouble at all... My computer's memory is 1 Gb (XPSP3).

If my theory is correct, your example will not expose the problem because it has nothing to do with the actual size of the image. It is the number of pixels in each thumbnail * # of images * bytes/pixel. Irfanview seems to be uncompressing each image and storing them in RAM (allows you to quickly scroll through all of your images). In your case, 3700 images * 150 * 150 * 4 (assuming 4 bytes/pixel = 32-bit color) = 333 megabytes of RAM, which isn't very big. This is well under the 2GB maximum per process allowed under 32-bit windows. Try increasing your thumbnail size to 400 x 400 and I bet all 3700 images will not load

The 2GB process limit in 32-bit windows can be lifted to ~3.2GB if your app uses PAE, I think, but that's pretty much the maximum for 32-bit windows. Can anyone using 64-bit windows and 4+ GB of RAM try to load a directory containing 2500 large JPG's using a thumbnail size of 600x600 and see if they all show up? (2500 * 600 *600 *4 = 3.6GB ram)

[Sjef]

Hi melty88,
You're right. When I set "thumbnails" of 600 x 600 it doesn't work for the whole directory. I tried this on a folder with 1600 large jpegs, but I still don't see the point of getting an "overview" of my jpegs this way on my screen with 1280 x 1024 pixels.

[garyHalcon]

Is this bug still considered outstanding?

I have my thumbnails displaying at 800 x 800 on a 3840 x 2160 resolution monitor. I have a folder of 3,984 RAW images. The thumbnail window title bar still shows the count generation going up but it stops displaying thumbnails around the 1115th image.

[Sjef]

Hi garyHalcon,
The FAQ-page of IrfanView says:

Answer: This is a Windows issue, the max. number of files in the thumbnails list is system dependent. Try to split files to several folders OR set a smaller thumb size in Thumbnail window options (to reduce system memory usage) ?

[Bhikkhu Pesala]

Not a bug in IrfanView