pixellation

[Theo Scholten]

I have used Irfanview for many years and seldom had a problem. For the past 2 years, though, I sometimes encounter a phenomenon that I can only think of as pronounced pixellation, but have no idea what I do wrong to cause this. Can you explain?

[Bhikkhu Pesala]

The compression/quality slider is too low — apparently set to 11. The lowest useful value that I found is about 25, but YMMV depending on the type of image.

Probably, you're using the "Save for the web" option but setting the target file size (on disk) too low for the size (in pixels) of the image.