Batch "resize" JPEG images to a fixed file size

Changing quality of the JPEG when saving an image, changes the file size. For eg. I have the following image. Dimension: 243px x 53 px Quality:100% File Size:9.7kb Background:

If I edit the image, keeping the dimensions and Quality same, the file size still falls to 6.1kb.

Problem: I am using Fotoresizer, which has a batch Quality change option, but due to the above problem, you cannot predict file size from quality alone. So when I batch change quality of a set of 200px x 300px images set at 20% quality, some files will turn out at 6kb, whereas others will turn out at 15kb, when the file size I want is 10kb.

Is there any program or programmable solution, which lets me save all files in a range of 10-11kb, without me manually changing the quality slider to change file size each time.

IDsizer will allow you to do this you can set a maximum file size from the interface and drop a batch of files to resize.

http://www.idimager.com/WP/?page_id=396

Just as an aside, be aware that the quality once you have done this may be quite poor. Also if the image will save at a high quality with out compression some files could be less than 10Kb.

Irfan View can convert image to jpeg of Your desired size.

Preconditions

If You will not find following option You have to download Irfan View plugins.

How to do it in Irfan View?

You have to press 'b' key or click on "file->batch conversion/rename". Then You can set desired file size of images You want to convert.

Notes

It might take longer to encode it. From what I tested it looks like that compression options are found by compressing image several times and doing binary search to find those which produce Your desired size; I may be wrong. :)