Resize / Compress Image to a required filesize?

[OxidoEX]

Hi,

 

I would like to know how can I resize an image to a specific filesize in jpg format? I work with some scanned images and I usually crop required part of those images and I save them as jpg. But I also need to resize those saved jpg files to a certain filesize say, 30 KB or less. Usually I go through the long procedure of resizing down the final image and save it, and check the filesize in explorer. But sometimes I have to repeat resizing the image over and over till it shows 30 KB or less in explorer. And sometimes certain images are really hard to read at such filesizes but unfortunately its a requirement for a system. I know PNG files maintain better quality but I need them only as jpg. 

 

So please help me on this and also is this possible without much compromise on image quality?

[toe_head2001]

5 minutes ago, OxidoEX said:

I would like to know how can I resize an image to a specific filesize in jpg format?

 

Due to compression techniques, resolution does not dictate filesize.

 

If you want higher compression with less compression artifacts, take a look at the mozjpeg and guetzli encoders.

I have not done extensive comparisons myself, but there are some out there:

https://www.pixelz.com/blog/guetzli-mozjpeg-comparison/

[Zagna]

Irfanview has a very nice Save for Web plugin that allows resizing and automatic quality dropping, color reduction and other things to get an image down to a desireable file size.