export to smaller file size has boudary?

[that35510420xudu]

Hi,

How to get the files size even smaller?

I have an image (3 MB) that I want in a smaller file size (150kB). But in PS the export as jpg quality setting makes the file output 350 kB. Also tried script/image processing / quality setting to 1, same result around 350 kB. 

There must be a way to compress even more? 

Also I want to do this in batch for a series of images, so if the solution could be able to, that would be great.

[didiermazier]

Maybe if your pic is 16bits/channels convert first to 8 bits/channel…

What is the pixels size of these images?

[that35510420xudu]

images are 1920-1080 24 bit. But I see no 8 bit option on the jpg export selection.

[Bojan Živković · Accepted solution]

Have you tried Export > Save for Web > Optimize to File Size?

[that35510420xudu]

Ah, optimize for web, this is indeed a bit more compression. Works for what I need on one image. Thanks

Now only I need it to work in batch. I created a action for this save-type. But the smaller file-size does not work in batch, strangs.. solo it works great.

[Stephen Marsh]

But the smaller file-size does not work in batch, strangs.. solo it works great.

By @that35510420xudu

That's correct, actions can't record the optimize to target file size found in Save for Web (Legacy). The new Export As feature doesn't doesn't offer a target file size option and even if it did, Adobe has not made the feature available for action recording or scripting.

This leaves scripting via .JSX or .PSJS to save a file, check the file size against a target value and repeat and overwrite with a lower quality value until the target size is achieved.... If that is even possible, as image content plays a large part for JPEG.

[Stephen Marsh]

Three different scripts to automatically save JPEG to a target file size, which can be used in batch processing.

https://mindfulretouch.com/the-course/saving/saving-quality/

or

https://codebybrett.github.io/savesmalljpeg/

or

https://community.adobe.com/t5/photoshop-ecosystem-discussions/slow-operation-of-the-script/td-p/135...

[D Fosse]

Just to illustrate how much image content affects jpeg file sizes. These are both 1920 x 1080 pixels Save For Web at quality 60:

Flat areas compress much better than busy detail.

[Stephen Marsh]

images are 1920-1080 24 bit. But I see no 8 bit option on the jpg export selection.

By @that35510420xudu

RGB 24 bit (total) = R (8 bits per channel) + G (8 bits per channel) + B (8 bits per channel)

Photoshop’s Image > Mode menu.