I'm an Adobe Stock contributor. File size is limited to 50MB. I have an action to do some minor tweaks to saved PSD files, convert from Adobe RGB to sRGB, and save the JPG file in a folder to upload.
I can't find a way to tell PS to limit the size of the JPG to 49MB (or even tell what size the JPG file will be before saving it). So I have to "trial and error" by resizing the PSD, save as JPG, see what size it is, still too big, delete JPG, rezise PSD smaller, save as JPG, see what size it is...
There are a couple of suggestions on this. One using Export suggests reducing the quality until the JPG size is correct. But file sizes are different for every image, so my action wouldn't work. The other suggests opening the files in ACR and exporting from there, but I can't see how to open PSD's in Bridge.
Please help! Thanks.
What quality level do you save your jpegs at? And what pixel size (and is there a particular minimum pixel size that you want to maintain) ?
There's usually no point in using Quality 12. Jpeg compression is always destructive, there is no such thing as "maximum quality" with jpeg.
Given that, you may as well get some payoff. Go down to 8 or 9, where you can really save some MBs, while still probably not getting any immediately visible degradation.
Adobe Stock is very picky about compression artifacts in submitted images - as they should be. Besides, I need to be able to limit the JPG file size no matter the size of the original file. I have files taken with several cameras, from a 20MP to 60MP. I certainly don't want to compress the small original files. Even files with the A7r IV vary wildly in size depending on the complexity of the image. So I need a way to leave small files alone but reduce large files.
Adobe Stock is very picky about compression artifacts in submitted images
Well, my point was just that there will always be compression artifacts in any jpeg. If they allow jpeg at all, they must allow some compression artifacts. It's just a question of how much.
Not familiar with Adobe Stock policies beyond that.
ACR can open tif, and you can convert psd to this format without loss. I use this trick often.
Unfortunately, Photoshop is not very efficient in the tasks of fine-tuning file conversion parameters (when you move the quality slider, several parameters actually change that affect the file size). It is possible to automate the task of estimating the file size with a script, however this will not work quickly.
You can try Image Magik, there is a convert command, which, among other parameters, can limit the file size:
convert dsc_6371.psd -define jpeg:extent=51200kb dsc_6371.jpg
You can automate the conversion of entire directories - I think you can find in web scripts examples for Windows.
Converting to TIFF and opening in ACR works. I've run a few through this process and the resulting JPG looks identical to the larger-than-acceptable JPG file at 400%. Thanks for the tip!
For completeness, Export > Save for Web (Legacy) includes an optimisation feature:
I remember that this option was, but could not find it 🤦
Does it work when recording in action?
I don't recall it working with an action or ScriptingListener...
In action this feature is not recorded. Recently faced the need to automate conservation with limited size.
The answer was found here in one of the branches of the community, there was a script in which you can choose the desired file size.
So I have to "trial and error" by resizing the PSD, save as JPG, see what size it is, still too big, delete JPG, rezise PSD smaller, save as JPG, see what size it is...
These steps could all be scripted!
One more to add 🙂
If you use Lightroom, you can specify the maximum file size on Export