I want to save my files to a Photoshop file size of 8 (on a scale of 1-12).

Is there any way to scan for images that do NOT currently have this setting? I would batch-file only those that needed changing, but prefer not to destructively edit my "good" images...

V/R
~Mike

Sounds like you might be planning to save your files in JPEG format (with a quality setting of '8').

If so, you are choosing to save in a 'lossy' compression format; a 'destructive' process. Maybe think again?


Cheers

Wollom

This is what I am trying to do with my current .jpgs :

I have .jpgs that happen to open up in a File Size of 12. These are too large.
I have .jpgs that open up in a File Size of 3. This is too lossy. Thus I'd like to re-format (re-save) them with the CORRECT file size of 8.

Is there a way to go through my folders of .jpgs to find out which ones are under-sized?

V/R
Michael

It's not clear from your message, but are these JPGs straight out of the camera or processed from RAW? If from the camera, do you have the original, full resolution JPGs safely stored away? As others have already noted, the concern is that you may be destroying data in your source image files that cannot be restored.

Obviously you can downsize images. But if you trying to re-save your JPGs at file size 3 back up to 8, this won't restore detail, the data is gone forever.

It sounds like hard drive storage space is lacking. Additional internal or external drives are relatively inexpensive. These would be good insurance in any case so you can back up duplicates of your pictures for safe keeping. CDs or DVDs are other options.

If you prefer to shoot JPGs in camera and you don't need the full resolution images, shoot at a large or medium resolution instead. This also keeps you from having to later "dumb down" images in Photoshop, which destroys image data.

If you are processing RAW to make JPGs, most converters allow you to make JPGs at less than full resolution, or at a quality lower than 100%.

Paul

If you have JPEGs saved at quality 3, there's no way to bring them up to a higher quality - the information is gone and cannot be retrieved. You can save to a lower quality, not a higher. To be precise, your software may let you think you are saving to a higher quality, but it's not possible.

As far as I know, there's no way to tell what quality setting a given jpeg was saved at.

Peter

Another note of caution, when you open a jpeg in PS and then save it again as a jpeg there will be a loss of information and quality, and increased chance of jpeg artifacts.

The numbers on the JPEG option panel reflect neither size nor image quality; they represent a set of parameters controlling the lossy encoding of the image. The encoding is carried out using 129 parameters. Every program creating a JPEG file uses some sets of parameters. PS allows for a selection from 12 different sets, some others allow for 100 sets, etc.

Of course if the degree of lossiness is increased, then the resulting file will be smaller - and the quality worse. But, again: you don't select the file size but the "degree of lossiness", where this "degree" can not be expressed as a single number.

As noted above, it is not possible to increase the quality of an existing JPEG image simply by encoding it with other "quality setting". However, that's not all to know. If you save the image with any different "quality" , the result will be definitively worse than the original was - even if the original saving occured with "3" and now you save it with "10". (Saving with "12" does not really reduce the quality, but the size will be unreasonable.)

Let me get this straight - if you select a higher number you get a larger file with better quality; if you select a smaller number you get a smaller file with lower quality. Yet, the numbers do not, according to you, reflect file size or quality.

Really, give us a break!

Peter

I see an important part of my post needs to be repeated:

if the degree of lossiness is increased, then the resulting file will be smaller - and the quality worse

The "quality level" regarding the resulting size and quality has only a relative meaning: higher quality results in better quality and larger file.

However, a given quality level with a given image can result in a larger or smaller file and in a better or worse quality than another quality level with another image.

Consequences:

• the quality level needs to be selected depending on the image (and, of course, on the intended presentation)
• aiming at roughly equal JPEG file size is nonsensical

No break, huh? Oh well.

Peter