JPG Quality Level 12 Compression Loss?

Sapearl- "smart object" is a Photoshop CS3 command that you use when you convert from adjusting in Camera Raw into regular Photoshop. Probably shouldn't have mentioned it in this post.

Certified Registered Nurse Anesthetist, Cleve. Clinic grad. Small world.

chauncey wrote in post #3487662
Sapearl- "smart object" is a Photoshop CS3 command that you use when you convert from adjusting in Camera Raw into regular Photoshop. Probably shouldn't have mentioned it in this post.

You're incorrect, smart objects have nothing to do with RAW. Any image from any source can be made a smart object.

Stuart-sorry for the delay, I punched the wrong button in the middle of the nite.

Basically "smart object" is a photoshop CS3 command that permentally saves your image as is. Probably shouldn't have mentioned it in this post.

Certified Registered Nurse Anesthetist. CCH grad. I was lucky and had a dull career.

prime80 wrote in post #3481825
OK, I'm confused here...If the initial image is a jpg out of a camera that is saved at PS equivelant of "8", then hasn't the lossy compression already thrown away the information required to make it a "12"? I understand that we can save-as a "12", but that can't return any image info that has already been discarded by the original jpeg compression. Aren't we just saving an "8" as a "12" and doing the least degradation of the "8" image on the resave? We're still stuck with the original "8" quality, aren't we?

Saving the file again as a quality level 12 will do no further harm to the file, not try to regain back any lost detail. Think of it like this. You fold a piece of paper 4 times to make it smaller (save with compression level 8 ). Then you open it back up and this time you fold it only two times (compression level 12). The damage has already been done to the paper but the next fold did no further damage.

tim wrote in post #3484255
Also, to make a layer a smart object you right click, or I think there's a menu command "paste as smart object" somewhere.

I believe it is File > Place. I used it on a collage I did for my FIL and it worked very well. A great thing about Smart Objects is that you can right click on the layer and choose EDIT. PS will open the file for you to make edits and when you resave the file those changes are automatically made to the Smart Object.

aaa

In2Photos wrote in post #3498615
Saving the file again as a quality level 12 will do no further harm to the file, not try to regain back any lost detail. Think of it like this. You fold a piece of paper 4 times to make it smaller (save with compression level 8 ). Then you open it back up and this time you fold it only two times (compression level 12). The damage has already been done to the paper but the next fold did no further damage.

That's how I understood it to work as well, but Rene's posts seem to contradict this.

prime80 wrote in post #3501355
That's how I understood it to work as well, but Rene's posts seem to contradict this.

When I read Rene's posts I don't see this contradiction.

I don't see a contradiction either?
When the jpg is 'decompressed', it doesn't mean any information is recovered that was lost in compression...

OK...I just guess I misunderstood the posts.