How to fix JPEG files

[don_myers1]

I have a JPEG file that needs retouching, and I know that is a no - no. If I save the file as a TIFF, can it be "doctored"

without comprimising the picture, or am I just out of luck?

 

Thanks for your help.

 

Don

[leicaglow]

Hi Don, I don't know why it's a no-no. I do it all the time. Is it nicer to work with a RAW or TIFF file? Sure. There's no reason you can't work with JPEG's though. It can also be doctored as a TIFF, but I don't know that you gain a whole lot by doing that.

[jillsphotos]

Every time you open and then save a JPEG file, you loose detail due to how JPEGs compress. Consider the example

of working with a xerox of a xerox of a xerox.... each successive copy is slightly worse in quality.

 

Instead save it as a TFF and store that as your master. You can then edit the TIFF, and save it without fear of

loss. (make sure compression is off) Save it as a different file name than your master. That way if you screw

it up, you can still go back to your master and start from scratch.

[bill_tuthill]

If you save a JPEG at exactly the same compression settings and chroma subsampling,

damage is minimized.

The GIMP image editor has an option to "save using original JPEG parameters"

that you can set from Save > Advanced Settings.

Highly recommended.

 

Unless you'll be wanting to edit it again and again,

no point saving as TIFF because the artifacts are already in there.

[ronald_moravec1]

When you first open the original JPEG, save it as a 16 bit TIFF or Photoshop. Make all the manipulations you want. Open and

close as often as you want. Save it even in layers.

 

Make all your final size JPEGS using that as the master. Flatten file, do final sharpening at final size, save as a JPEG. You will

not get artifacts. Return to that master to make any other size JPEGS.

[garydem]

certainly you can pp a jpeg. however you should know going in that the joeg will not take the kind a heavy duty pping that a raw can. therefore, the jpeg has to shot closer to correct in the camera. simply because you cannot fix it very easily if the shot is too far off from right. in that sense the good jpeg is harder to shoot because the margin for error is much smaller that the raw shot.

 

i shoot joeg all the time. my jpegs are downloaded to the pc and then opened in pe6, usually, i also have cs2. after any pp the image is saved as a tiff. all future work is done from the tiff. the jpeg goes into a jpeg holdall folder for future need if any. i never save the jpeg as a jpeg. if jpegs are saved qulity drops with each successive save.

[garrison_k.]

"I have a JPEG file that needs retouching, and I know that is a no - no. If I save the file as a TIFF, can it be

"doctored" without comprimising the picture, or am I just out of luck?"

 

If you save it as a tif, you will still be limited by the amount of altering you can do. Merely saving as a tif

doesn't open magic doors and the prevent posterization and artifacts. You can of course do a great deal with a

jpg and in this case, no harm in re-touching or cloning next door pixles to get rid of telephone poles sticking

out of the back of heads etc. It's when you wish to do large amounts of curves adjustments, color correction, or

sharpening etc that 8-bit files will show their weakness.

 

Quality drops, and compression only happens, if you have altered the jpg after you have opened it and re-save as

jpg. If you don't alter it, you can open and close the jpg as many times as you wish and nothing will happen. It

just closes the way it was opened.