[badtz]

If you didn't want to add additional artifacts to a JPEG image, should you save the image to a TIFF and do the editing there?


afterwards, if you brought the edited TIFF image back down to the same JPEG [@ 75%] .... would it have gained more artifacts? or remain with the same amount as before the TIFF?



also, can photoshop rotate JPEGs w/out re-compressing the image?



thanks for any help!

[spiky_dog]

you're onto it: try to minimize the number of times you save as jpeg. this means using a non-lossy format when you're doing your editing, yes.

[badtz]

But after you're done editing ..... and you bring it back down to JPEG .... is there less loss by using the same jpeg compression rate [i.e. 75%] versus using a different rate than before [i.e. 90%]?


or does it not matter , and you'll concur another round of compression artifacts on the image?

[cnelson87]

EVERYTIME you edit and save as jpg, no matter what setting, you will introduce new artifacts and quality loss.
Save as lossless tif (or psd) if you need to do multiple edits, and save-as jpg only when finished.
The rotating jpg issue has come up before with no definite answer. Photoshop and iPhoto can not do it. It may be possible to do it from command line but I haven't heard of a way.

[thePurpleGiant]

Originally posted by badtz:
also, can photoshop rotate JPEGs w/out re-compressing the image?

Photoshop can't, but GraphicConverter can. It provides lossless jpeg rotation, and cropping. To do a lossless crop, you are limited to exactly where you can crop the image, but it does work well.

[badtz]

Originally posted by thePurpleGiant:
Photoshop can't, but GraphicConverter can. It provides lossless jpeg rotation, and cropping. To do a lossless crop, you are limited to exactly where you can crop the image, but it does work well.

odd that graphic converter can do it, but not photoshop.

[cnelson87]

Wow, pretty cool. Is it truely lossless, or merely visually lossless? I'll have to try it out for myself. Thanks for the heads-up.

Originally posted by thePurpleGiant:
Photoshop can't, but GraphicConverter can. It provides lossless jpeg rotation, and cropping. To do a lossless crop, you are limited to exactly where you can crop the image, but it does work well.

[cnelson87]

wow, never used Graphic Converter before, came pre-installed on my machine. how the h*ll do you use this thing???

hey purplegiant, how did you do that?

[iChelle]

sorry to resurrect an old thread but i work with photos often and had a question. usually digital cams automatically save pics as .jpegs. when i do a drag & drop transfer from memory card to hard drive, the pics are all obviously saved as jpegs as well. should i be saving them as something else, i.e. psd, in order to maintain as much quality as possible?

does it introduce aritfacts when saving from (original) jpeg to a .psd? how about when saving from (original) jpeg to a .tiff? btw, i know .tiffs are made for print.

thanks all!

[gadster]

Originally posted by iChelle:
sorry to resurrect an old thread but i work with photos often and had a question. usually digital cams automatically save pics as .jpegs. when i do a drag & drop transfer from memory card to hard drive, the pics are all obviously saved as jpegs as well. should i be saving them as something else, i.e. psd, in order to maintain as much quality as possible?

does it introduce aritfacts when saving from (original) jpeg to a .psd? how about when saving from (original) jpeg to a .tiff? btw, i know .tiffs are made for print.

thanks all!

Check your camera manual to see if you can capture images as TIFF or RAW. If not, make sure the quality setting is 'Max' (or similar - usually refers to amount of lossiness). Also make sure the camera is sampling at its biggest size (eg 1200x1000 vs 800x600). Then open images in photoshop, do your thing, and save as Photoshop files. To offload the images elsewhere � resize �flatten to tiff/jpeg or whatever, and save out. The main thing to remember is: don't save your working files in lossy formats (eg: jpeg).

[iChelle]

my cam does have a .tiff format.
anyway, does iphoto allow storing of psd? i have about 700 original photos in it all as jpegs (straight from cam).

[godzookie2k]

when you copy from camera to hard drive you are just moving the file around which won't create artifacts. Its just copying data. When you are editing your photos you should be editing them as psd's and saving them as psd's unless you are going to be sending them to press or something. Tiffs are fine for that case, but if you are editing a layered document, saving it as a layered tiff is a waste of space.

[iChelle]

thanks for the info. but i'm still wondering if iphoto can store psd's. anyone?