JPEGs?

[Olaf]

We've talked about this before, but I've seen mention of it in various magazines and I keep thinking I'm doing it wrong. I download into a folder, and sometimes I move that folder, does that resave it? How many times do you have to save a JPEG before you have loss issues? What about when I burn to disk?

 

[kbnovak]

Olaf,

Simply moving the folder or burning the image to a disk does not re-save the file. The file only gets re-saved if it is changed in some way (resized, rotated, cropped, etc.). The image CAN degrade once it's been changed and re-saved.

I say CAN because of various factors. I've read, and it's been my experience, that if you use Photoshop setting of "12" when saving a JPEG, that you will likely never notice any difference in the image. Your safest bet is to always edit and save as a copy, never changing your original image.

Kevin

 

[Groucho]

Like kbnovak said - moving the file itself around doesn't change anything.

I would add that you can rotate your jpg without affecting the quality by doing a "lossless transformation" - using Irfanview, go into the Thumbnails (hit "T" or just load Irfanview Thumbnails), and right-click the picture (or series of pictures) that you want to rotate and go to JPG Lossless Operations, then Lossless transformation with selected thumbs. You can also set DPI, change the comments or IPTC metadata, flip the picture, or change the EXIF date while you're there.

There's also an option there for "optimize jpg", this uses a slightly different jpg compression that makes the file slightly smaller but it will take slightly longer to decompress for viewing. This does not affect the amount of picture information there is, just how it's stored.

 

[manning]

All my masters when shot in jpeg are saved as jpegs. If I am going to do a lot of editing and saving of a photo I will save it as a TIFF and work in tiff format. When done it can then saved as a new jpeg photo and/or TIFF.

 

[Groucho]

PNG gives you lossless compression, so your files won't be outlandishly huge like TIFF ones will. Give it a shot next time.

Brought to you by the Committee to Kill Off TIFF Once and For All, 2006.

 

[JR6ooo4]

any windows file copy function should be an exact copy of the original file. When you open a file in a program then save or "save as" is when it might change.

Mikeeee