Why does the file size reduce when you edit a digital photo?

Question: Why does the file size reduce when you edit a digital photo!?

When I change the exposure or something else pretty basic I notice that the size of the file reduces considerably!.Why!? and does that mean the chances of getting a large print without undue noise will also reduce!?Www@QuestionHome@Com

Best Answer - Chosen by Asker:

YES!.!.! Each time you load a jpg into your image editing program and do - anything - to it, then re-save it, your squishing more and more detail out of it and making the future use of the image grim!.!.!.!. In fact, you could reach a point where even on the screen it looks rotten!.!.

If you need to do a large amount of editing or will be doing it over a few days you want to take the original shot and save it as a TIFF or even a BMP BEFORE you do anything to the image (better yet, shoot in RAW if you can) !.!.!.

Some image editing programs have a scale you can adjust as to the amount of compression that is put on you JPG's!.!. Learn where this is in your program and play with the scale to learn where the Less / More compression settings are!. This will help a lil but still not the best!.

You need to find a Loss-less way of saving and re-saving your work in order to NOT have what is happening to you happen, and normal TIFF's or BMP's are a loss-less file - but, they become BIG files!.!.

Once you are all finished with all your image editing you could do a file save as - and re-save back into a compressed JPG if you want to e-mail or post on the web someplace!. For prints I would either not mess with the camera's JPG and print what is there, or I would turn it into a TIFF for editing then print!.!.!.

Bob - TucsonWww@QuestionHome@Com

File size will decrease if you crop the image!.It will also change if you save the file in a format that compresses,like JPEG!.Try and "Save As" a TIFF and see if the same thing happens,TIFFs are not compressed!.Www@QuestionHome@Com

The file size changes because when you edit it the detail reduces!.

Hope this helps :)Www@QuestionHome@Com