Saving images in Chrome

[mbalensiefer]

Hi!
 When Web browsers save images such as (an opened) jpeg locally, does the jpeg get re-compressed, or does the browser download the original file without creating a destructive edit?

[louoates]

I'm not a techie in such matters but logic tells me that since you are not opening the file, simply viewing it in a browser, then copying it, no destruction or compression would occur.

[kikashi]

Hi!
 When Web browsers save images such as (an opened) jpeg locally, does the jpeg get re-compressed, or does the browser download the original file without creating a destructive edit?

I'd be surprised if it did anything other than download and save the file, non-destructively.

Jeremy

[bill t.]

Post a picture.  Download and save it.  Layer it with the original in Photoshop.  Change the top layer mode to "Difference."  If there is any difference, you will think you are having an LSD flashback.

Tell me what you see, because I am too lazy to try that myself.   

[mbalensiefer]

Here is my result.

In Photoshop, however, if I use the levels slider on the difference layer, I can see a big difference! Am I supposed to see a difference?

[bill t.]

If that's what you get, there is no difference!   Only differences will light up, editing one of the images creates a difference which will light up on any pixels that don't match on both layers.  Assuming the top layer of the two images is in Difference mode.

Edit...but don't assume that sites that accept uploaded pictures will not resize or compress them before making them available for download.  Obviously the one you used left your file intact, they get a gold star.