9 Replies Latest reply on Mar 19, 2014 10:04 AM by Chuck Uebele

    Understanding Pixels

    Mary Lou Frost Level 1

      I recently saw an image (which had been opened from Adobe Camera Raw and had all of its original pixels) get saved as a maximum quality jpeg.  Before it was saved the Image Size window indicated that it had about 4500 pixels on the long side and was about 32 Mb in size.

       

      After it was saved as a jpeg file, it was about 7 Mb in filesize.

       

      It was subsequently reopened from the jpeg file and the Image Size window showed exactly the same information as was in the original file before it was saved as a jpeg.

       

      How can this be?  Is Photoshop reconstructing the pixels that went through lossy compression as a jpeg?

       

      Mary Lou