4 Replies Latest reply on Jan 18, 2012 12:42 PM by system10

    Compression on import

    system10

      Hi

       

      When an image is imported to PS touch it is visably compressed. This can be seen by comparing the image in the standard android gallery app with the same imported image from within PS touch. Very severe blocking is visable, specifically on diagonals. Great images which look nice and clean in the viewer look bad once opened in PS touch on the same device

       

      Please could someone explain to me what is causing this problem and how i can use PS to make images look better rather than degraded from the start?

       

      I have a Samsung Galaxy Tab 10.1

      My test image is a Kodak marcie exported from PS cs5 as a jpeg set to max quality. Should be easy to recreate my issue, - zoom in on the eyes or diagonal edge of face to really see the difference.

       

      Many Thanks

      R

        • 1. Re: Compression on import
          David__B Adobe Employee

          Hi system10,

           

          I wanted to try recreating the behavior you described but I had a few questions before I tested. I was wondering what the pixel dimensions were of the image that you had exported from PS CS5, the largest supported in PS Touch is 1600x1600. I can save at max quality but just want to ensure I was doing something similiar before I started. Also, did you have to resize the image during the import process? I'll test based on your answers.

           

          Thanks,

           

          -Dave

          • 2. Re: Compression on import
            system10 Level 1

            Hi David

             

            Many thanks for coming back to me.

             

            My test was of muliple sizes all exceeding 1600 in either one or both dimensions. Any camera still is unlikely to fit within the constraints of a 1600 square. I will try today if I have time to 'cookie cutter' a 1600 square from the marcie to test.

            It's a fair possibility that the rescale is responsible for the artifacts I am seeing. This would tie up with the popular forum frustration of low quality exports.

             

            Best

            R

             

             

             

             

            Sent from my BlackBerry® wireless device

            • 3. Re: Compression on import
              system10 Level 1

              Hi David

               

              I have done another test where i have 'cookie cut' a 1600x1600 square from

              the marcie test frame. Again this was exported from cs5 as a max quality

              jpg.

              When imported into ps touch i do not see any compression or resolution

              artifacts.

               

              This strongly points to a problem with resizing on import.

               

              What are your findings?

               

              Thanks

              • 4. Re: Compression on import
                David__B Adobe Employee

                Hi system10,

                 

                For my test I created 3000 x 24000 pixel image then created a 1 pixel line that was perfectly vertical and close to the height of the image. From there I rotated it over and over 5 degrees with the center of screen being the fulcrum. After which I saved the source image as a high quality jpeg. Then I tested importing and resizing it to 1600 x 1600 in both PS Touch and Photoshop CS5. In Photoshop CS5 it was 53% reduction using the bicubic algorithm to fit within the 1600x1600 canvas. I definately saw quality loss when importing and downsampling to 1600 x 1600 in PS Touch that I wasn't seeing in Photoshop CS5 when performing a similiar downsizing process.

                 

                Thanks posting about this I'll share my finding with the product team.

                 

                -Dave

                 

                source image:

                quality_test.jpg

                • 5. Re: Compression on import
                  system10 Level 1

                  Thanks

                  I look forward to the update