Announcement

Collapse
No announcement yet.

- JPG compression artefacts

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • - JPG compression artefacts

    The following photo was rejected. Reason: - JPG compression artefacts
    I myself don't see it, but the screeners apparantly well

    What can I do to avoid this problem?

    Paul Stam

  • #2
    Paul I left you a message in one of your latest rejection. Here's what you'll find in the upload guideline :

    6.2 Compression

    Save your images at a high JPG quality or low compression settings. Saving at low quality settings or using a high compression rate is great for saving disk space but it means you are losing large amounts of quality from the image, areas which are the first to show signs of over-compression are where colors border each other in particular the registration and cockpit areas.

    Examples of not acceptable photos






    hope it helps,
    Best regards
    Alex

    Comment


    • #3
      Sorry Alex, I had not read your comment

      This is your comment: Screener's Comments: still the very same compression problem Paul. Please remember to always save your pics at the highest qulity possible. This'll avoid the compression - Regards


      But I do save my pictures in the highest quality

      Image options: 12 maximum

      Format options: Baseline "Standard"

      Paul Stam

      Comment


      • #4
        What about your camera mode ? are you on the highest quality settings too ?

        Comment


        • #5
          Yes I have my camera always in the highest level.


          The rejected photo OK-CGK of CSA, I posted is only 106kb.
          I use a noisefilter and when I have used that the photos are only between 100kb and 150 kb.
          Not using the noisefilter my photo of OK-CGK is saved with 641KB,. Is that the reason of artefacts?
          Look at the photos
          The first one is with noisefilter, tehe second without noisefilter.

          Kindly regards,

          Paul Stam

          Comment


          • #6
            Originally posted by Paul Stam View Post
            Yes I have my camera always in the highest level.


            The rejected photo OK-CGK of CSA, I posted is only 106kb.
            I use a noisefilter and when I have used that the photos are only between 100kb and 150 kb.
            Not using the noisefilter my photo of OK-CGK is saved with 641KB,. Is that the reason of artefacts?
            Look at the photos
            The first one is with noisefilter, tehe second without noisefilter.

            Kindly regards,

            Paul Stam
            So I guess your noise filter programm is fully responsible there... there's no reason your pics are at 100kb. all my pics are between 800kb and 1mo.

            Comment


            • #7
              I first crop and resize, then proceed further in the processing process. I never have compression artefacts.

              I had them when I first processed and afterwards cropped/resized and saved. (I never work with RAW, always JPG). Especially when you sharpen FIRST and then resize/crop/save then you can have artefacts.

              Comment


              • #8
                Dag Hinkelbein,

                I do that. First I crop and then resize. The photo of PH-BXM was after cropping: width: 3369 pixels and height 2246 pixels and 2,92MB.

                Then I resized in two steps to 1024 x 682. And then I have compression and artefacts.

                By the way can someone tell me where in the photo of PH-BXM are the artefacts. I don't see them.

                Paul Stam

                Comment


                • #9
                  Hoi Paul,

                  When you look closely, you see that there is something not correct with or by the registration number. This is the place where jpg-artefacts mostly occur. I must admit, in your case you have to look closely, but I see it. And apparently did the screeners.

                  Why resize in two steps? I always crop first (after horizon levelling), then resize. In one step: from big to 1024. No steps in between needed.

                  I have had pics rejected, but not due to artefacts. But I know that there are some who, just like you, resize in two or even more steps, but I haven't yet seen the benefit of that.

                  Groeten,

                  Hinkelbein

                  Comment


                  • #10
                    Hallo Paul,

                    As Mr.Hinkelbein says, even I can see the artifacts!
                    And believe me if there is a bad processor here, then it most be me!

                    And sometimes the rejections me!

                    PlaneCatcher.

                    Comment


                    • #11
                      Well I have to buy new eyes or a new PC, because I see no artefacts with or by the registration number, even when I use the equalize tool I see nothing.

                      I resize in two steps because that was once recommended to me in this forum by Seahawk.

                      Paul Stam

                      Comment


                      • #12
                        In it's own workflow he says nothing about it. The only thing what you can do is I think to do it in one step.
                        I have to say that I also see not much on your photo. I see that on a lot of reg/photo's, but there must be a difference

                        Comment


                        • #13
                          Just a question: when exactly, after which steps, do you save the photo?
                          My photos on Flickr www.flickr.com/photos/geridominguez

                          Comment


                          • #14
                            Originally posted by LX-A343 View Post
                            Just a question: when exactly, after which steps, do you save the photo?
                            This is how I do it:
                            - crop/resize
                            - processing
                            - saving

                            Comment


                            • #15
                              I do it in the same way as mr. Hinkelbein.

                              Crop
                              resize
                              processing
                              saving.

                              Paul Stam

                              Comment

                              Working...
                              X