Announcement

Collapse
No announcement yet.

Zoom Window bug

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

    Zoom Window bug

    I am looking at a .tif file (14400x9600x1BBP) and have found that when I try to zoom in with a window, the display will show a different part of my image; i.e., if I zoom into a portion of the image on the right side, it will show me a portion of the image located near the center (possibly using the zoom factor of my window I picked). It will sometimes work correctly if I make my zoom window very small. Anyone seen this? I have it set to 'fit images to desktop'.

    I just upgraded to 4.10 from 3.89 which worked fine.

    Brent

    P.S. I really like the "center window when loading new image" option.

    #2
    This behaviour is present also in v4.00.

    Comment


      #3
      Originally posted by j7n View Post
      This behaviour is present also in v4.00.
      No, I don't believe so.
      Brentb73 is right, version 4.00 was in this function correct. I used it many times.
      I have the same problem now. When I have a large Tif file (multi page) and I want to zoom to a detail of the picture and use a rectangle window and the magnifier, the display shows an other region from picture then I selected before by window.
      Food for Irfan.....

      Thanks, Philip

      Comment


        #4
        Do these images use squared pixels or something else? So what are the dpi values.

        Comment


          #5
          Originally posted by midora View Post
          Do these images use squared pixels or something else? So what are the dpi values.
          How do you know if they are squared pixels?

          Here is some info from the image I'm looking at:
          Attached Files

          Comment


            #6
            The zoom bug in v4.10 is a different one. Old 4.00 also centered the picture if zoom in or zoom out was executed near the edge of the picture. DPI don't have to be defined at all.

            Comment


              #7
              Originally posted by midora View Post
              Do these images use squared pixels or something else? So what are the dpi values.
              Well, the size I'm talking about is 14043x9933x1 BPP and the resolution is 300x300 DPI.

              Comment


                #8
                Originally posted by philip307 View Post
                Well, the size I'm talking about is 14043x9933x1 BPP and the resolution is 300x300 DPI.
                Then there is no problem regarding the dimension of the pixels. There are ccitt fax tiffs
                around which do not have squared pixel and Irfanview has to stretch them.

                Comment


                  #9
                  I don't think IrfanView would do that, since it would require to inflate the bitmap to grayscale first which may require more memory than is available and after resampling lose a lot of quality.

                  I think the program would just carry over the DPI parameter.

                  -- This was wrong. In special cases IrfanView will apply point resampling.
                  Last edited by j7n; 26.10.2007, 05:08 PM.

                  Comment


                    #10
                    Originally posted by j7n View Post
                    I don't think IrfanView would do that, since it would require to inflate the bitmap to grayscale first which may require more memory than is available and after resampling lose a lot of quality.
                    First check, then think ;-)

                    Take one of the CCITT Faxes in the test suite if libtiff and you will see.

                    Or do the following test. Create a new image. Lets say 10x10x1bit with xdpi 100 ydpi 50.
                    Save it as a tiff. Reload the image. Have a look to image information.

                    Comment


                      #11
                      You are right. ops: I'm dissapointed that non-square pixels have poisoned the world of still images too. I already got sick of video files that always need to be resampled before viewing.

                      But back on topic. The imaginary dimensions of pixels have nothing to do with the fact that IrfanView centers the picture upon zooming. Moving of the viewport to center happens only if before zooming the topmost row or topleft column of pixels was visible.

                      Comment

                      Working...
                      X