Announcement

Collapse
No announcement yet.

Saving grayscale image to PDF

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

    Saving grayscale image to PDF

    Hi,
    I have a following problem: I'm saving an 8-bit grayscale image to PDF, but the compression settings for "grayscale images" do not have any effects. Instead, it is the "true color images" settings which work, but with undesirable results, e.g. if I choose "JPEG (best quality)" then the image in PDF has decreased color depth. I tried to look at the image information to make sure that the original image is indeed 8-bit grayscale, but the PDF plugin simply seems not to recognize that. Am I doing anything wrong?
    Thanks
    hombre

    #2
    Originally posted by hombre View Post
    Hi,
    I have a following problem: I'm saving an 8-bit grayscale image to PDF, but the compression settings for "grayscale images" do not have any effects.
    Please check your palette. It must contain 256 entries ascending from (0,0,0) to (255,255,255).

    Comment


      #3
      Originally posted by impdf View Post
      Please check your palette. It must contain 256 entries ascending from (0,0,0) to (255,255,255).
      I checked the palette and it looks exactly as you wrote.

      I would attach an example to the forum but I get an error on uploading the file:
      "
      Fatal error:

      Could not create file system directory to hold your attachment.

      Unable to proceed with save while $errors array is not empty in class vB_DataManager_AttachmentFiledata in [path]/includes/class_dm.php on line 849
      "

      Comment


        #4
        Hi,

        for the upload problems, please read this article

        Stefan

        Comment


          #5
          Originally posted by stefan View Post
          Hi,

          for the upload problems, please read this article

          Stefan
          Unfortunately that didn't help either...

          Comment


            #6
            The problem is quite simple: just convert any image to grayscale and try saving it as PDF. The compression settings for grayscale will not have any effect, while the true color will, which will of course result in a bad image in pdf because the original image is grayscale.

            Is anybody able to reproduce this? I'm using v4.30 on Win Wista.

            Comment


              #7
              Originally posted by hombre View Post
              The problem is quite simple: just convert any image to grayscale and try saving it as PDF. The compression settings for grayscale will not have any effect, while the true color will, which will of course result in a bad image in pdf because the original image is grayscale.

              Is anybody able to reproduce this? I'm using v4.30 on Win Wista.
              We will check if this is reproducable. But even if for some reason the rgb filter setting is taken instead of the gray one, I would not expect a difference in the color space. What do you expect in the resulting image?

              Comment


                #8
                Hi,

                I can confirm this problem with IV 4.30 on Windows 7 x64.

                @impdf: a feautre request: is it possible to have also metric measurement for border sizes?

                Regards
                Nils

                Comment


                  #9
                  Originally posted by derniwi View Post
                  @impdf: a feautre request: is it possible to have also metric measurement for border sizes?
                  Never mix thread contents ;-)

                  The "Unit used for dimensions" on the "General" tab should do the trick.

                  Comment


                    #10
                    Originally posted by impdf View Post
                    We will check if this is reproducable. But even if for some reason the rgb filter setting is taken instead of the gray one, I would not expect a difference in the color space. What do you expect in the resulting image?
                    Sorry, I was wrong in reporting that the broken image has decreased color depth, that was my first impression. In fact it looks like this:



                    This is with true color compression set to "JPEG (best quality)".

                    Comment


                      #11
                      Originally posted by hombre View Post
                      Sorry, I was wrong in reporting that the broken image has decreased color depth, that was my first impression. In fact it looks like this:



                      This is with true color compression set to "JPEG (best quality)".
                      I looks like that the ui part randomly chooses for the gray filter the rgb one. Still it takes the quality from gray. So as a temporary solution: Select the same compression setting for gray and rgb and the result for gray should be as expected.

                      Comment


                        #12
                        Originally posted by impdf View Post
                        I looks like that the ui part randomly chooses for the gray filter the rgb one. Still it takes the quality from gray. So as a temporary solution: Select the same compression setting for gray and rgb and the result for gray should be as expected.
                        That works, thanks!

                        Comment

                        Working...
                        X