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Bitmap blur problem [modified]

Scheduled Pinned Locked Moved Graphics
helpgraphicsdata-structures
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  • N Naturality

    Yes, I did. However, I don't see how my pixel lookup is wrong. :S

    "Sir, I protest. I am NOT a merry man!"

    T Offline
    T Offline
    Tim Craig
    wrote on last edited by
    #19

    Ok, for starters I believe you're scanning the input image correctly now, x and y cover the correct pixels. However, you want to grab 3 pixels from the previous row right above the target pixel, three from the current row including the two on either side of the target, and the from the next row. So xp and yp have to take the values, [-1, 0, 1]. You start with 0 and your test of xp < 4 actually makes xp go from 0, 1, 2, 3. So you're getting the wrong pixel correlated. Also, after you call avg(), you should only be setting 1 pixel in the output image, the one at x, y. So the second set of for loops need to vanish.

    If you don't have the data, you're just another asshole with an opinion.

    N 1 Reply Last reply
    0
    • T Tim Craig

      Ok, for starters I believe you're scanning the input image correctly now, x and y cover the correct pixels. However, you want to grab 3 pixels from the previous row right above the target pixel, three from the current row including the two on either side of the target, and the from the next row. So xp and yp have to take the values, [-1, 0, 1]. You start with 0 and your test of xp < 4 actually makes xp go from 0, 1, 2, 3. So you're getting the wrong pixel correlated. Also, after you call avg(), you should only be setting 1 pixel in the output image, the one at x, y. So the second set of for loops need to vanish.

      If you don't have the data, you're just another asshole with an opinion.

      N Offline
      N Offline
      Naturality
      wrote on last edited by
      #20

      Thanks for the advice :D. But now, the output is just red and black lines :doh: Here's the updated code:

      unsigned int yp=0, xp=0;

      for(int y = 1; y < bmp.biHeight-1; y++){
      for(int x = 1; x < bmp.biWidth-1; x++){
      for(int i = 0; i < 9; i++){
      {
      get_pixel(x+xp,y+yp,blank[i],image);
      if(xp<2)
      xp++;
      else{
      xp = -1;
      yp++;}
      }
      }
      avg(blank, Merge, 9, Matrix);
      set_pixel(x,y,Merge,image2);
      clear_pixel(Merge);
      yp=-1, xp=-1;

      }}
      

      "Sir, I protest. I am NOT a merry man!"

      C T 3 Replies Last reply
      0
      • N Naturality

        Thanks for the advice :D. But now, the output is just red and black lines :doh: Here's the updated code:

        unsigned int yp=0, xp=0;

        for(int y = 1; y < bmp.biHeight-1; y++){
        for(int x = 1; x < bmp.biWidth-1; x++){
        for(int i = 0; i < 9; i++){
        {
        get_pixel(x+xp,y+yp,blank[i],image);
        if(xp<2)
        xp++;
        else{
        xp = -1;
        yp++;}
        }
        }
        avg(blank, Merge, 9, Matrix);
        set_pixel(x,y,Merge,image2);
        clear_pixel(Merge);
        yp=-1, xp=-1;

        }}
        

        "Sir, I protest. I am NOT a merry man!"

        C Offline
        C Offline
        Christian Graus
        wrote on last edited by
        #21

        Well, this is sure messy. Apart from anything else, all these function calls are going to slow your code down. avg works on a reference, it doesn't return a value ? yp and xp are zero at the start of the first loop, every other time they start at -1. I'm sure that's not the only issue, but it's an indication of the sort of problems you probably have.

        Christian Graus Please read this if you don't understand the answer I've given you "also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

        1 Reply Last reply
        0
        • N Naturality

          Thanks for the advice :D. But now, the output is just red and black lines :doh: Here's the updated code:

          unsigned int yp=0, xp=0;

          for(int y = 1; y < bmp.biHeight-1; y++){
          for(int x = 1; x < bmp.biWidth-1; x++){
          for(int i = 0; i < 9; i++){
          {
          get_pixel(x+xp,y+yp,blank[i],image);
          if(xp<2)
          xp++;
          else{
          xp = -1;
          yp++;}
          }
          }
          avg(blank, Merge, 9, Matrix);
          set_pixel(x,y,Merge,image2);
          clear_pixel(Merge);
          yp=-1, xp=-1;

          }}
          

          "Sir, I protest. I am NOT a merry man!"

          T Offline
          T Offline
          Tim Craig
          wrote on last edited by
          #22

          Christian is right about the initialization of xp and yp. And the xp<2 test is wrong. It's short, count it out in your fingers. :) He's right about it being very messy and inefficient. But right now it's more important for you to understand the algorithm.

          If you don't have the data, you're just another asshole with an opinion.

          1 Reply Last reply
          0
          • N Naturality

            Thanks for the advice :D. But now, the output is just red and black lines :doh: Here's the updated code:

            unsigned int yp=0, xp=0;

            for(int y = 1; y < bmp.biHeight-1; y++){
            for(int x = 1; x < bmp.biWidth-1; x++){
            for(int i = 0; i < 9; i++){
            {
            get_pixel(x+xp,y+yp,blank[i],image);
            if(xp<2)
            xp++;
            else{
            xp = -1;
            yp++;}
            }
            }
            avg(blank, Merge, 9, Matrix);
            set_pixel(x,y,Merge,image2);
            clear_pixel(Merge);
            yp=-1, xp=-1;

            }}
            

            "Sir, I protest. I am NOT a merry man!"

            T Offline
            T Offline
            Tim Craig
            wrote on last edited by
            #23

            Oh, one other question. You apparently assume that the pixels are RGB triples. You never check the bitmap info to make sure it matches. Were you told this is the structure of the image?

            If you don't have the data, you're just another asshole with an opinion.

            C 1 Reply Last reply
            0
            • T Tim Craig

              Oh, one other question. You apparently assume that the pixels are RGB triples. You never check the bitmap info to make sure it matches. Were you told this is the structure of the image?

              If you don't have the data, you're just another asshole with an opinion.

              C Offline
              C Offline
              Christian Graus
              wrote on last edited by
              #24

              Yeah, I spotted that, too. But, I assume it is, if it were 32 bit, he'd be complaining about pixels not processed, I reckon.

              Christian Graus Please read this if you don't understand the answer I've given you "also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

              N 2 Replies Last reply
              0
              • C Christian Graus

                Yeah, I spotted that, too. But, I assume it is, if it were 32 bit, he'd be complaining about pixels not processed, I reckon.

                Christian Graus Please read this if you don't understand the answer I've given you "also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

                N Offline
                N Offline
                Naturality
                wrote on last edited by
                #25

                I spotted the initialisation of xp and yp straight after posting. But it had no effect. :( I wasn't aware you could check if it was an RGBTRIPLE. Ignorance, I guess. How would I go about this? However, the other program I am using to create the random noise input image seems to work fine with the same values in the header BITMAPINFOHEADER and BITMAPFILEHEADERs. Oh, and, rather ironically, I used so many function calls to try and clean the for loops up. :^)

                "Sir, I protest. I am NOT a merry man!"

                T 1 Reply Last reply
                0
                • N Naturality

                  I spotted the initialisation of xp and yp straight after posting. But it had no effect. :( I wasn't aware you could check if it was an RGBTRIPLE. Ignorance, I guess. How would I go about this? However, the other program I am using to create the random noise input image seems to work fine with the same values in the header BITMAPINFOHEADER and BITMAPFILEHEADERs. Oh, and, rather ironically, I used so many function calls to try and clean the for loops up. :^)

                  "Sir, I protest. I am NOT a merry man!"

                  T Offline
                  T Offline
                  Tim Craig
                  wrote on last edited by
                  #26

                  Have you tried stepping through your code in the debugger to see if things actually work like you're expecting them to? I would have been doing that about 14 messages ago. :doh:

                  If you don't have the data, you're just another asshole with an opinion.

                  N 1 Reply Last reply
                  0
                  • T Tim Craig

                    Have you tried stepping through your code in the debugger to see if things actually work like you're expecting them to? I would have been doing that about 14 messages ago. :doh:

                    If you don't have the data, you're just another asshole with an opinion.

                    N Offline
                    N Offline
                    Naturality
                    wrote on last edited by
                    #27

                    Hmm.... xp is set to 4294967295 and does not change with each loop... y, however, does as is wanted.

                    "Sir, I protest. I am NOT a merry man!"

                    N 1 Reply Last reply
                    0
                    • N Naturality

                      Hmm.... xp is set to 4294967295 and does not change with each loop... y, however, does as is wanted.

                      "Sir, I protest. I am NOT a merry man!"

                      N Offline
                      N Offline
                      Naturality
                      wrote on last edited by
                      #28

                      Okay, fixed that. Still get the same output, though.

                      "Sir, I protest. I am NOT a merry man!"

                      1 Reply Last reply
                      0
                      • C Christian Graus

                        Yeah, I spotted that, too. But, I assume it is, if it were 32 bit, he'd be complaining about pixels not processed, I reckon.

                        Christian Graus Please read this if you don't understand the answer I've given you "also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

                        N Offline
                        N Offline
                        Naturality
                        wrote on last edited by
                        #29

                        Hmm.... I tried recreating the file using the other program(which uses the same values in bmp and bfh) using the CREATE_NEW definition in the CreateFile() function. When I do this, the resulting image cannot be drawn by windows picture and fax viewer. This may be the problem...

                        "Sir, I protest. I am NOT a merry man!"

                        T 2 Replies Last reply
                        0
                        • N Naturality

                          Hmm.... I tried recreating the file using the other program(which uses the same values in bmp and bfh) using the CREATE_NEW definition in the CreateFile() function. When I do this, the resulting image cannot be drawn by windows picture and fax viewer. This may be the problem...

                          "Sir, I protest. I am NOT a merry man!"

                          T Offline
                          T Offline
                          Tim Craig
                          wrote on last edited by
                          #30

                          Sounds like a clue to me. :suss: I'm not really up on that kind of file I/O. I rarely store things these days.

                          If you don't have the data, you're just another asshole with an opinion.

                          1 Reply Last reply
                          0
                          • N Naturality

                            Hmm.... I tried recreating the file using the other program(which uses the same values in bmp and bfh) using the CREATE_NEW definition in the CreateFile() function. When I do this, the resulting image cannot be drawn by windows picture and fax viewer. This may be the problem...

                            "Sir, I protest. I am NOT a merry man!"

                            T Offline
                            T Offline
                            Tim Craig
                            wrote on last edited by
                            #31

                            You've gone quiet. Did you ever get it to work? Inquiring minds want to know.

                            If you don't have the data, you're just another asshole with an opinion.

                            N 1 Reply Last reply
                            0
                            • T Tim Craig

                              You've gone quiet. Did you ever get it to work? Inquiring minds want to know.

                              If you don't have the data, you're just another asshole with an opinion.

                              N Offline
                              N Offline
                              Naturality
                              wrote on last edited by
                              #32

                              Unfortunately I haven't got it to work yet. I shall keep at it, however.

                              "Sir, I protest. I am NOT a merry man!"

                              1 Reply Last reply
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