ssyyjj88 / simple-iphone-image-processing

Automatically exported from code.google.com/p/simple-iphone-image-processing
0 stars 0 forks source link

Gaussian blur bug #5

Open GoogleCodeExporter opened 8 years ago

GoogleCodeExporter commented 8 years ago
What steps will reproduce the problem?
1. Improve gaussianBlur() or take my improved code
2.
3.

What is the expected output? What do you see instead?
gaussianBlur() reduces image by 5 pixels in the upper left corner.

What version of the product are you using? On what operating system?
xCode and the newest version (13th july 2010)

Please provide any additional information below.
Fixed gaussianBlur() function:

ImageWrapper *Image::gaussianBlur() {
    Image *result=new Image(m_width, m_height);
    for(int y = 0; y < m_height; y++) {
        for(int x = 0; x < m_width; x++) {

            int val = (*this)[y][x]*41; //Declare currents pixels value
            int middle = 41; //Declare average

            if (x > 0)                          { val += (*this)[y][x-1]    *26;middle += 26;}
            if (x > 1)                          { val += (*this)[y][x-2]    *7; middle += 7;}
            if (x < m_width-1)                  { val += (*this)[y][x+1]    *26;middle += 26;}
            if (x < m_width-2)                  { val += (*this)[y][x+2]    *7; middle += 7;}

            if (y > 0)                          { val += (*this)[y-1][x]    *26;middle += 26;}
            if (y > 0 && x > 0)                 { val += (*this)[y-1][x-1]  *16;middle += 16;}
            if (y > 0 && x > 1)                 { val += (*this)[y-1][x-2]  *4; middle += 4;}
            if (y > 0 && x < m_width-1)         { val += (*this)[y-1][x+1]  *16;middle += 16;}
            if (y > 0 && x < m_width-2)         { val += (*this)[y-1][x+2]  *4; middle += 4;}

            if (y > 1)                          { val += (*this)[y-2][x]    *7; middle += 7;}
            if (y > 1 && x > 0)                 { val += (*this)[y-2][x-1]  *4; middle += 4;}
            if (y > 1 && x > 1)                 { val += (*this)[y-2][x-2]  *1; middle += 1;}
            if (y > 1 && x < m_width-1)         { val += (*this)[y-2][x+1]  *4; middle += 4;}
            if (y > 1 && x < m_width-2)         { val += (*this)[y-2][x+2]  *1; middle += 1;}

            if (y < m_height-1)                 { val += (*this)[y+1][x]    *26;middle += 26;}
            if (y < m_height-1 && x > 0)        { val += (*this)[y+1][x-1]  *16;middle += 16;}
            if (y < m_height-1 && x > 1)        { val += (*this)[y+1][x-2]  *4; middle += 4;}
            if (y < m_height-1 && x < m_width-1){ val += (*this)[y+1][x+1]  *16;middle += 16;}
            if (y < m_height-1 && x < m_width-2){ val += (*this)[y+1][x+2]  *4; middle += 4;}

            if (y < m_height-2)                 { val += (*this)[y+2][x]    *7; middle += 7;}
            if (y < m_height-2 && x > 0)        { val += (*this)[y+2][x-1]  *4; middle += 4;}
            if (y < m_height-2 && x > 1)        { val += (*this)[y+2][x-2]  *1; middle += 1;}
            if (y < m_height-2 && x < m_width-1){ val += (*this)[y+2][x+1]  *4; middle += 4;}
            if (y < m_height-2 && x < m_width-2){ val += (*this)[y+2][x+2]  *1; middle += 1;}

            (*result)[y][x] = (int)val/middle; //Calculating average value for given pixel
        }
    }

    return [ImageWrapper imageWithCPPImage:result]; //Return the image
}

Original issue reported on code.google.com by Me.Te...@gmail.com on 13 Jul 2010 at 7:10

GoogleCodeExporter commented 8 years ago
+1 to this issue too, just ran into it myself and was surprised that the blur 
function would reduce the size of the image.

Original comment by t...@google.com on 28 Mar 2011 at 1:05