CANNY算法源码

这是[精通VC图像处理（第三版）光盘]的canny算法部分,采用的是模板的方式

我找了很久,需要其它函数,到第二版或者网上找找吧,肯定能找到

#define HDIB HANDLE
#define PI 3.1415926

/**//************************************************************************* 
 * GausianFilterDIB
 * 
 * Parameters: 
 *        HDIB hDIB        - handle to global memory with a DIB spec 
 *                            in it followed by the DIB bits 
 * Return Value: 
 *        BOOL             - TRUE is success, else FALSE
 * Description: 
 *        Process Gausian filtering
 ************************************************************************/ 
BOOL GausianFilterDIB(HDIB hDib)
...{
    unsigned char mask[5][5];
    int r, c, i, j;
    int SUM;

//    WaitCursorBegin();

    // 5x5 Gaussian mask
    mask[0][0] = 2; mask[0][1] =  4; mask[0][2] =  5; mask[0][3] =  4; mask[0][4] = 2;
    mask[1][0] = 4; mask[1][1] =  9; mask[1][2] = 12; mask[1][3] =  9; mask[1][4] = 4;
    mask[2][0] = 5; mask[2][1] = 12; mask[2][2] = 15; mask[2][3] = 12; mask[2][4] = 5;
    mask[3][0] = 4; mask[3][1] =  9; mask[3][2] = 12; mask[3][3] =  9; mask[3][4] = 4;
    mask[4][0] = 2; mask[4][1] =  4; mask[4][2] =  5; mask[4][3] =  4; mask[4][4] = 2;

    // copy to a new DIB to store original data
    HDIB hNewDib = CopyHandle(hDib);
    if (! hNewDib)
    ...{
//        WaitCursorEnd();
        return FALSE;
    }

    // new DIB attributes
    WORD wDIBWidth = (WORD)DIBWidth(hNewDib);
    WORD wDIBHeight = (WORD)DIBHeight(hNewDib);
    WORD wBytesPerLine = (WORD)BytesPerLine(hNewDib);

    // original DIB become dest image
    LPBYTE lpDestDIB = (LPBYTE)GlobalLock(hDib);
    LPBYTE lpDestImage = FindDIBBits(lpDestDIB);

    // get bits address in DIB
    LPBYTE lpDIB = (LPBYTE)GlobalLock(hNewDib);
    LPBYTE lpDIBits = FindDIBBits(lpDIB);

    for(r=0; r<wDIBHeight; r++)
    ...{
        for(c=0; c<wDIBWidth ; c++)
        ...{
            SUM=0;

            long lOffset = PIXEL_OFFSET(r,c, wBytesPerLine);

            if(r==0 || r==1 || r==wDIBHeight-2 || r==wDIBHeight-1)
                SUM =  *(lpDIBits + lOffset);
            else if(c==0 || c==1 || c==wDIBWidth-2 || c==wDIBWidth-1)
                SUM =  *(lpDIBits + lOffset);
                 
            // Convolution starts here
            else   
            ...{
                for(i=-2; i<=2; i++)  
                ...{
                    for(j=-2; j<=2; j++)  
                    ...{
                        lOffset = PIXEL_OFFSET(r+i,c+j, wBytesPerLine);
                        SUM = SUM + (int)(*(lpDIBits + lOffset) * mask[i+2][j+2]/115);
                    }
                }
            }

            if(SUM>255)  
                SUM=255;
            if(SUM<0)    
                SUM=0;

            lOffset = PIXEL_OFFSET(r,c, wBytesPerLine);
            *(lpDestImage + lOffset) = (unsigned char)(SUM);
        }
    }

    // cleanup temp buffers
    GlobalUnlock(hNewDib);
    GlobalFree(hNewDib);
    GlobalUnlock(hDib);
    
    WaitCursorEnd();
    return TRUE;
}


/**//************************************************************************* 
 * CannyEdegeDetectDIB() 
 * 
 * Parameters: 
 *        HDIB hDIB        - handle to global memory with a DIB spec 
 *                            in it followed by the DIB bits 
 * Return Value: 
 *        BOOL             - TRUE is success, else FALSE
 * Description: 
 *        Difference Edege Detect DIB
 ************************************************************************/ 
BOOL CannyEdegeDetectDIB(HDIB hDib) 
...{
    int GX[3][3], GY[3][3];
    int sumX, sumY, SUM;
    int r,c, i, j;
    double ORIENT;
    int    edgeDirection;
    int    highThreshold, lowThreshold;
    int    leftPixel, rightPixel;
    int    P1, P2, P3, P4, P5, P6, P7, P8;
    long lOffset;

    WaitCursorBegin();

    // 1. convert to gray scale
    ConvertToGrayscale(hDib, MEAN_GRAY, 0, 0, 0);

    // 2. Gausian Filter DIB
    if (! GausianFilterDIB(hDib))
    ...{
        WaitCursorEnd();
        return FALSE;
    }

    // 3. process...

    // 3x3 GX Sobel mask.  Ref: www.cee.hw.ac.uk/hipr/html/sobel.html 
    GX[0][0] = -1; GX[0][1] = 0; GX[0][2] = 1;
    GX[1][0] = -2; GX[1][1] = 0; GX[1][2] = 2;
    GX[2][0] = -1; GX[2][1] = 0; GX[2][2] = 1;

    // 3x3 GY Sobel mask.  Ref: www.cee.hw.ac.uk/hipr/html/sobel.html 
    GY[0][0] =  1; GY[0][1] =  2; GY[0][2] =  1;
    GY[1][0] =  0; GY[1][1] =  0; GY[1][2] =  0;
    GY[2][0] = -1; GY[2][1] = -2; GY[2][2] = -1;

    // copy to a new DIB to store original data
    HDIB hNewDib = CopyHandle(hDib);
    if (! hNewDib)
    ...{
        WaitCursorEnd();
        return FALSE;
    }

    // new DIB attributes
    WORD wDIBWidth = (WORD)DIBWidth(hNewDib);
    WORD wDIBHeight = (WORD)DIBHeight(hNewDib);
    WORD wBytesPerLine = (WORD)BytesPerLine(hNewDib);

    // original DIB become dest image
    LPBYTE lpDestDIB = (LPBYTE)GlobalLock(hDib);
    LPBYTE lpDestImage = FindDIBBits(lpDestDIB);

    // get bits address in DIB
    LPBYTE lpDIB = (LPBYTE)GlobalLock(hNewDib);
    LPBYTE lpDIBits = FindDIBBits(lpDIB);

    for(r=0; r<wDIBHeight; r++)
    ...{
        for(c=0; c<wDIBWidth; c++)
        ...{
            sumX = 0;
            sumY = 0;

            // image boundaries
            if(r==0 || r==wDIBHeight-1)
                SUM = 0;
            else if(c==0 || c==wDIBWidth-1)
                SUM = 0;

            // Convolution starts here
            else   
            ...{
                /**//***********************************
                * X gradient approximation
                ***********************************/
                for(i=-1; i<=1; i++)  
                ...{
                    for(j=-1; j<=1; j++)  
                    ...{
                        lOffset = PIXEL_OFFSET(r+i,c+j, wBytesPerLine);
                        sumX = sumX + (int)(*(lpDIBits + lOffset) * GX[i+1][j+1]);
                    }
                }

                /**//**************************
                * Y gradient approximation
                **************************/
                for(i=-1; i<=1; i++)  
                ...{
                    for(j=-1; j<=1; j++)  
                    ...{
                        lOffset = PIXEL_OFFSET(r+i,c+j, wBytesPerLine);
                        sumY = sumY + (int)(int)(*(lpDIBits + lOffset) * GY[i+1][j+1]);
                    }
                }

                /**//***********************************************
                * GRADIENT MAGNITUDE APPROXIMATION (Myler p.218)
                ***********************************************/
                SUM = abs(sumX) + abs(sumY);

                if(SUM>255)    
                    SUM=255;
                if(SUM<0)      
                    SUM=0;
            }

            /**//***************************
            * Magnitude orientation
            ***************************/
            /**//* Cannot divide by zero*/
            if(sumX == 0)   
            ...{
                if(sumY==0) 
                    ORIENT = 0.0;
                else if (sumY<0)   
                ...{
                    sumY = -sumY;

                    ORIENT = 90.0;
                }
                else 
                    ORIENT = 90.0;
            }

            // Can't take invtan of angle in 2nd Quad
            else if(sumX<0 && sumY>0)   
            ...{
                sumX = -sumX;
                ORIENT = 180 - ((atan((float)(sumY)/(float)(sumX))) * (180/PI));
            }

            // Can't take invtan of angle in 4th Quad
            else if(sumX>0 && sumY<0)   
            ...{
                sumY = -sumY;
                ORIENT = 180 - ((atan((float)(sumY)/(float)(sumX))) * (180/PI));
            }

            // else angle is in 1st or 3rd Quad
            else 
                ORIENT = (atan((float)(sumY)/(float)(sumX))) * (180/PI);


            /**//***************************************************
            * Find edgeDirection by assigning ORIENT a value of
            * either 0, 45, 90 or 135 degrees, depending on which
            * value ORIENT is closest to
            ****************************************************/
            if(ORIENT < 22.5) 
                edgeDirection = 0;
            else if(ORIENT < 67.5) 
                edgeDirection = 45;
            else if(ORIENT < 112.5) 
                edgeDirection = 90;
            else if(ORIENT < 157.5) 
                edgeDirection = 135;
            else 
                edgeDirection = 0;

            /**//***************************************************
            * Obtain values of 2 adjacent pixels in edge
            * direction.
            ****************************************************/
            if(edgeDirection == 0)   
            ...{
                lOffset = PIXEL_OFFSET(r,c-1, wBytesPerLine);
                leftPixel = (int)(*(lpDIBits + lOffset));
                lOffset = PIXEL_OFFSET(r,c+1, wBytesPerLine);
                rightPixel = (int)(*(lpDIBits + lOffset));
            }

            else if(edgeDirection == 45)   
            ...{
                lOffset = PIXEL_OFFSET(r+1,c-1, wBytesPerLine);
                leftPixel = (int)(*(lpDIBits + lOffset));
                lOffset = PIXEL_OFFSET(r+1,c+1, wBytesPerLine);
                rightPixel = (int)(*(lpDIBits + lOffset));
            }

            else if(edgeDirection == 90)   
            ...{
                lOffset = PIXEL_OFFSET(r-1,c, wBytesPerLine);
                leftPixel = (int)(*(lpDIBits + lOffset));
                lOffset = PIXEL_OFFSET(r+1,c, wBytesPerLine);
                rightPixel = (int)(*(lpDIBits + lOffset));
            }

            else   
            ...{
                lOffset = PIXEL_OFFSET(r-1,c-1, wBytesPerLine);
                leftPixel = (int)(*(lpDIBits + lOffset));
                lOffset = PIXEL_OFFSET(r-1,c+1, wBytesPerLine);
                rightPixel = (int)(*(lpDIBits + lOffset));
            }

            /**//*********************************************
            * Compare current magnitude to both adjacent
            * pixel values.  And if it is less than either
            * of the 2 adjacent values - suppress it and make
            * a nonedge.
            *********************************************/

            if(SUM < leftPixel || SUM < rightPixel) 
                SUM = 0;
            else   
            ...{
                /**//**********************
                * Hysteresis
                **********************/
                 highThreshold = 120;
                 lowThreshold = 40;

                 lOffset = PIXEL_OFFSET(r,c, wBytesPerLine);
                 if(SUM >= highThreshold)
                       SUM = *(lpDIBits + lOffset); // edge
                 else if(SUM < lowThreshold)
                     SUM = 0;  // nonedge

                 // SUM is between T1 & T2
                 else   
                 ...{
                    // Determine values of neighboring pixels
                    lOffset = PIXEL_OFFSET(r-1,c-1, wBytesPerLine);
                    P1 = (int)*(lpDIBits + lOffset);
                    lOffset = PIXEL_OFFSET(r-1,c, wBytesPerLine);
                    P2 = (int)*(lpDIBits + lOffset);
                    lOffset = PIXEL_OFFSET(r-1,c+1, wBytesPerLine);
                    P3 = (int)*(lpDIBits + lOffset);
                    lOffset = PIXEL_OFFSET(r,c-1, wBytesPerLine);
                    P4 = (int)*(lpDIBits + lOffset);
                    lOffset = PIXEL_OFFSET(r,c+1, wBytesPerLine);
                    P5 = (int)*(lpDIBits + lOffset);
                    lOffset = PIXEL_OFFSET(r+1,c-1, wBytesPerLine);
                    P6 = (int)*(lpDIBits + lOffset);
                    lOffset = PIXEL_OFFSET(r+1,c, wBytesPerLine);
                    P7 = (int)*(lpDIBits + lOffset);
                    lOffset = PIXEL_OFFSET(r+1,c+1, wBytesPerLine);
                    P8 = (int)*(lpDIBits + lOffset);

                    // Check to see if neighboring pixel values are edges
                    lOffset = PIXEL_OFFSET(r,c, wBytesPerLine);
                    if( P1 > highThreshold || P2 > highThreshold || 
                        P3 > highThreshold || P4 > highThreshold || 
                        P5 > highThreshold || P6 > highThreshold || 
                        P7 > highThreshold || P8 > highThreshold)
                        SUM = *(lpDIBits + lOffset); // make edge
                    else 
                        SUM = 0; // make nonedge
                }
            }

            lOffset = PIXEL_OFFSET(r,c, wBytesPerLine);
            *(lpDestImage + lOffset) =  (BYTE)(SUM);
        }
    }

    // cleanup temp buffers
    GlobalUnlock(hNewDib);
    GlobalFree(hNewDib);
    GlobalUnlock(hDib);
    
    WaitCursorEnd();
    return TRUE;
}