/*----------------------------------------------------------------------------*/
void image_pan(my1Image *image, my1Image *result, int shx, int shy, int vin)
{
int iloop, jloop;
int calcx, calcy, calcv;
int row = image->height, col = image->width;
/* calculate new pixel index */
for(iloop=0;iloop<row;iloop++)
{
for(jloop=0;jloop<col;jloop++)
{
calcx = jloop - shx;
calcy = iloop - shy;
if(calcx>=0&&calcx<col&&calcy>=0&&calcy<row)
{
calcv = imagepixel(image,calcy,calcx);
setimagepixel(result,iloop,jloop,calcv);
}
else
{
setimagepixel(result,iloop,jloop,vin);
}
}
}
}
/*----------------------------------------------------------------------------*/
int sobel_image(my1Image *src, my1Image *dst_mag, my1Image *dst_ang)
{
my1Image buff1, buff2;
int irow, icol, x, y, temp;
// create temporary buffer
if(!createimage(&buff1,src->height,src->width))
{
//printf("Cannot allocate buff1 memory\n");
return -1;
}
if(!createimage(&buff2,src->height,src->width))
{
freeimage(&buff1);
//printf("Cannot allocate buff2 memory\n");
return -1;
}
// calculate directional edge
sobel_x_image(src, &buff1);
sobel_y_image(src, &buff2);
// calculate angle for 3x3 neighbourhood
for(irow=0;irow<src->height;irow++)
{
for(icol=0;icol<src->width;icol++)
{
x = imagepixel(&buff1,irow,icol);
y = imagepixel(&buff2,irow,icol);
setimagepixel(dst_mag,irow,icol,iabs(y)+iabs(x));
if(!dst_ang) continue;
if(x>0)
{
if(y>0)
{
// q1
y = iabs(y); x = iabs(x);
if(y>2*x) temp = 90;
else if(x>2*y) temp = 0;
else temp = 45;
}
else if(y<0)
{
// q4
y = iabs(y); x = iabs(x);
if(y>2*x) temp = 270;
else if(x>2*y) temp = 0;
else temp = 315;
}
else
{
temp = 0; // +ve x-axis
}
}
else if(x<0)
{
if(y>0)
{
// q2
y = iabs(y); x = iabs(x);
if(y>2*x) temp = 90;
else if(x>2*y) temp = 180;
else temp = 135;
}
else if(y<0)
{
// q3
y = iabs(y); x = iabs(x);
if(y>2*x) temp = 270;
else if(x>2*y) temp = 180;
else temp = 225;
}
else
{
temp = 180; // -ve x-axis
}
}
else
{
if(y>0)
{
temp = 90; // +ve y-axis
}
else if(y<0)
{
temp = 270; // -ve y-axis
}
else
{
temp = 0; // origin! no edge?
}
}
setimagepixel(dst_ang,irow,icol,temp);
}
}
/* clean-up */
freeimage(&buff1);
freeimage(&buff2);
return 0;
}
