gistfile1.c

for (i = 0; i < LENGTH(iImage->Pixels); i++) 
	{
		pixel = pos = 0;

		for (row = -(m - 1)/2.0; row <= (m - 1)/2.0; row++)
		{
			for (col = -(m - 1)/2.0; col <= (m - 1)/2.0; col++)
			{
				pos = i + row * iImage->Width + col;
				if (pos >= 0 && pos <= lastPixel) // Check for top and bottom
				{
					if (i % iImage->Width == 0 && (pos + 1) % iImage->Width != 0) // check left
					{
						pixel += F[row][col] * iImage->Pixels[pos];
					}
					else if ( (i + 1) % iImage->Width == 0 && pos % iImage->Width != 0) // check right
					{
						pixel += F[row][col] * iImage->Pixels[pos];
					}
				}
			}
		}

		oImage->Pixels[i] = pixel / normalization;
		return TRUE;
	}