i get this error
public static Rectangle searchBitmap( Bitmap smallBmp, Bitmap bigBmp)
{
BitmapData smallData = smallBmp.LockBits(new Rectangle(0, 0, smallBmp.Width, smallBmp.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
BitmapData bigData = bigBmp.LockBits(new Rectangle(0, 0, bigBmp.Width, bigBmp.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
int smallStride = smallData.Stride;
int bigStride = bigData.Stride;
int bigWidth = bigBmp.Width;
int bigHeight = bigBmp.Height - smallBmp.Height + 1;
int smallWidth = smallBmp.Width * 3;
int smallHeight = smallBmp.Height;
Rectangle location = Rectangle.Empty;
int margin = Convert.ToInt32(255.0 * 0);
unsafe
{
byte* pSmall = (byte*)(void*)smallData.Scan0;
byte* pBig = (byte*)(void*)bigData.Scan0;
int smallOffset = smallStride - smallBmp.Width * 3;
int bigOffset = bigStride - bigBmp.Width * 3;
bool matchFound = true;
for (int y = 0; y < bigHeight; y++)
{
for (int x = 0; x < bigWidth; x++)
{
byte* pBigBackup = pBig;
byte* pSmallBackup = pSmall;
//Look for the small picture.
for (int i = 0; i < smallHeight; i++)
{
int j = 0;
matchFound = true;
for (j = 0; j < smallWidth; j++)
{
//With tolerance: pSmall value should be between margins.
int inf = pBig[0] - margin;
int sup = pBig[0] + margin;
if (sup < pSmall[0] || inf > pSmall[0])
{
matchFound = false;
break;
}
pBig++;
pSmall++;
}
if (!matchFound) break;
//We restore the pointers.
pSmall = pSmallBackup;
pBig = pBigBackup;
//Next rows of the small and big pictures.
pSmall += smallStride * (1 + i);
pBig += bigStride * (1 + i);
}
//If match found, we return.
if (matchFound)
{
location.X = x;
location.Y = y;
location.Width = smallBmp.Width;
location.Height = smallBmp.Height;
break;
}
//If no match found, we restore the pointers and continue.
else
{
pBig = pBigBackup;
pSmall = pSmallBackup;
pBig += 3;
}
}
if (matchFound) break;
pBig += bigOffset;
}
}
bigBmp.UnlockBits(bigData);
smallBmp.UnlockBits(smallData);
return location;
}
