public static ImageElement FindImageElement(Bitmap smallBmp, double accuracy)
{
FormsHelper.HideAllForms();
dynamic element = null;
double tolerance = 1.0 - accuracy;
Bitmap bigBmp = ImageMethods.Screenshot();
Bitmap smallTestBmp = new Bitmap(smallBmp);
Bitmap bigTestBmp = new Bitmap(bigBmp);
Graphics bigTestGraphics = Graphics.FromImage(bigTestBmp);
BitmapData smallData =
smallBmp.LockBits(new Rectangle(0, 0, smallBmp.Width, smallBmp.Height),
ImageLockMode.ReadOnly,
PixelFormat.Format24bppRgb);
BitmapData bigData =
bigBmp.LockBits(new Rectangle(0, 0, bigBmp.Width, bigBmp.Height),
ImageLockMode.ReadOnly,
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;
int margin = Convert.ToInt32(255.0 * tolerance);
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)
{
element = new ImageElement
{
LeftX = x,
MiddleX = x + smallBmp.Width / 2,
RightX = x + smallBmp.Width,
TopY = y,
MiddleY = y + smallBmp.Height / 2,
BottomY = y + 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);
bigTestGraphics.Dispose();
return(element);
}
