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copied!<p>I made this function which can see if an image exist within a bigger image. It is written as an extension, but can easily be modified to a normal function as well as supporting a region.</p> <p>To use it:</p> <ul> <li>Load main image into standard <code>Bitmap</code> as <code>bmp</code></li> <li>Load image to look for into <code>bmpSearch</code></li> </ul> <p>Then call:</p> <pre><code>Dim pt as Point = bmp.Contains(bmpSearch) If pt <> Nothing Then '... image found at pt End If </code></pre> <p>The code for the extension (room for optimizations, but written as a 20 minute exercise for another question on this site):</p> <pre><code>' '-- Extension for Bitmap ' <Extension()> Public Function Contains(src As Bitmap, ByRef bmp As Bitmap) As Point ' '-- Some logic pre-checks ' If src Is Nothing OrElse bmp Is Nothing Then Return Nothing If src.Width = bmp.Width AndAlso src.Height = bmp.Height Then If src.GetPixel(0, 0) = bmp.GetPixel(0, 0) Then Return New Point(0, 0) Else Return Nothing End If ElseIf src.Width < bmp.Width OrElse src.Height < bmp.Height Then Return Nothing End If ' '-- Prepare optimizations ' Dim sr As New Rectangle(0, 0, src.Width, src.Height) Dim br As New Rectangle(0, 0, bmp.Width, bmp.Height) Dim srcLock As BitmapData = src.LockBits(sr, Imaging.ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb) Dim bmpLock As BitmapData = bmp.LockBits(br, Imaging.ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb) Dim sStride As Integer = srcLock.Stride Dim bStride As Integer = bmpLock.Stride Dim srcSz As Integer = sStride * src.Height Dim bmpSz As Integer = bStride * bmp.Height Dim srcBuff(srcSz) As Byte Dim bmpBuff(bmpSz) As Byte Marshal.Copy(srcLock.Scan0, srcBuff, 0, srcSz) Marshal.Copy(bmpLock.Scan0, bmpBuff, 0, bmpSz) ' we don't need to lock the image anymore as we have a local copy bmp.UnlockBits(bmpLock) src.UnlockBits(srcLock) Dim x, y, x2, y2, sx, sy, bx, by, sw, sh, bw, bh As Integer Dim r, g, b As Byte Dim p As Point = Nothing bw = bmp.Width bh = bmp.Height sw = src.Width - bw ' limit scan to only what we need. the extra corner sh = src.Height - bh ' point we need is taken care of in the loop itself. bx = 0 : by = 0 ' '-- Scan source for bitmap ' For y = 0 To sh sy = y * sStride For x = 0 To sw sx = sy + x * 3 ' '-- Find start point/pixel ' r = srcBuff(sx + 2) g = srcBuff(sx + 1) b = srcBuff(sx) If r = bmpBuff(2) AndAlso g = bmpBuff(1) AndAlso b = bmpBuff(0) Then p = New Point(x, y) ' '-- We have a pixel match, check the region ' For y2 = 0 To bh - 1 by = y2 * bStride For x2 = 0 To bw - 1 bx = by + x2 * 3 sy = (y + y2) * sStride sx = sy + (x + x2) * 3 r = srcBuff(sx + 2) g = srcBuff(sx + 1) b = srcBuff(sx) If Not (r = bmpBuff(bx + 2) AndAlso g = bmpBuff(bx + 1) AndAlso b = bmpBuff(bx)) Then ' '-- Not matching, continue checking ' p = Nothing sy = y * sStride Exit For End If Next If p = Nothing Then Exit For Next End If 'end of region check If p <> Nothing Then Exit For Next If p <> Nothing Then Exit For Next bmpBuff = Nothing srcBuff = Nothing Return p End Function </code></pre>

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