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+---- Thread: Compare Images (/showthread.php?tid=1367)
Compare Images - SMcNeill - 01-04-2023
Code: (Select All)
'int memcmp(const void *str1, const void *str2, size_t n)
Declare CustomType Library
Function memcmp% (ByVal s1%&, Byval s2%&, Byval n As _Offset)
End Declare
Randomize Timer
Screen _NewImage(1280, 720, 32)
'let's make this an unique and pretty image!
For i = 1 To 100
Line (Rnd * _Width, Rnd * _Height)-(Rnd * width, Rnd * _Height), &HFF000000 + Rnd * &HFFFFFF, BF
Next
image2 = _CopyImage(0) 'identical copies for testing
image3 = _CopyImage(0) 'identical copy... BUT
_Dest image3
PSet (Rnd * _Width, Rnd * _Height), &HFF000000 + Rnd * &HFFFFFF 'We've just tweaked it so that there's no way in hell it's the same as the other two now!
_Dest 0 'image3 is EXACTLY one pixel different from the other two. Can we detect that?
image4 = _CopyImage(0) 'an identical copy once again, because 0 will change once we print the resul
result1 = CompareImages(0, image2)
result2 = CompareImages(0, image3)
result3 = CompareImages(image2, image3)
Print "Current Screen and Image 1 Compare: "; result1
Print "Current Screen and Image 2 Compare: "; result2
Print "Image1 and Image 2 Compare : "; result3
Print
Print "Press <ANY KEY> for a speed test!"
Sleep
t# = Timer
Limit = 1000
For i = 1 To Limit
result = CompareImages(image2, image3)
result = CompareImages(image2, image4)
Next
Print
Print Using "####.####### seconds to do"; Timer - t#;
Print Limit * 2; "comparisons."
Function CompareImages (handle1 As Long, handle2 As Long)
Static m(1) As _MEM
m(0) = _MemImage(handle1): m(1) = _MemImage(handle2)
If m(0).SIZE <> m(1).SIZE Then Exit Function 'not identical
If m(0).ELEMENTSIZE <> m(1).ELEMENTSIZE Then Exit Function 'not identical
If memcmp(m(0).OFFSET, m(1).OFFSET, m(0).SIZE) = 0 Then x = -1 Else x = 0
CompareImages = x
End FunctionCopied from deep inside another topic and shared here for ease of search and reference.
