Method Reference
PixelChecksum
Generates a checksum for a region of pixels
PixelChecksum left, top, right, bottom [, step]
Parameters
| left | left coordinate of rectangle. |
| top | top coordinate of rectangle. |
| right | right coordinate of rectangle. |
| bottom | bottom coordinate of rectangle. |
| step | Optional: Instead of checksumming each pixel use a value larger than 1 to skip pixels (for speed). E.g. A value of 2 will only check every other pixel. Default is 1. |
Return Value
Returns the checksum value of the region.Remarks
Performing a checksum of a region is very time consuming, so use the smallest region you are able to reduce CPU load. On some machines a checksum of the whole screen could take many seconds!
A checksum only allows you to see if "something" has changed in a region - it does not tell you exactly what has changed.
When using a step value greater than 1 you must bear in mind that the checksumming becomes less reliable for small changes as not every pixel is checked.
Related
PixelChecksum, PixelCoordMode (Option), PixelGetColor, PixelSearch
Example
Set oAutoIt = WScript.CreateObject("AutoItX3.Control") ' Get initial checksum checksum = oAutoIt.PixelChecksum(0,0, 50,50)