"Jerry Hill" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Hello all,
>
> I have a piece of code I could use some help optimizing. What I'm
> attempting to do is periodically grab a screenshot, and search for 2D
> patterns of black pixels in it. I don't care about any color other
> than black. Here's some simple code that simulates my worst-case
> scenario, scanning the whole screen for a sequence that does not
> exist:
>
> import ImageGrab # From the PIL library
>
> def removeColor(rgb):
> r, g, b = rgb
> return (r == 0 and g == 0 and b == 0)
>
> BMP = ImageGrab.grab.getdata()
> x = map(removeColor, BMP)
>
> The idea is to search for sequences of black pixels on a background
> that can change colors.
I had to do a similar thing using pywinauto to interact with a IE browser
running an embedded Flash application. To speed things up, I included psyco
to compile my functions.
As far as working just in Python, you could remove the tuple unpacking
inside removeColor, and shorten it to just:
def removeColor(rgb):
return rgb==(0,0,0)
or even better:
BLACK = (0,0,0)
def removeColor(rgb):
return rgb==BLACK
By defining BLACK once and just referring to it by name, you also avoid
dynamically constructing the (0,0,0) tuple in every call.
But you might also look at the PIL docs and see if there is a way to do this
color manipulation using the PIL API - the advantage here is that then you
would be invoking a C-compiled API routine, which will run way faster than
any optimized Python method.
-- Paul
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