I have a simple test function (histogram), this use a TestForm class 
which is a subclass of ColorForm (see enclosed TestForm.zip).

If I run histogram1 (which use 'self pixelValueAt: x at y') I obtain 
Hist1.png, then I run histogram2 (with 'peeker pixelAt: x at y')
and obtain Hist2.png, these histograms are different, but with 
histogram3 which add the line 'self colors: nil.' I obtain Hist1.png 
again.

I don't understand why, because pixelValueAt: is defined as:
	^ (BitBlt current bitPeekerFromForm: self) pixelAt: aPoint

apart from the extra overhead of calling 'BitBlt current 
bitPeekerFromForm:' for each pixel, I think is the same, so what is the 
problem?

This is a 3.4 image (updated to 5170) with the 'Squeak 3.5.1Beta4' 
MacOSX VM.

Javier Diaz-Reinoso
Web: http://homepage.mac.com/javier_diaz_r/
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