Problems with ROI selection from scaled images

[Christian Saringer]

I experienced a problem with ROI selection when scaling the image from which to select the data from. In the source file ROI.py, line 2024/25 (pyqtgraph version 0.10.0) there is a rather inconclusive exception call in the getArrayRegion() method. Namely,

if br.width() > 1000:
    raise Exception()

Using the following line I scaled the image resulting in values that were obviously larger than that limit. 

img.scale(x_scale, y_scale)

After scaling, I tried to retrieve the data in the roi as shown in one of the examples:

def update():
 global z, img, roi
 arr = roi.getArrayRegion(z, img)


roi.sigRegionChanged.connect(update)

which resulting in the mentioned Exception. This only worked after commenting out the mentioned two lines in the source files. I assume this can be considered a bug because it worked also when I did not scale the image. 

Christian