Hi, I am just starting with numpy, pyhton and related others. I work on image processing basically. Now, my question is: what is the expected behaviour when slicing a view of an array? The following example might give some background on what I tried to do and the results obatined (which I don't understand): I read an image with PIL but, for whatever reason (different conventions I suppose), it comes upside down. This doesn't change when (I don't know the exact term for this) transforming the image to ndarray with 'array(img)'. I don't feel comfortable working with upside down images, so this had to be fixed. I tried to be smart and avoid copying the whole image: aimg = array(img)[::-1] and it worked!, but I am interested actually in sub-regions of this image, so the next I did was: roi = aimg[10:20,45:50,:] And to my surprise the result was like if I was slicing the original, upside down, image instead of aimg. Can someone explain me what's going on here? I searched and looked at the documentation but I couldn't find an answer. Maybe I am not looking properly. Is the only way to turn the image to perform a copy? Thanks, Jorge
participants (5)
-
Chris Colbert
-
Emmanuelle Gouillart
-
Jorge Scandaliaris
-
jorgesmbox-ml@yahoo.es
-
Pauli Virtanen