On 18 November 2012 07:40, Alan Gauld <[email protected]> wrote: > On 16/11/12 17:40, Unaiza Ahsan wrote: > >> There is a function created for histogram equalization of images (called >> *histeq*), and saved in imtools.py. > > > >>>>> from PIL import Image >>>>> from numpy import * >>>>> im = array(Image.open('Tulips.jpg').convert('L')) >>>>> im2,cdf = imtools.histeq(im) >> >> >> I get this: >> >> Traceback (most recent call last): >> im2,cdf = imtools.histeq(im) >> File "C:\Python27\imtools.py", line 18, in histeq >> imhist,bins = histogram(im.flatten(),nbr_bins,normed=True) >> NameError: global name 'histogram' is not defined > > > This tells us that the name histogram is not defined > in the imtools.py file. Is it one of the modules ytou show imported above? > If so it will not be visible inside imtools.py. You need to import the > required module in that file too. > > But that's just a guess... > > >> And the relevant portion in imtools.py is: >> def histeq(im,nbr_bins=256): >> """ Histogram equalization of a grayscale image. """ >> >> #get image histogram >> imhist,bins = histogram(im.flatten(),nbr_bins,normed=True) > > > This is the call, but where is histogram? If it is in imtools are you sure > the spelling is correct? If its not there you need to import it from > wherever it is defined. > > HTH > -- > Alan G > Author of the Learn to Program web site > http://www.alan-g.me.uk/ > > > _______________________________________________ > Tutor maillist - [email protected] > To unsubscribe or change subscription options: > http://mail.python.org/mailman/listinfo/tutor
Hi all, The function histogram is supposed to come from the numpy module; at least that's the case on my computer (I have numpy 1.6.2 for Python 2.7): >>> from numpy import * >>> histogram <function histogram at 0x10b0c0ed8> Maybe something is wrong with Unaiza's version of numpy. Kal _______________________________________________ Tutor maillist - [email protected] To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
