I've been working on a script, and I need it to basically:
- Make the image greyscale (or bitonal, I will play with both to see which one works better).
- Process each individual column and create a net intensity value for each column.
- Spit the results into an ordered list.
There is a really easy way to do this with ImageMagick (although you need a few Linux utilities to process the output text), but I'm not really seeing how to do this with Python and PIL.
Here's what I have so far:
from PIL import Image
image_file = 'test.tiff'
image = Image.open(image_file).convert('L')
histo = image.histogram()
histo_string = ''
for i in histo:
histo_string += str(i) + "\n"
print(histo_string)
This outputs something (I am looking to graph the results), but it looks nothing like the ImageMagick output. I'm using this to detect the seam and content of a scanned book.
Thanks to anyone who helps!
I've got a (nasty-looking) solution that works, for now:
from PIL import Image
import numpy
def smoothListGaussian(list,degree=5):
window=degree*2-1
weight=numpy.array([1.0]*window)
weightGauss=[]
for i in range(window):
i=i-degree+1
frac=i/float(window)
gauss=1/(numpy.exp((4*(frac))**2))
weightGauss.append(gauss)
weight=numpy.array(weightGauss)*weight
smoothed=[0.0]*(len(list)-window)
for i in range(len(smoothed)):
smoothed[i]=sum(numpy.array(list[i:i+window])*weight)/sum(weight)
return smoothed
image_file = 'verypurple.jpg'
out_file = 'out.tiff'
image = Image.open(image_file).convert('1')
image2 = image.load()
image.save(out_file)
intensities = []
for x in xrange(image.size[0]):
intensities.append([])
for y in xrange(image.size[1]):
intensities[x].append(image2[x, y] )
plot = []
for x in xrange(image.size[0]):
plot.append(0)
for y in xrange(image.size[1]):
plot[x] += intensities[x][y]
plot = smoothListGaussian(plot, 10)
plot_str = ''
for x in range(len(plot)):
plot_str += str(plot[x]) + "\n"
print(plot_str)