Check the inverse of the numbers, there are a ton of inconsistencies
of x,y and matrix representation. Basically an image's x axis
progresses left to right, whereas a matrix's x is top to bottom (x,y
versus row,column). So check 2,3 and 3,2 on GIMP, etc.
On Thu, Oct 28, 2010 at 12:56 PM, German Ocampo <geroca...@gmail.com> wrote:
> Chris
>
> Many thanks for your email.I want to read values from images in
> grayscale or rgb, because the product that is coming from Arcmap could
> be either.
>
> The issue is that using PIL I get pixel values in the greyscale of 127
> or rgb(0,0,0), where really I could see in Gimp that these pixels have
> a different value. Looks like PIL can decode part of the picture and
> another part of the picture not.
>
> Also I tried today to read the pixel values of the picture using
> temp=np.array(im) but still I got some cells with a value of 127
> where really the image has different values.
>
> The only way to decode the picture was using freeImagepy, opening the
> image with freeImagepy, saving and then open again with PIL to get the
> values. It works but not in the way that supose to be. I want to do
> all with PIL :-)
> (Attached is the code)
>
> Many thanks
>
> German
>
> from PIL import Image
> from PIL import TiffImagePlugin
> import numpy as np
> import sys
> import FreeImagePy
> FIPY = FreeImagePy.freeimage()
> image = FIPY.genericLoader(file_tif)
> FIPY.Save(FreeImagePy.FIF_TIFF, image, "temp.tif")
>
> im = Image.open("temp.tif")
> values=np.zeros((size_y,size_x))
> mode=im.mode
> temp=list(im.getdata())
> cont=-1
> list_colors=[]
> for i in range(0,size_y):
> for j in range(0,size_x):
> cont+=1
> if mode=="RGB":
> color=temp[cont]
> print cont,temp[cont]
> if color in list_colors:
> index=list_colors.index(color)
> values[i][j]=index+1
> else:
> list_colors.append(color)
> values[i][j]=len(list_colors)
> else:
> values[i][j]=temp[cont]
>
> On Thu, Oct 28, 2010 at 4:26 PM, Chris Mitchell <chris.m...@gmail.com> wrote:
>> Why would the image go between greyscale and rgb? In anycase, perhaps
>> the easiest solution is use np.resize on temp instead of the for
>> loops. Then if you have tuples of rgb versus ints you can use
>> np.where()
>>
>> On Thu, Oct 28, 2010 at 4:36 AM, German Ocampo <geroca...@gmail.com> wrote:
>>> Good morning
>>>
>>> Im reading an 8bit image generated by ArcMap using PIL in windows, the
>>> image load well without error messages but, when I try to extract the
>>> values to a numpy array I got some lines of the image with value of
>>> pixel 127 (greyscale) or rgb(0,0,0). When I open the image using GIMP
>>> or arcmap I could see that the image is complete.
>>>
>>> Any idea of what is happening??
>>>
>>> the code that I'm using for read the image is:
>>>
>>> from PIL import Image
>>> from PIL import TiffImagePlugin
>>> import numpy as np
>>> import sys
>>> im = Image.open(file_tif)
>>> values=np.zeros((size_y,size_x))
>>> mode=im.mode
>>> temp=list(im.getdata())
>>> cont=-1
>>> list_colors=[]
>>> for i in range(0,size_y):
>>> for j in range(0,size_x):
>>> cont+=1
>>> if mode=="RGB":
>>> color=temp[cont]
>>> print cont,temp[cont]
>>> if color in list_colors:
>>> index=list_colors.index(color)
>>> values[i][j]=index+1
>>> else:
>>> list_colors.append(color)
>>> values[i][j]=len(list_colors)
>>> else:
>>> values[i][j]=temp[cont]
>>>
>>> Best regards
>>>
>>> German
>>> _______________________________________________
>>> Image-SIG maillist - image-...@python.org
>>> http://mail.python.org/mailman/listinfo/image-sig
>>>
>>
>
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