How to locate a pixels position?

Thekid

How can I locate a particular pixel in an image? I need to find 'odd' pixels counts, which I can do but I don't know how to get that particular pixel ( if that makes sense):

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from PIL import Image
 
i = Image.open('Img.bmp')

for pixel in i.getdata():

    if pixel [2] > 0:

        print pixel

That will print out just the ones I want instead of every pixel count in the image and the results are like this:

(77, 0, 8)
(89, 0, 8)
(41, 0, 10)
(50, 0, 7)
(42, 0, 5)
(55, 0, 9)
(112, 0, 5)
(105, 0, 9)

So in this instance I would need the pixel positions of the 3rd numbers in the R,G,B lists.

bvdet

I don't understand your question. You can determine a particular pixel with the getpixel((col,row)) method.

Thekid

Let's say I have a red image that has 8 blue pixels scattered through out it. If I run the code so it prints out like above, it verifies that they were found, but I don't know how to 'locate' them or find their x,y positions in the image. I'm trying to google getpixel((col,row)), it seems that may be what I want I just don't know how to implement it.

bvdet

Set the upper and lower limits of the pixels you want to find. The following is geared toward red.

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 from PIL import Image

import operator
 
img = Image.open(r'D:\Miscellaneous\BVLogo.png')
 
# List the pixels having RGB values in defined range
 
upper = (255,50,50)

lower = (200,0,0)
 
output = []
 
for col in range(img.size[0]):

    for row in range(img.size[1]):

        pixel = img.getpixel((col,row))

        if False not in map(operator.lt,lower,pixel) \

        and False not in map(operator.gt,upper,pixel):

            output.append((col,row))
 
for pixel in output:

    print pixel

Thekid

I've tried the suggested code but can't seem to get it to work. I even tried switching around the R,G,B values but still nothing. Here's an example image for what I'm using:
http://img404.imageshack.us/img404/3418/10x.png

If I run this code on it:

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from PIL import Image
 
i = Image.open('10x.bmp') # I save image as a bmp

for pixel in i.getdata():

    if pixel [2] > 0:

        print pixel

I get 88 results, which is what I'm after but I now need their 'x' positions.
What would I be doing wrong with bvdet's code that it doesn't work for me?

bvdet

You are not using the code I suggested. In your case, you want the pixel positions that have "B" values greater than 0.

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 from PIL import Image
 
img = Image.open('10x.png')

output = []

for col in range(img.size[0]):

    for row in range(img.size[1]):

        pixel = img.getpixel((col,row))

        if pixel[2] > 0:

            output.append((col,row))
 
for pixel in output:

    print pixel

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 >>> len(output)

88

>>> img.getpixel((122,73))

(17, 0, 9)

>>>

Thekid

Ah....! Thank you :)

How to locate a pixels position?

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