[Image-SIG] Re: PIL image processing

[Ajay Abhyankar]

Fredrik Lundh wrote:

>Ajay Abhyankar wrote:
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>>I have used lookup table for controlling the threshold of an image using the point(table) method. 
>>To set the threshold of an image, I create a list of 256 values. All values till threshold (in 
>>range 0-255) are turned to 0 and the rest above threshold value are turned to 255. This list is 
>>supplied to the point method as lookup table. When applied to the image it works fine.
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>>Similarly, if I want to manipulate Brightness/Contrast of an image using lookup table for an 
>>image, how can I get the lookup table for an image with existing values (so as to manipulate them) 
>>instead of creating a new lookup table.
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>images don't have lookup tables; the point method maps the pixel values
>through the table you provided, and returns a new image.
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>to create a linear lookup table, use "lut = range(256)"
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Hi,

Thanks for the reply.
I was able to change the brightness/contrast  using the point method.
out = im.point(lambda i: i * factor).

Regards,
Ajay