> Grant,
>
> All we are trying to say is that -normalize may lose data. As you are
> on a rather old system. I would suggest, you simply try using
> -contract-stretch 0 rather than -normalize and see what happens.
>
> Each image is different. Thus it may need custom tuning. You may not
> be able to use one technique across the boards.
>
> You can try -contrast-stretch with various percentages until you find
> something you like. You may even need to try other techniques as
> there is no one best way to process every image. You can use -level
> as another approach to try, but again you may have to tune the values
> it uses to your image to get the best results.
>
> I know nothing about how to do this in perlmagick, but there is User
> Group for that on the discourse server at
> http://www.imagemagick.org/discourse-server/. You can inquire there.
>
> Good luck
>
> Fred
Thanks Fred. I don't want to fine-tune for each image, so which
technique do you think it most likely to work well for any image I run
through it? I can update imagemagick no problem. Will I fare better
with a newer version?
- Grant
>> > With regard to my suggestion for using -contrast-stretch, I would
>>> note that it also uses a histogram to stretch the image.
>>>
>>> The other way to do this is to feed the min and max image values to
>>> -level. Anthony Thyssen has recently greatly improved this function.
>>> So in unix with a shell, you could do (in IM 6.3.9-1 or higher)
>>>
>>> min=`identify -format "%[min]"`
>>> max=`identify -format "%[max]"`
>>> convert <inputimage> -level ${min},${max} <outputimage>
>>>
>>> That would be the most exact method for stretching the image so that
>>> it just exactly spans the range from 0 to QuantumRange, i.e. from
>>> full black to full white.
>>>
>>>
>>> See notes about -level (and +level) at
>>> http://www.imagemagick.org/Usage/color/#contrast
>>
>>Thanks for the help guys. Anthony points to Fred's work and Fred
>>points to Anthony's work. I'm a little confused on the best way to do
>>this. Is it the above? I'm using imagemagick-6.3.8.3-r1 with
>>perlmagick.
>>
>>- Grant
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