Re: problem with imwrite and underlying __magic_write__

[David Grundberg]

Ian Journeaux skrev:
>  
> 
> I am trying to troubleshoot a problem with the imwrite.m function. Under
> Windows, if I read in an 8-bit image with imread.m and write it out with
> imwrite.m, the image saved by imwrite is not exactly the same as what was
> read in.
> 
>  
> 
> This can be demonstrated with code as simple as 
> 
>  
> 
> I = imread('pickoutcentralin 32bit.png');
> 
> imwrite(I,'pickoutcentralout 32bit.png');
> 
>  
> 
> then compare the histograms of the ingoing and outgoing images. Has anyone
> else experienced this problem? Is there a workaround?
> 
>  
> 
> imwrite.m pretty much passes through its parameters to __magic_write__ so
> the problem is likely in __magic_write__. Where is the sourcecode for
> __magic_write__?  I would like to take a stab at troubleshooting if a
> solution doesn't already exist.
> 

The builtin is defined in

src/DLD-FUNCTIONS/__magick_read__.cc

Grundberg