[Radiance-general] Image from text

[Greg Ward]

Hi Dave,

You need to read the pvalue man page a little more closely.  You can  
feed it an ASCII file with no header by employing the -h option  
together with -H to say there is no resolution string, but then you  
need to use -y YRES +x XRES options to specify the image resolution  
and scanline ordering.

Best,
-Greg

> From: dbs176 at gmail.com
> Date: January 30, 2009 7:49:39 AM PST
>
> Ah, thanks, pvalue does the trick.
>
> Two things of note though which I don't think are documented: It  
> looks like pvalue needs the ASCII input to have a Radiance header -  
> at least "#?RADIANCE" on the first line followed by a blank line.  
> In the command "pvalue -h image.hdr | pvalue -r > image2.hdr" the  
> second pvalue will not know what to do with the output from the  
> first pvalue.
>
> Also, the -d switch on pvalue works on the reverse operation as  
> well. If you do something like "pvalue -d image.hdr | pvalue -r >  
> image2.hdr", the second pvalue will use the header to determine the  
> dimensions but ignore the red and green columns (assuming they were  
> supposed to be x and y), so you'll get only the blue channel in  
> image2.hdr. However, "pvalue -d image.hdr | pvalue -r -d >  
> image2.hdr" will reproduce the original image. This behavior is  
> noted in the Bugs section but not in the description for the -d  
> option.
>
> --Dave