Am 04.08.2014 20:51, schrieb Christian Baun:

> "When rendering a subset of columns (+sc/+ec) and/or rows (+sr/+er), POV-Ray
> generates a full width image and fills the not rendered columns with black
> pixels. This should not be a problem for any image reading program no matter
> what file format is used. Earlier versions of POV-Ray had problems when a subset
> of rows (+sr/+er) was rendered. The full height information was written into the
> image file header but it only wrote image data for those lines that were
> actually rendered. This made output files that were incompatible with various
> image processing tools. In version 3.7 this is no longer the case."
>
> Is there any way to get the old behavior back without doing a downgrade?
> Is there any "hidden" command line option?

No.

> The new behavior makes distributed image generation very complicated.

It should still be easy enough to do with any batch image manipulation 
tool: Just blend the partial images using your choice of "add", 
"screen", "exclusion" or "lighten" operation, and Bob's your uncle.

For instance, using the ImageMagick tools this should be as simple as:

     composite -compose lighten "foo.ppm" "bar.ppm" "foobar.ppm"

There are various advantages to this; not only does it save you from the 
hassle of trimming away the header of the second image; it also works 
with any image file format, allows for more flexibility in partitioning 
of the render job, allows for overlap of the rendered regions (if you 
choose the "lighten" operation), and also allows for file format 
conversion as you go.

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