### 1.3.7 POV-Ray for Unix Tips

#### 1.3.7.1 Automated execution

POV-Ray for Unix is well suited for automated execution, for example, for rendering diagrams displaying statistical data on a regular basis or similar things.

POV-Ray can also write its image output directly to stdout. Therefore the image data can be piped in another program for further processing. To do this the special output filename '-' needs to be specified. For instance:

    povray -iscene.pov +fp -o- | cjpeg > scene.jpg

will pass the image data to the `cjpeg` utility which writes the image in the JPEG format.

The text output of POV-Ray is always written to stderr, it can be redirected to a file with (using a Bourne-compatible shell):

    povray [Options] 2> log.txt

See also Directing Text Streams to Files.

For remote execution of POV-Ray, as for example in a rendering service on the web, make sure you read and comply with the POV-Ray Legal Document.

#### 1.3.7.2 Post-processing Images

For Unix systems, the PBM utilities (PBMPLUS, NetPBM) and ImageMagick are an excellent choice for post-processing utilities, especially if you only have a command-line interface to Unix.