---
name: "teem-overrgb"
section: "1"
platform: "linux"
package: "teem-apps"
version: "1.12.0~20160122-6"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/teem-overrgb"
---

# teem-overrgb(1)

Composites an RGBA nrrd over a background color.

## NAME

teem-overrgb - Composites an RGBA nrrd over a background color.

## SYNOPSIS

**teem-overrgb** *-i \<nin\>* \[*-c \<contrast\>*\] \[*-cfp \<fixed point\>*\] *\\fR*

## DESCRIPTION

*./teem-overrgb: Composites an RGBA nrrd over a background color (or image),* *after doing gamma correction, then quantizes to an 8-bit image. Actually, the* *input nrrd can have more than 4 values per pixel, but only the first four are* *used. If the RGBA nrrd is floating point, the values are taken at face value;* *if it is fixed point, the values interpreted as having been quantized (so that* *8-bit RGBA images will act as you expect). When compositing with a background* *image, the given background image does not have to be the same size as the* *input image; it will be resampled (with linear interpolation) to fit.*

-

  *\[-g \<gamma\>\] \[-b \<background\>\] \[-bi \<nbg\>\]* **-o** \<filename\>

**-i** \<nin\> = input nrrd to composite (nrrd)

- **-c** \<contrast\> = contrast to apply to RGB values, before gamma. "0.0"

  means no change, "1.0" means thresholding, "-1.0" means a complete washout. (double); default: "0.0"

**-cfp** \<fixed point\> = component level that doesn't change with contrast

-

  (double); default: "0.5"

- **-g** \<gamma\> = gamma to apply to image data, after contrast (double);

  default: "1.0"

- **-b** \<background\> = background color to composite against; white is 1 1 1,

  not 255 255 255. (3 doubles); default: "0 0 0"

- **-bi** \<nbg\> = 8-bit RGB background image to composite against (nrrd);

  default: ""

**-o** \<filename\> = file to write output PPM image to (string)

## SEE ALSO

The full documentation for **teem-overrgb** is maintained as a Texinfo manual.  If the **info** and **teem-overrgb** programs are properly installed at your site, the command

-

  **info teem-overrgb**

should give you access to the complete manual.