ppmwheel

Generate a color wheel of type Ppmcirc

$ ppmwheel [diameter] > [path/to/output.ppm]

$ ppmwheel [[-huev|-huevalue]] [diameter] > [path/to/output.ppm]

$ ppmwheel [[-hues|-huesaturation]] [diameter] > [path/to/output.ppm]

ppmwheel [-window widthxheight] [-sleep milliseconds] [-verbose] [-gamma value] [-default] [-install] [-name string]

-window widthxheight
    Specifies the width and height of the window in pixels. Defaults to the size of the first image.

-sleep milliseconds
    Sets the delay between frames in milliseconds. This controls the speed of the animation. The default is a platform-dependent default value.

-verbose
    Enables verbose output, providing information about the images being processed.

-gamma value
    Adjusts the gamma correction for the image display. A value of 1.0 means no correction.

-default
    Uses default visual (rather than trying to find a better one). If it doesn't work at all, then try this.

-install
    The window will be installed in the color map of the root window. This allows other programs to see the colors in the window. Without this option, the window will be in its own private color map.

-name string
    Sets the name of the window.

The ppmwheel command reads a sequence of PPM (Portable Pixmap) images from standard input and displays them in a window, smoothly rotating through the sequence. It's primarily used for creating simple animations or viewing image sequences. The command utilizes X11 for displaying the images.
ppmwheel is designed for quick and easy animation display, where each PPM image represents a frame in the animation. You can control the speed and size of the displayed animation using command-line options. It is part of the Netpbm suite of image manipulation tools, focusing on simple animation display.
It requires an X server to be running and configured correctly, since it relies on Xlib for image display. Without a running X server, ppmwheel will not function properly.

ppmwheel requires an X server to be running. It may not handle large images efficiently. The animation quality is limited by the speed of the X server and the system's resources.

ppmwheel expects a sequence of PPM images piped to its standard input. Each image should be a valid PPM file as defined by the Netpbm format.

ppmwheel loads each image in memory, there is no option for saving files or other actions of this nature. If you are trying to load many large files this can have a huge impact. Consider limiting the size of the images, and how many you use.

ppmwheel is part of the Netpbm suite, a collection of command-line tools for manipulating graphics images. Netpbm has been around since the early 1990s. The design goal of ppmwheel seems to be a simple way to display image sequences without the overhead of a full-fledged media player.

ppm(5), xwd(1), xv(1)