Glossary¶
- Channel
One of several data values persent in each pixel. Examples include red, green, blue, alpha, etc. The data in one channel of a pixel may be represented by a single number, whereas the pixel as a whole requires one number for each channel.
- Client
A client (as in “client application”) is a program or library that uses OpenImageIO or any of its constituent libraries.
- Data format
The representation used to store a piece of data. Examples include 8-bit unsigned integers, 32-bit floating-point numbers, etc.
- Image File Format
The specification and data layout of an image on disk. For example, TIFF, JPEG/JFIF, OpenEXR, etc.
- Image Format Plugin
A DSO/DLL that implements the ImageInput and ImageOutput classes for a particular image file format.
- Format Plugin
See image format plugin.
- Metadata
Data about data. As used in OpenImageIO, this means Information about an image, beyond describing the values of the pixels themselves. Examples include the name of the artist that created the image, the date that an image was scanned, the camera settings used when a photograph was taken, etc.
- Native data format
The data format used in the disk file representing an image. Note that with OpenImageIO, this may be different than the data format used by an application to store the image in the computer’s RAM.
- Pixel
One pixel element of an image, consisting of one number describing each channel of data at a particular location in an image.
- Plugin
See image format plugin.
- Scanline
A single horizontal row of pixels of an image. See also tile.
- Scanline Image
An image whose data layout on disk is organized by breaking the image up into horizontal scanlines, typically with the ability to read or write an entire scanline at once. See also tiled image.
- Tile
A rectangular region of pixels of an image. A rectangular tile is more spatially coherent than a scanline that stretches across the entire image — that is, a pixel’s neighbors are most likely in the same tile, whereas a pixel in a scanline image will typically have most of its immediate neighbors on different scanlines (requiring additional scanline reads in order to access them).
- Tiled Image
An image whose data layout on disk is organized by breaking the image up into rectangular regions of pixels called tiles. All the pixels in a tile can be read or written at once, and individual tiles may be read or written separately from other tiles.
- Volume Image
A 3-D set of pixels that has not only horizontal and vertical dimensions, but also a “depth” dimension.