In packed pixel or chunky framebuffer organization, the bits defining each pixel are clustered and stored consecutively.[1] For example, if there are 16 bits per pixel, each pixel is represented in two consecutive (contiguous) 8-bit bytes in the framebuffer. If there are 4 bits per pixel, each framebuffer byte defines two pixels, one in each nibble. The latter example is as opposed to storing a single 4-bit pixel in a byte, leaving 4 bits of the byte unused. If a pixel has more than one channel, the channels are interleaved when using packed pixel organization.

Packed pixel displays were common on early microcomputer system that shared a single main memory for both the central processing unit (CPU) and display driver. In such systems, memory was normally accessed a byte at a time, so by packing the pixels, the display system could read out several pixels worth of data in a single read operation.

Packed pixel is one of two major ways to organize graphics data in memory, the other being planar organization, where each pixel is made of individual bits stored in their own plane. For a 4-bit color value, memory would be organized as four screen-sized planes of one bit each and a single pixel's value built up by selecting the appropriate bit from each plane. Planar organization has the advantage that the data can be accessed in parallel, and is used when memory bandwidth is an issue.

See also

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References

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  1. ^ "Pixel and Planar Image Formats". software.intel.com. 2018-11-07. Retrieved 2019-03-28.


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YCbCr

g1, b1, .... YCbCr packed pixel formats are often referred to as "Y′UV". Such files can be encoded in 12, 16 or 24 bits per pixel. Depending on subsampling

Pixel format

by the sensor, and the method by which pixel information is stored (packed pixel and planar pixel). The pixel format for the sensor is typically user-configurable

BMP file format

the pixel array to a multiple of 4 bytes. For "packed DIBs" loaded in memory, the optional color profile data should immediately follow the pixel array

Planar (computer graphics)

method of arranging pixel data into several bitplanes of RAM. Each bit in a bitplane is related to one pixel on the screen. Unlike packed, high color, or

Bitmap

example, converts 24-bit images to 32 bits per pixel. The bits representing the bitmap pixels may be packed or unpacked (spaced out to byte or word boundaries)

Pixel 8

The Pixel 8 and Pixel 8 Pro are a pair of Android-based smartphones designed, developed, and marketed by Google as part of the Google Pixel product line

Glossary of computer graphics

bit per pixel in a contiguous 2D array; Several such parallel arrays combine to produce the a higher-bit-depth image. Opposite of packed-pixel format.

Active-pixel sensor

An active-pixel sensor (APS) is an image sensor where each pixel sensor unit cell has a photodetector (typically a pinned photodiode) and one or more active