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Image Representation

We discuss the representation of image in digital format.

There are two ways to broadly divide digital images:

  • Raster images: These are pixel-based images, where each pixel has a specific intensity or color value.
  • Vector images: These are mathematical representations of images, where each element is defined by mathematical equations.

Raster images can be broadly classified into:

  • Grayscale images: These images have only one channel, representing the intensity of each pixel.
  • Color images: These images have multiple channels, typically representing the red, green, and blue (RGB) components of each pixel.

There are two common memory layouts for representing multi-channel raster images:

  • Structure of Arrays (SoA) / planar representation: Each channel is stored as a separate 2D array. For example, an RGB image has one array for red, one for green, and one for blue.
  • Array of Structures (AoS) / interleaved representation: Each pixel stores all its channel values together. For example, each pixel may store (R, G, B).