STEMMER IMAGING

Look-up tables (LUT)

Another widely used technique in image processing is 'Look-Up Tables'. LUTs allow image data to be passed through an array that maps an input pixel value to an output value.

Instead of performing mathematical operations on every pixel in the image, the grey value is mapped in the so-called look-up table in a fraction of the time it would take to process each pixel. This is the reason why gamma correction is usually executed using look-up tables.

This technique is easy to implement in hardware and is a very efficient way of improving processing speed. Typical functions that can be implemented using LUTs include: changing image contrast and brightness, or applying a threshold to produce a bi-level (binary) image.

 

Example: LUT being used for gamma correction

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Learn more about:

• Image arithmetic and flat-field correction
• Geometric correction and image de-warping
• Thresholding
• Filtering
• Morphological functions
• 2D calibration
• Colour space conversion