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# Pixel Overflow

[Laboratory]

When performing pixel arithmetic, the result of the operation may not fit within the pixel data type. This experiment illustrates this problem by adding a constant to all image pixels.

a)Original image unsigned byte; b)Result of adding 80 to its pixels
a) | b)

The problem with the above image is that the pixel data type is unsigned byte. With this data type we can only represent values from 0 to 255. Adding 80 to 255 gives (255+80) - 256 = 79 (wraparound), which is a dark pixel value.

To solve this wraparound effect, we can convert the pixel data type to unsigned short (16 bits) and then perform the addition.

Result with data type short

- Lab: Pixel Overflow