Image Processing Toolbox

Image Arithmetic Truncation Rules

The results of integer arithmetic can easily overflow the data type allotted for storage. For example, the maximum value you can store in uint8 data is 255. Arithmetic operations can also result in fractional values, which cannot be represented using integer arrays.

The image arithmetic functions use these rules for integer arithmetic:

• Values that exceed the range of the integer type are truncated to that range
• Fractional values are rounded

For example, if the data type is uint8, results greater than 255 (including Inf) are set to 255. The following table lists some additional examples.

Result	Class	Truncated Value
300	uint8	255
-45	uint8	0
10.5	uint8	11

Summary of Image Arithmetic Functions

Adding Images