# immultiply

Multiply two images or multiply image by constant

## Description

example

Z = immultiply(X,Y) multiplies each element in array X by the corresponding element in array Y and returns the product in the corresponding element of the output array Z.

## Examples

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Read a grayscale image into the workspace, then convert the image to uint8.

I16 = uint16(I);

Multiply the image by itself. Note that immultiply converts the class of the image from uint8 to uint16 before performing the multiplication to avoid truncating the results.

J = immultiply(I16,I16);

Show the original image and the processed image.

imshow(I)

figure
imshow(J)

Read an image into the workspace.

Scale each value of the image by a constant factor of 0.5.

J = immultiply(I,0.5);

Display the original image and the processed image.

imshow(I)

figure
imshow(J)

## Input Arguments

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First array, specified as a numeric array or logical array of any dimension.

Second array to be multiplied with X, specified as a numeric scalar, numeric array, or logical array.

• If X is numeric, then the size and class of Y can have one of the following values:

• Y is the same size and class as X.

• Y is the same size as X and is logical.

• Y is a scalar of type double.

• If X is logical, then Y must have the same size as X. Y can be any class.

## Output Arguments

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Product, returned as a numeric array.

• If X is numeric, then Z has the same size and class as X.

• If X is logical, then Z has the same size and class as Y.

immultiply computes each element of Z individually in double-precision floating point. If X or Y is an integer array, then elements of Z exceeding the range of the integer type are truncated, and fractional values are rounded.

## Tips

• If X and Y are numeric arrays of the same size and class, then you can use the expression X.*Y instead of immultiply.

## Version History

Introduced before R2006a