imcomplement

Complement image

Syntax

J = imcomplement(I)

Description

J = imcomplement(I) calculates the complement of the image I and returns the result in J.

In the complement of a binary image, zeros become ones and ones become zeros. Black and white are reversed.

In the complement of a grayscale or color image, each pixel value is subtracted from the maximum pixel value supported by the class (or 1.0 for double-precision images). The difference is used as the pixel value in the output image. In the output image, dark areas become lighter and light areas become darker. For color images, reds become cyan, greens become magenta, blues become yellow, and vice versa.

Examples

Create the Complement of a uint8 Array

X = uint8([ 255 10 75; 44 225 100]);
X2 = imcomplement(X)

X2 = 2×3 uint8 matrix

     0   245   180
   211    30   155

Reverse Black and White in a Binary Image

bw = imread('text.png');
bw2 = imcomplement(bw);
imshowpair(bw,bw2,'montage')

Create the Complement of an Intensity Image

I = imread('cameraman.tif');
J = imcomplement(I);
imshowpair(I,J,'montage')

Create the Complement of a Color Image

Read a color image into the workspace.

rgb = imread('yellowlily.jpg');
imshow(rgb)

Display the complement of the image.

c = imcomplement(rgb);
imshow(c)

Each color channel of the resulting image is the complement of the corresponding color channel in the original image. Regions that were dark, such as dirt, become light. In the original image, the leaves appear green, and petals appear yellow because of a mixture of red and green signals. In the complement image, the leaves appear purple because the red and blue signals are larger than the green signal. The flower petals appear blue because the blue signal is larger than the red and green channels.

Input Arguments

I — Input image

RGB image | grayscale image | binary image

Input image, specified as an RGB, grayscale, or binary image.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | logical

Output Arguments

J — Image complement

RGB image | grayscale image | binary image

Image complement, specified as an RGB, grayscale, or binary image. J has the same size and data type as the input image, I.

Tips

• If I is a grayscale or RGB image of class double, then you can use the expression 1-I instead of this function.

• If I is a binary image, then you can use the expression ~I instead of this function.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• imcomplement supports the generation of C and C++ code (requires MATLAB^® Coder™). For more information, see Code Generation for Image Processing.

• imcomplement does not support int64 and uint64 data types.

GPU Code Generation

Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Usage notes and limitations:

• imcomplement does not support int64 and uint64 data types.

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

This function fully supports GPU arrays. For more information, see Image Processing on a GPU.

Version History

Introduced before R2006a