demosaic

Convert Bayer pattern encoded image to truecolor image

Syntax

RGB = demosaic(I,sensorAlignment)

Description

RGB = demosaic(I,sensorAlignment) converts the Bayer pattern encoded image, I, to the truecolor image, RGB, using gradient-corrected linear interpolation. sensorAlignment specifies the Bayer pattern.

A Bayer filter mosaic, or color filter array, refers to the arrangement of color filters that let each sensor in a single-sensor digital camera record only red, green, or blue data. The patterns emphasize the number of green sensors to mimic the human eye's greater sensitivity to green light. The demosaic function uses interpolation to convert the two-dimensional Bayer-encoded image into the truecolor image.

Examples

Convert a Bayer Pattern Encoded Image To an RGB Image

Convert a Bayer pattern encoded image that was photographed by a camera with a sensor alignment of 'bggr' .

I = imread('mandi.tif');
J = demosaic(I,'bggr');
imshow(I);

figure, imshow(J);

Input Arguments

I — Bayer-pattern encoded image

M-by-N array of intensity values

Bayer-pattern encoded image, specified as an M-by-N array of intensity values. I must have at least 5 rows and 5 columns.

Data Types: uint8 | uint16 | uint32

sensorAlignment — Bayer pattern

'gbrg' | 'grbg' | 'bggr' | 'rggb'

Bayer pattern, specified as one of the values in the following table. Each value represents the order of the red, green, and blue sensors by describing the four pixels in the upper-left corner of the image (left-to-right, top-to-bottom).

Pattern	2–by-2 Sensor Alignment
'gbrg'
'grbg'
'bggr'
'rggb'

Data Types: char | string

Output Arguments

RGB — RGB image

M-by-N-by-3 numeric array

RGB image, returned as an M-by-N-by-3 numeric array the same class as I.

References

[1] Malvar, H.S., L. He, and R. Cutler, High quality linear interpolation for demosaicing of Bayer-patterned color images. ICASPP, Volume 34, Issue 11, pp. 2274-2282, May 2004.

Extended Capabilities

C/C++ Code Generation

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

Usage notes and limitations:

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

• sensorAlignment must be a compile-time constant.

GPU Code Generation

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

Usage notes and limitations:

• sensorAlignment must be a compile-time constant.

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

Version History

Introduced in R2007b

R2022b: Support for thread-based environments

demosaic now supports thread-based environments.