OpenCV  4.5.1 Open Source Computer Vision
Graph API: Converting image from one color space to another

## Functions

GMat cv::gapi::BayerGR2RGB (const GMat &src_gr)
Converts an image from BayerGR color space to RGB. The function converts an input image from BayerGR color space to RGB. The conventional ranges for G, R, and B channel values are 0 to 255. More...

GMat cv::gapi::BGR2Gray (const GMat &src)
Converts an image from BGR color space to gray-scaled. More...

GMat cv::gapi::BGR2I420 (const GMat &src)
Converts an image from BGR color space to I420 color space. More...

GMat cv::gapi::BGR2LUV (const GMat &src)
Converts an image from BGR color space to LUV color space. More...

GMat cv::gapi::BGR2RGB (const GMat &src)
Converts an image from BGR color space to RGB color space. More...

GMat cv::gapi::BGR2YUV (const GMat &src)
Converts an image from BGR color space to YUV color space. More...

GMat cv::gapi::I4202BGR (const GMat &src)
Converts an image from I420 color space to BGR color space. More...

GMat cv::gapi::I4202RGB (const GMat &src)
Converts an image from I420 color space to BGR color space. More...

GMat cv::gapi::LUV2BGR (const GMat &src)
Converts an image from LUV color space to BGR color space. More...

GMat cv::gapi::NV12toBGR (const GMat &src_y, const GMat &src_uv)
Converts an image from NV12 (YUV420p) color space to BGR. The function converts an input image from NV12 color space to RGB. The conventional ranges for Y, U, and V channel values are 0 to 255. More...

GMatP cv::gapi::NV12toBGRp (const GMat &src_y, const GMat &src_uv)
Converts an image from NV12 (YUV420p) color space to BGR. The function converts an input image from NV12 color space to BGR. The conventional ranges for Y, U, and V channel values are 0 to 255. More...

GMat cv::gapi::NV12toGray (const GMat &src_y, const GMat &src_uv)
Converts an image from NV12 (YUV420p) color space to gray-scaled. The function converts an input image from NV12 color space to gray-scaled. The conventional ranges for Y, U, and V channel values are 0 to 255. More...

GMat cv::gapi::NV12toRGB (const GMat &src_y, const GMat &src_uv)
Converts an image from NV12 (YUV420p) color space to RGB. The function converts an input image from NV12 color space to RGB. The conventional ranges for Y, U, and V channel values are 0 to 255. More...

GMatP cv::gapi::NV12toRGBp (const GMat &src_y, const GMat &src_uv)
Converts an image from NV12 (YUV420p) color space to RGB. The function converts an input image from NV12 color space to RGB. The conventional ranges for Y, U, and V channel values are 0 to 255. More...

GMat cv::gapi::RGB2Gray (const GMat &src)
Converts an image from RGB color space to gray-scaled. More...

GMat cv::gapi::RGB2Gray (const GMat &src, float rY, float gY, float bY)

GMat cv::gapi::RGB2HSV (const GMat &src)
Converts an image from RGB color space to HSV. The function converts an input image from RGB color space to HSV. The conventional ranges for R, G, and B channel values are 0 to 255. More...

GMat cv::gapi::RGB2I420 (const GMat &src)
Converts an image from RGB color space to I420 color space. More...

GMat cv::gapi::RGB2Lab (const GMat &src)
Converts an image from RGB color space to Lab color space. More...

GMat cv::gapi::RGB2YUV (const GMat &src)
Converts an image from RGB color space to YUV color space. More...

GMat cv::gapi::RGB2YUV422 (const GMat &src)
Converts an image from RGB color space to YUV422. The function converts an input image from RGB color space to YUV422. The conventional ranges for R, G, and B channel values are 0 to 255. More...

GMat cv::gapi::YUV2BGR (const GMat &src)
Converts an image from YUV color space to BGR color space. More...

GMat cv::gapi::YUV2RGB (const GMat &src)
Converts an image from YUV color space to RGB. The function converts an input image from YUV color space to RGB. The conventional ranges for Y, U, and V channel values are 0 to 255. More...

## ◆ BayerGR2RGB()

 GMat cv::gapi::BayerGR2RGB ( const GMat & src_gr )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from BayerGR color space to RGB. The function converts an input image from BayerGR color space to RGB. The conventional ranges for G, R, and B channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.bayergr2rgb"
Parameters
 src_gr input image: 8-bit unsigned 1-channel image CV_8UC1.
YUV2BGR, NV12toRGB

## ◆ BGR2Gray()

 GMat cv::gapi::BGR2Gray ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from BGR color space to gray-scaled.

The conventional ranges for B, G, and R channel values are 0 to 255. Resulting gray color value computed as

$\texttt{dst} (I)= \texttt{0.114} * \texttt{src}(I).B + \texttt{0.587} * \texttt{src}(I).G + \texttt{0.299} * \texttt{src}(I).R$

Note
Function textual ID is "org.opencv.imgproc.colorconvert.bgr2gray"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC1.
BGR2LUV

## ◆ BGR2I420()

 GMat cv::gapi::BGR2I420 ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from BGR color space to I420 color space.

The function converts an input image from BGR color space to I420. The conventional ranges for R, G, and B channel values are 0 to 255.

Output image must be 8-bit unsigned 1-channel image. CV_8UC1. Width of I420 output image must be the same as width of input image. Height of I420 output image must be equal 3/2 from height of input image.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.bgr2i420"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.
I4202BGR

## ◆ BGR2LUV()

 GMat cv::gapi::BGR2LUV ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from BGR color space to LUV color space.

The function converts an input image from BGR color space to LUV. The conventional ranges for B, G, and R channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.bgr2luv"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.
RGB2Lab, RGB2LUV

## ◆ BGR2RGB()

 GMat cv::gapi::BGR2RGB ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from BGR color space to RGB color space.

The function converts an input image from BGR color space to RGB. The conventional ranges for B, G, and R channel values are 0 to 255.

Output image is 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.bgr2rgb"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.
RGB2BGR

## ◆ BGR2YUV()

 GMat cv::gapi::BGR2YUV ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from BGR color space to YUV color space.

The function converts an input image from BGR color space to YUV. The conventional ranges for B, G, and R channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.bgr2yuv"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.
YUV2BGR

## ◆ I4202BGR()

 GMat cv::gapi::I4202BGR ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from I420 color space to BGR color space.

The function converts an input image from I420 color space to BGR. The conventional ranges for B, G, and R channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image. CV_8UC3. Width of BGR output image must be the same as width of input image. Height of BGR output image must be equal 2/3 from height of input image.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.i4202bgr"
Parameters
 src input image: 8-bit unsigned 1-channel image CV_8UC1.
BGR2I420

## ◆ I4202RGB()

 GMat cv::gapi::I4202RGB ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from I420 color space to BGR color space.

The function converts an input image from I420 color space to BGR. The conventional ranges for B, G, and R channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image. CV_8UC3. Width of RGB output image must be the same as width of input image. Height of RGB output image must be equal 2/3 from height of input image.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.i4202rgb"
Parameters
 src input image: 8-bit unsigned 1-channel image CV_8UC1.
RGB2I420

## ◆ LUV2BGR()

 GMat cv::gapi::LUV2BGR ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from LUV color space to BGR color space.

The function converts an input image from LUV color space to BGR. The conventional ranges for B, G, and R channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.luv2bgr"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.
BGR2LUV

## ◆ NV12toBGR()

 GMat cv::gapi::NV12toBGR ( const GMat & src_y, const GMat & src_uv )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from NV12 (YUV420p) color space to BGR. The function converts an input image from NV12 color space to RGB. The conventional ranges for Y, U, and V channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.nv12tobgr"
Parameters
 src_y input image: 8-bit unsigned 1-channel image CV_8UC1. src_uv input image: 8-bit unsigned 2-channel image CV_8UC2.
YUV2BGR, NV12toRGB

## ◆ NV12toBGRp()

 GMatP cv::gapi::NV12toBGRp ( const GMat & src_y, const GMat & src_uv )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from NV12 (YUV420p) color space to BGR. The function converts an input image from NV12 color space to BGR. The conventional ranges for Y, U, and V channel values are 0 to 255.

Output image must be 8-bit unsigned planar 3-channel image CV_8UC1. Planar image memory layout is three planes laying in the memory contiguously, so the image height should be plane_height*plane_number, image type is CV_8UC1.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.nv12torgbp"
Parameters
 src_y input image: 8-bit unsigned 1-channel image CV_8UC1. src_uv input image: 8-bit unsigned 2-channel image CV_8UC2.
YUV2RGB, NV12toRGBp, NV12toBGR

## ◆ NV12toGray()

 GMat cv::gapi::NV12toGray ( const GMat & src_y, const GMat & src_uv )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from NV12 (YUV420p) color space to gray-scaled. The function converts an input image from NV12 color space to gray-scaled. The conventional ranges for Y, U, and V channel values are 0 to 255.

Output image must be 8-bit unsigned 1-channel image CV_8UC1.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.nv12togray"
Parameters
 src_y input image: 8-bit unsigned 1-channel image CV_8UC1. src_uv input image: 8-bit unsigned 2-channel image CV_8UC2.
YUV2RGB, NV12toBGR

## ◆ NV12toRGB()

 GMat cv::gapi::NV12toRGB ( const GMat & src_y, const GMat & src_uv )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from NV12 (YUV420p) color space to RGB. The function converts an input image from NV12 color space to RGB. The conventional ranges for Y, U, and V channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.nv12torgb"
Parameters
 src_y input image: 8-bit unsigned 1-channel image CV_8UC1. src_uv input image: 8-bit unsigned 2-channel image CV_8UC2.
YUV2RGB, NV12toBGR

## ◆ NV12toRGBp()

 GMatP cv::gapi::NV12toRGBp ( const GMat & src_y, const GMat & src_uv )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from NV12 (YUV420p) color space to RGB. The function converts an input image from NV12 color space to RGB. The conventional ranges for Y, U, and V channel values are 0 to 255.

Output image must be 8-bit unsigned planar 3-channel image CV_8UC1. Planar image memory layout is three planes laying in the memory contiguously, so the image height should be plane_height*plane_number, image type is CV_8UC1.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.nv12torgbp"
Parameters
 src_y input image: 8-bit unsigned 1-channel image CV_8UC1. src_uv input image: 8-bit unsigned 2-channel image CV_8UC2.
YUV2RGB, NV12toBGRp, NV12toRGB

## ◆ RGB2Gray() [1/2]

 GMat cv::gapi::RGB2Gray ( const GMat & src )
Python:
retval=cv.gapi.RGB2Gray(src)

#include <opencv2/gapi/imgproc.hpp>

Converts an image from RGB color space to gray-scaled.

The conventional ranges for R, G, and B channel values are 0 to 255. Resulting gray color value computed as

$\texttt{dst} (I)= \texttt{0.299} * \texttt{src}(I).R + \texttt{0.587} * \texttt{src}(I).G + \texttt{0.114} * \texttt{src}(I).B$

Note
Function textual ID is "org.opencv.imgproc.colorconvert.rgb2gray"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC1.
RGB2YUV

## ◆ RGB2Gray() [2/2]

 GMat cv::gapi::RGB2Gray ( const GMat & src, float rY, float gY, float bY )
Python:
retval=cv.gapi.RGB2Gray(src)

#include <opencv2/gapi/imgproc.hpp>

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Resulting gray color value computed as

$\texttt{dst} (I)= \texttt{rY} * \texttt{src}(I).R + \texttt{gY} * \texttt{src}(I).G + \texttt{bY} * \texttt{src}(I).B$

Note
Function textual ID is "org.opencv.imgproc.colorconvert.rgb2graycustom"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC1. rY float multiplier for R channel. gY float multiplier for G channel. bY float multiplier for B channel.
RGB2YUV

## ◆ RGB2HSV()

 GMat cv::gapi::RGB2HSV ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from RGB color space to HSV. The function converts an input image from RGB color space to HSV. The conventional ranges for R, G, and B channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.rgb2hsv"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.
YUV2BGR, NV12toRGB

## ◆ RGB2I420()

 GMat cv::gapi::RGB2I420 ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from RGB color space to I420 color space.

The function converts an input image from RGB color space to I420. The conventional ranges for R, G, and B channel values are 0 to 255.

Output image must be 8-bit unsigned 1-channel image. CV_8UC1. Width of I420 output image must be the same as width of input image. Height of I420 output image must be equal 3/2 from height of input image.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.rgb2i420"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.
I4202RGB

## ◆ RGB2Lab()

 GMat cv::gapi::RGB2Lab ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from RGB color space to Lab color space.

The function converts an input image from BGR color space to Lab. The conventional ranges for R, G, and B channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image CV_8UC1.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.rgb2lab"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC1.
RGB2YUV, RGB2LUV

## ◆ RGB2YUV()

 GMat cv::gapi::RGB2YUV ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from RGB color space to YUV color space.

The function converts an input image from RGB color space to YUV. The conventional ranges for R, G, and B channel values are 0 to 255.

In case of linear transformations, the range does not matter. But in case of a non-linear transformation, an input RGB image should be normalized to the proper value range to get the correct results, like here, at RGB $$\rightarrow$$ Y*u*v* transformation. Output image must be 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.rgb2yuv"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.
YUV2RGB, RGB2Lab

## ◆ RGB2YUV422()

 GMat cv::gapi::RGB2YUV422 ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from RGB color space to YUV422. The function converts an input image from RGB color space to YUV422. The conventional ranges for R, G, and B channel values are 0 to 255.

Output image must be 8-bit unsigned 2-channel image CV_8UC2.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.rgb2yuv422"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.
YUV2BGR, NV12toRGB

## ◆ YUV2BGR()

 GMat cv::gapi::YUV2BGR ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from YUV color space to BGR color space.

The function converts an input image from YUV color space to BGR. The conventional ranges for B, G, and R channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.yuv2bgr"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.
BGR2YUV

## ◆ YUV2RGB()

 GMat cv::gapi::YUV2RGB ( const GMat & src )

#include <opencv2/gapi/imgproc.hpp>

Converts an image from YUV color space to RGB. The function converts an input image from YUV color space to RGB. The conventional ranges for Y, U, and V channel values are 0 to 255.

Output image must be 8-bit unsigned 3-channel image CV_8UC3.

Note
Function textual ID is "org.opencv.imgproc.colorconvert.yuv2rgb"
Parameters
 src input image: 8-bit unsigned 3-channel image CV_8UC3.