OpenCV  4.0.1 Open Source Computer Vision
Graph API: Converting image from one color space to another

## Functions

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

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

GMat cv::gapi::BGR2LUV (const GMat &src)
Converts an image from BGR color space to LUV 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::LUV2BGR (const GMat &src)
Converts an image from LUV color space to BGR color space. More...

GMat cv::gapi::RGB2Gray (const GMat &src)
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

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

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

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::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...

## § BGR2Gray()

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

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.
See also
BGR2LUV

## § BGR2LUV()

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

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.
See also
RGB2Lab, RGB2LUV

## § BGR2YUV()

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

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.
See also
YUV2BGR

## § LUV2BGR()

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

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.
See also
BGR2LUV

## § RGB2Gray() [1/2]

 GMat cv::gapi::RGB2Gray ( const GMat & src )

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.
See also
RGB2YUV

## § RGB2Gray() [2/2]

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

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.
See also
RGB2YUV

## § RGB2Lab()

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

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.
See also
RGB2YUV, RGB2LUV

## § RGB2YUV()

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

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.
See also
YUV2RGB, RGB2Lab

## § YUV2BGR()

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

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.
See also
BGR2YUV

## § YUV2RGB()

 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.

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.
See also
RGB2Lab, RGB2YUV