How to change RGB stream to Grayscale?

[xuzhiyuan29]

I am a freshman of realsense sdk 2.0 and I am learning it from the example capture. I need to change the output from RGB to Grayscale . I think it might have something to do with the class colorizer, but I don't know how to set about. Can you please give me some advice?

Below are the codes of the example:

#include <librealsense2/rs.hpp> // Include RealSense Cross Platform API
#include "example.hpp" // Include short list of convenience functions for rendering

// Capture Example demonstrates how to
// capture depth and color video streams and render them to the screen
int main(int argc, char * argv[]) try
{
// Create a simple OpenGL window for rendering:
window app(1280, 720, "RealSense Capture Example");
// Declare two textures on the GPU, one for color and one for depth
texture depth_image, color_image;

// Declare depth colorizer for pretty visualization of depth data
rs2::colorizer color_map;

// Declare RealSense pipeline, encapsulating the actual device and sensors
rs2::pipeline pipe;
// Start streaming with default recommended configuration
pipe.start();

while(app) // Application still alive?
{
    rs2::frameset data = pipe.wait_for_frames(); // Wait for next set of frames from the camera

   // rs2::frame depth = color_map(data.get_depth_frame()); // Find and colorize the depth data
	rs2::frame depth = color_map(data.get_depth_frame());
    rs2::frame color = data.get_color_frame();            // Find the color data

    // Render depth on to the first half of the screen and color on to the second
    depth_image.render(depth, { 0,               0, app.width() / 2, app.height() });
    color_image.render(color, { app.width() / 2, 0, app.width() / 2, app.height() });
}

return EXIT_SUCCESS;

}
catch (const rs2::error & e)
{
std::cerr << "RealSense error calling " << e.get_failed_function() << "(" << e.get_failed_args() << "):\n " << e.what() << std::endl;
return EXIT_FAILURE;
}
catch (const std::exception& e)
{
std::cerr << e.what() << std::endl;
return EXIT_FAILURE;
}

[dorodnic]

Hi @xzyxzy29
Could you clarify if you are referring to the output of the depth or the color sensor?

[xuzhiyuan29]

Well, the output of the depth.

[xuzhiyuan29]

@dorodnic

[RealSense-Customer-Engineering]

[Realsense Customer Engineering Team Comment]
The RGB sensor also support Y16 format, this is a grayscale, as below screenshot you can see that.
You can set the image format to Y16 as follows.
// Declare RealSense pipeline, encapsulating the actual device and sensors
rs2::pipeline pipe;
rs2::config c;
c.enable_stream(RS2_STREAM_COLOR, 640, 480, RS2_FORMAT_Y16, 30);
pipe.start(c);
Of course, you also need to modify the rendering method in the sample you mentioned to display the grayscale image.

[RealSense-Customer-Engineering]

[Realsense Customer Engineering Team Comment]
@xzyxzy29 Do you still have any further question about this ticket?