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SystemC Code Generation for Image Format Conversion from RGB to YUV

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This example shows how to generate SystemC™ code from a MATLAB® design that converts the image format from RGB to YUV.

MATLAB Design and Test Bench

Set up the Rgb2yuv model for this example.

mlhdlc_demo_setup('Rgb2yuv');
design_name = 'mlhdlc_rgb2yuv';
testbench_name = 'mlhdlc_rgb2yuv_tb';

no files copied to tempdir...

Review the Rgb2yuv design.

open(design_name)

function [x_out, y_out, y_data_out, u_data_out, v_data_out] = ...
                        mlhdlc_rgb2yuv(x_in, y_in, r_in, g_in, b_in)
%#codegen

%   Copyright 2011-2019 The MathWorks, Inc.

persistent RGB_Reg YUV_Reg
persistent x1 x2 y1 y2

if isempty(RGB_Reg)
    RGB_Reg = zeros(3,1);
    YUV_Reg = zeros(3,1);
    x1 = 0; x2 = 0; y1 = 0; y2 = 0;
end

D = [.299  .587  .144; -.147 -.289  .436; .615 -.515 -.1];
C = [0; 128; 128];

RGB = [r_in; g_in; b_in];

YUV_1 = D*RGB_Reg;
YUV_2 = YUV_1 + C;
RGB_Reg = RGB;

y_data_out = round(YUV_Reg(1));
u_data_out = round(YUV_Reg(2));
v_data_out = round(YUV_Reg(3));
YUV_Reg = YUV_2;

x_out = x2; x2 = x1; x1 = x_in;
y_out = y2; y2 = y1; y1 = y_in;

Review the Rgb2yuv test bench:

open(testbench_name);

FRAMES = 1;
WIDTH = 752;
HEIGHT = 480;
HBLANK = 10;%748;
VBLANK = 10;%120;

%   Copyright 2011-2019 The MathWorks, Inc.

vidData = double(imread('mlhdlc_img_yuv.tif'));

for f = 1:FRAMES
    vidOut = zeros(HEIGHT, WIDTH, 3);
    
    for y = 0:HEIGHT+VBLANK-1
        for x = 0:WIDTH+HBLANK-1
            if y >= 0 && y < HEIGHT && x >= 0 && x < WIDTH
                b = vidData(y+1,x+1,1);
                g = vidData(y+1,x+1,2);
                r = vidData(y+1,x+1,3);
            else
                b = 0; g = 0; r = 0;
            end           

            [xOut, yOut, yData, uData, vData] = ...
                mlhdlc_rgb2yuv(x, y, r, g, b);

            if yOut >= 0 && yOut < HEIGHT && xOut >= 0 && xOut < WIDTH
                vidOut(yOut+1,xOut+1,:) = [yData vData uData];
            end     
        end  
    end
    
    figure(1);
    subplot(1,2,1); 
    imshow(uint8(vidData));
    subplot(1,2,2); 
    imshow(ycbcr2rgb(uint8(vidOut)));
    drawnow;                
end

Test the MATLAB Algorithm

To avoid run-time errors, simulate the design with the test bench.

mlhdlc_rgb2yuv_tb

Create HDL Coder™ Project

To generate SystemC code from a MATLAB design:

1. Create a HDL Coder project:

coder -hdlcoder -new mlhdlc_rgb_prj

2. Add the file mlhdlc_rgb2yuv.m to the project as the MATLAB Function and mlhdlc_rgb2yuv_tb.m as the MATLAB Test Bench.

3. Click Autodefine types to use the recommended types for the inputs and outputs of the MATLAB function mlhdlc_rgb2yuv.

For more information, see Get Started with MATLAB to SystemC Workflow Using the Command Line Interface or Get Started with MATLAB to SystemC Workflow Using HDL Coder App.

Run Fixed-Point Conversion and SystemC Code Generation

To generate SystemC code from the MATLAB design:

1. At the MATLAB command line, set up the path for SystemC code generation by using the function hdlsetuphlstoolpath.

2. Start the Workflow Advisor by clicking the Workflow Advisor button.

3. In the HDL Workflow Advisor, select Code Generation Workflow as MATLAB to SystemC.

4. In the Select Code Generation Target step, from the Synthesis tool list, select Cadence Stratus.

5. Right-click the SystemC Code Generation task and select Run to selected task to run all the steps from the beginning through the SystemC code generation.

Examine the generated SystemC code by clicking the hyperlinks in the SystemC Code Generation task log window.

See Also