基于FPGA的图像RGB转HLS实现,包含testbench和MATLAB辅助验证程序

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1.算法运行效果图预览

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将FPGA结果导入到MATLAB显示效果:

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2.算法运行软件版本

Vivado2019.2

 

matlab2022a

 

3.算法理论概述

        在数字图像处理中,RGB和HLS是两种常见的颜色空间。RGB基于红绿蓝三种基本颜色的叠加来定义其他颜色,而HLS则代表色调、亮度和饱和度,它更接近人类视觉对颜色的感知。将RGB图像转换为HLS图像的目的通常是为了更方便地进行某些类型的图像处理,比如色彩平衡和色彩分离。RGB颜色空间基于笛卡尔坐标系,其中R、G、B分别代表红、绿、蓝三种颜色的强度。HLS颜色空间则是基于圆柱坐标系,其中H代表色调(0-360度),L代表亮度(0-1),S代表饱和度(0-1)。

 

        转换的第一步是将RGB值归一化到[0,1]范围。然后,通过计算RGB颜色空间的最大值和最小值来得到亮度L。色调H由RGB中的最大值和最小值决定,并使用反正切函数来得到0-360度的角度。最后,饱和度S基于最大值和亮度L来计算。

 

具体的转换公式如下:

 

将RGB值归一化到[0,1]:

R' = R/255

G' = G/255

B' = B/255

 

3.1计算最大值和最小值

 

Max = max(R', G', B')

Min = min(R', G', B')

Diff = Max - Min

 

3.2计算亮度L

 

L = (Max + Min) / 2

 

 

3.3计算饱和度S

if L < 0.5:

S = Diff / (Max + Min)

else:

S = Diff / (2 - Max - Min)

 

3.4计算色调H

 

if Diff == 0:

H = 0

else:

if Max == R':

H = (60 * ((G' - B') / Diff) + 360) % 360

elif Max == G':

H = (60 * ((B' - R') / Diff) + 120) % 360

elif Max == B':

H = (60 * ((R' - G') / Diff) + 240) % 360

 

       这些公式可以将每一个像素从RGB颜色空间转换到HLS颜色空间。值得注意的是,这种转换通常是可逆的,也就是说,你也可以从HLS颜色空间转换回RGB颜色空间。在实现RGB到HLS的转换时,通常会先读取一幅RGB图像,然后将上述公式应用于图像中的每一个像素。

 

 

 

 

4.部分核心程序 ``timescale 1ns / 1ps

//

// Company:

// Engineer:

//

// Create Date: 2023/08/01 

// Design Name:

// Module Name: RGB2gray

// Project Name:

// Target Devices:

// Tool Versions:

// Description:

//

// Dependencies:

//

// Revision:

// Revision 0.01 - File Created

// Additional Comments:

//

//

 

module test_image;

 

reg i_clk;

reg i_rst;

reg [7:0] Rbuff [0:100000];

reg [7:0] Gbuff [0:100000];

reg [7:0] Bbuff [0:100000];

reg [7:0] i_Ir,i_Ig,i_Ib;

wire [7:0] o_H;

wire [7:0] o_L,o_S;

integer fids1,dat1,fids2,dat2,fids3,dat3,jj=0;

 

 

 

 

//D:\FPGA_Proj\FPGAtest\codepz

initial

begin

        fids1 = $fopen("D:\FPGA_Proj\FPGAtest\codepz\R.bmp","rb");

        dat1  = $fread(Rbuff,fids1);

        $fclose(fids1);

end

 

initial

begin

        fids2 = $fopen("D:\FPGA_Proj\FPGAtest\codepz\G.bmp","rb");

        dat2  = $fread(Gbuff,fids2);

        $fclose(fids2);

end

 

initial

begin

        fids3 = $fopen("D:\FPGA_Proj\FPGAtest\codepz\B.bmp","rb");

        dat3 = $fread(Bbuff,fids3);

        $fclose(fids3);

end

 

 

 

initial

begin

i_clk=1;

i_rst=1;

#1200;

i_rst=0;

end

 

always #5  i_clk=~i_clk;

 

always@(posedge i_clk)

begin

        i_Ir<=Rbuff[jj];

        i_Ig<=Gbuff[jj];

        i_Ib<=Bbuff[jj];

        jj<=jj+1;

end

 

 

 

main_RGB2HLS main_RGB2HLS_u(

.i_clk    (i_clk),

.i_rst    (i_rst),

.i_image_R      (i_Ir),

.i_image_G      (i_Ig),

.i_image_B      (i_Ib),

.o_H            (o_H),// Y

.o_L            (o_L),// Y

.o_S            (o_S)

);

 

 

integer fout1;

initial begin

 fout1 = $fopen("H.txt","w");

end

 

always @ (posedge i_clk)

 begin

    if(jj<=66616)

        $fwrite(fout1,"%d\n",o_H);

        else

        $fwrite(fout1,"%d\n",0);

end

 

integer fout2;

initial begin

 fout2 = $fopen("L.txt","w");

end

 

always @ (posedge i_clk)

 begin

    if(jj<=66616)

        $fwrite(fout2,"%d\n",o_L);

        else

        $fwrite(fout2,"%d\n",0);

end

 

 

integer fout3;

initial begin

 fout3 = $fopen("S.txt","w");

end

 

always @ (posedge i_clk)

 begin

    if(jj<=66616)

        $fwrite(fout3,"%d\n",o_S);

        else

        $fwrite(fout3,"%d\n",0);

end

endmodule`