基于Verilog HDL的FPGA图像滤波处理仿真实现

今天给大侠带来FPGA设计中用Verilog HDL实现基本的图像滤波处理仿真，话不多说，上货。   1、用matlab代码，准备好把图片转化成Vivado Simulator识别的格式，即每行一个数据：

  代码：

 

img = imread('E:matlabImages2016-09-05-211710.jpg');
  if size(img,3)==3
     img = rgb2gray(img);
  end
  height = size(img, 1);
  width = size(img, 2);
  s = fopen('image2mem.txt','wb'); %opens the output file
  cnt = 0;
  for r=1:height
    for c=1:width
      cnt = cnt + 1;
      grey=img(r,c);
      greyb = dec2bin(grey,8);
      Outbyte =greyb(1:8);


      if (Outbyte(1:4) == '0000')fprintf(s,'0%X',bin2dec(Outbyte));
      else fprintf(s,'%X',bin2dec(Outbyte));   end
      if (mod(cnt,1) == 0)fprintf(s,'
');   end
    end
  end
  figure,imshow(img);
  fclose(s);

    2、EdgeSobel的Verilog源代码：

 

 

代码：

 

`timescale 1ns/1ps




module EdgeSobel(
     input clk,
     input [7:0] inData,
     input [11:0]x,
     input [11:0]y,
     output [7:0] outData
  );    




  parameter pixel_depth=8;
  parameter frame_width=640;
  parameter block_width=3;
  parameter block_height=3;




  parameter shiftRegSize=pixel_depth*((block_height-1)*frame_width+block_width);




  reg[shiftRegSize-1:0] shiftReg;
  wire [block_width*block_height*pixel_depth-1:0] Window;  




  initial begin shiftReg=10264'b0;end
  always@(posedge clk)if((x<640)&&(y<480))shiftReg<={shiftReg,inData};




  genvar i,j;
  generate
  for(i = 0; i < block_height; i = i + 1) begin : array
    for(j = 0; j < block_width; j = j + 1) 
    begin : vector
      assign Window[pixel_depth*(i * block_width + j)+:pixel_depth] =shiftReg[pixel_depth*(i*frame_width+j)+:pixel_depth];
    end
  end
  endgenerate




  wire [7:0] average;
  assign average = 
     (Window[7:0]+Window[15:8]+Window[23:16]+
    //Window[31:24]+Window[39:32]+Window[47:40]+
    Window[31:24]+Window[39:32]+Window[47:40]+
    Window[55:48]+Window[63:56]+Window[71:64])/9 ;




  wire signed [pixel_depth+1:0] Gx;
  wire signed [pixel_depth+1:0] Gy;
  wire [pixel_depth+1:0] Gxabs;
  wire [pixel_depth+1:0] Gyabs;
  wire [pixel_depth+1:0] G;




  assign Gx =   shiftReg[pixel_depth*(0*frame_width+2)+:pixel_depth]
        +2*shiftReg[pixel_depth*(1*frame_width+2)+:pixel_depth]
        +  shiftReg[pixel_depth*(2*frame_width+2)+:pixel_depth]
        -  shiftReg[pixel_depth*(0*frame_width+0)+:pixel_depth]
        -2*shiftReg[pixel_depth*(1*frame_width+0)+:pixel_depth]
        -  shiftReg[pixel_depth*(2*frame_width+0)+:pixel_depth];




  assign Gy =   shiftReg[pixel_depth*(2*frame_width+0)+:pixel_depth]
        +2*shiftReg[pixel_depth*(2*frame_width+1)+:pixel_depth]
        +  shiftReg[pixel_depth*(2*frame_width+2)+:pixel_depth]
        -  shiftReg[pixel_depth*(0*frame_width+0)+:pixel_depth]
        -2*shiftReg[pixel_depth*(0*frame_width+1)+:pixel_depth]
        -  shiftReg[pixel_depth*(0*frame_width+2)+:pixel_depth];   


  assign Gxabs = (Gx>0)?Gx-Gx);
  assign Gyabs = (Gy>0)?Gy-Gy);
  assign G = Gxabs+Gyabs;


  //assign outData = average;    //平滑
  assign outData = G[9:2];     //边缘检测

endmodule

3、仿真文件：EdgeSobel_tb.v

代码：

`timescale 1ns / 1ps

module edgesobel_tb;


  reg clk;
  reg [7:0]  inData;
  reg [19:0] cnt;
  reg [9:0] row;
  wire [7:0] outData;
  reg [7:0] image [307199:0];
  integer file_id;
  reg [4:0] frame_cnt;


  initial
  begin
    $readmemh("E:/matlab/Vivado/image2mem.txt", image);
    file_id = $fopen("E:/matlab/Vivado/mem2image.txt","w");
    clk = 0;
    cnt = 0;
    row = 0;
    frame_cnt = 0;
  end




  EdgeSobel u_2
      (
      .clk(clk),
      .x(1),
      .y(1),
      .inData(inData),
      .outData(outData)
      );




  always #1 clk = ~clk;




  always@(posedge clk)
  begin
    if(cnt == 307200)    
      begin
        cnt = 0;
        row = 0;
        frame_cnt = frame_cnt + 1;
      end    
    else 
      inData = image[cnt];
      cnt = cnt+1;
      if(frame_cnt==1)
        begin
          $fwrite(file_id, "%d ", outData);
          if(((cnt % 640)==0) &&(cnt>0)) 
            begin 
              $fwrite(file_id,"
");
              row = row + 1;
            end;
        end
  end

endmodule

4、把输出的txt文件转化成图片Matlab程序：

A=importdata('E:matlabVivadomem2image.txt');


A=A./255;


imshow(A);

注意这里的A是double类型的，直接进行imshow会全白，要转化到0-1：A=A./255，或者把double类型转化为整形。

审核编辑：黄飞