FPGA设计中 Verilog HDL实现基本的图像滤波处理仿真

大侠好，欢迎来到FPGA技术江湖，江湖偌大，相见即是缘分。大侠可以关注FPGA技术江湖，在“闯荡江湖”、"行侠仗义"栏里获取其他感兴趣的资源，或者一起煮酒言欢。“煮酒言欢”进入IC技术圈，这里有近100个IC技术公众号。

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,'rn');   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,"rn");              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。