FPGA Verilog实现基本的图像滤波处理仿真

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：
img = imread('E:\matlab\Images\2016-09-05-211710.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,'\r\n'); end
end
end
figure,imshow(img);
fclose(s);

2、EdgeSobel的Verilog源代码：
`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：tb_EdgeSobel.v
`timescale 1ns / 1ps

module tb_edgesobel;

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,"\r\n");
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:\matlab\Vivado\mem2image.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。