Sobel简介及代码实现

一.Sobel简介

• 一句话可以概况为，分别求水平与竖直梯度，然后求平方和再开方（近似的话就直接求绝对值之和），最后与设定的阈值进行比较，大于的话就赋值为0，小于的话就赋值为255。

• x方向梯度dx的求法：3*3的图像矩阵与下面的矩阵在对应位置相乘然后相加

  

• y方向梯度dy的求法：同上

  

二.代码实现

这里采用近似计算G = |dx| + |dy|, 正负号分开计算，然后用大的数减去小的数

reg[10:0]  Sobel_px ,Sobel_nx;reg[10:0]  Sobel_py ,Sobel_ny;
wire[10:0]  Sobel_x;wire[10:0]  Sobel_y;
wire[7:0]  Sobel_data;
//x方向的梯度assign Sobel_x = (Sobel_px > Sobel_nx) ? (Sobel_px - Sobel_nx) : (Sobel_nx - Sobel_px);//y方向的梯度assign Sobel_y = (Sobel_py > Sobel_ny) ? (Sobel_py - Sobel_ny) : (Sobel_ny - Sobel_py);assignSobel_data=(Sobel_x+Sobel_y>'d135)?'d0:'d255;


always@(posedge clk_9M or negedge rst)begin  if(rst == 1'b0)    begin      Sobel_px <= 'd0;      Sobel_nx <= 'd0;    end  else if(cur_x >= 'd100 && cur_x <= 'd199 && cur_y >= 'd50)    begin      Sobel_nx <= data_line_11 + data_line_21 + data_line_21 + data_line_31;      Sobel_px <= data_line_13 + data_line_23 + data_line_23 + data_line_33;    end  else    begin    Sobel_nx <= 'd0;    Sobel_px <= 'd0;    endend

always@(posedge clk_9M or negedge rst)begin  if(rst == 1'b0)    begin      Sobel_py <= 'd0;      Sobel_ny <= 'd0;    end  else if(cur_x >= 'd100 && cur_x <= 'd199 && cur_y >= 'd50)    begin      Sobel_py <= data_line_11 + data_line_12 + data_line_12 + data_line_13;      Sobel_ny <= data_line_31 + data_line_32 + data_line_32+ data_line_33;    end  else    begin      Sobel_ny <=  'd0;      Sobel_py <=  'd0;    endend

审核编辑：汤梓红