Preface

In the use of fpga When displaying pictures , Need to use ROM IP Nuclear to carry out the picture mif File storage , This article will use matlab Generate image's mif file

One 、 Generation steps

1. Process the image size

Use the drawing software provided by the computer , Change the pixel size of the picture , Change to the desired size

2. stay matlab New folder

Put picture files in the folder ,.bmp Format picture

3. Input code generation mif file

clear               % Clean up the command line window 
clc                 % Clean up the work area 

%  Use imread Function to read pictures , And transform it into a three-dimensional matrix 
image_array = imread('picture.bmp');

%  Use size Function to calculate the size of the three dimensions of the image matrix 
%  The first dimension is the height of the picture , The second dimension is the width of the picture , The third dimension is the picture dimension 
[height,width,z]=size(image_array);   % 100*100*3
red   = image_array(:,:,1); %  Extract the red component , The data type is uint8
green = image_array(:,:,2); %  Extract the green component , The data type is uint8
blue  = image_array(:,:,3); %  Extract the blue component , The data type is uint8

%  Use reshape The function reconstitutes each component into a one-dimensional matrix 
% To avoid spillage , take uint8 Type of data is expanded to uint32 type 
r = uint32(reshape(red'   , 1 ,height*width));
g = uint32(reshape(green' , 1 ,height*width));
b = uint32(reshape(blue'  , 1 ,height*width));

%  Initialization to write .mif In the document RGB Color matrix 
rgb=zeros(1,height*width);

%  The imported picture is 24bit True color pictures , Each pixel occupies 24bit,RGB888
%  take RGB888 Convert to RGB565
%  The red component shifts to the right 3 Bit take out high 5 position , Move left 11 as ROM in RGB The number of data 15bit To the first 11bit
%  The green component shifts to the right 2 Bit take out high 6 position , Move left 5 as ROM in RGB The number of data 10bit To the first 5bit
%  The blue component shifts to the right 3 Bit take out high 5 position , Move left 0 as ROM in RGB The number of data 4bit To the first 0bit
for i = 1:height*width
    rgb(i) = bitshift(bitshift(r(i),-3),11)+ bitshift(bitshift(g(i),-2),5)+ bitshift(bitshift(b(i),-3),0);
end

fid = fopen( 'image.mif', 'w+' );

% .mif File string printing 
fprintf( fid, 'WIDTH=16;\n');
fprintf( fid, 'DEPTH=%d;\n\n',height*width);

fprintf( fid, 'ADDRESS_RADIX=UNS;\n');
fprintf( fid, 'DATA_RADIX=HEX;\n\n');

fprintf(fid,'%s\n\t','CONTENT');
fprintf(fid,'%s\n','BEGIN');

%  Write picture data 
for i = 1:height*width
    fprintf(fid,'\t\t%d\t:%x\t;\n',i-1,rgb(i));
end

%  Print end string 
fprintf(fid,'\tEND;');

fclose( fid ); %  Close file pointer 

Pay attention to the third line of code , Write the file name of the image file , You need to fill in the file name of the saved image

4. File generation

Write the code and press enter to generate it in the folder mif The file