Bmp Comression to upload image to DLP Lightcrafter 6500 EVM

Hello Trevor,

sorry for my english, but I try to explain again.

I want (for testing purposes) transfer with a command line program one image. I used that https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/94/hidtest_5F00_with_5F00_response_5F00_bit.cpp sample. The transmission is very, very slow and takes about 30 seconds or more.

(and also I do not understand, how to convert the 0_Binary.bmp into 0_Binary.bin).

On the Evaluation GUI, the 0_Binary.bmp is transmitted very fast (because it is compressed). So I want to find out, how to convert the uncompressed bmp to compressed to speed up the transmission in my console program.

But I do not understnad the docs in Appendix C Pattern Image Compression. Is in the Evaluation Applicaton RLE or Enhanced RLE used?

Why is in the Example Number 0x1234 encoded as 0xB4, 0x24  (the first hex Byte 0x12 shift >> 7 to 0x24(?), ok, 0x34 &0x/f | 0x80 to 0xB4.

But when I see in the example:

82 01 789ABC, how is the result (513 times) created?

Hi f st,

I am not sure if you have solved this yet or not. I have similar questions regarding the programmer's guide and here's what I did.

I ignored what happened in the example (82 01 789ABC) and just followed the control bytes table. I think it is not the most optimum way but I simply prioritized "copy from previous line" over "repeating". And with my program written in Matlab (which is far from optimized and probably has some bugs), the 0_Binary.bmp can be compressed to 8 KB and takes 0.15s to transfer.

Here's the program:

clc;close all;clear

fileID = fopen('rgb.bmp'); 
A = fread(fileID);
fclose(fileID);

B = A(end-1920*1080*3+1:end); % Suppose rgb.bmp is 24-bit

w = 1920;
h = 1080;

Bcomp = [];
count = zeros(h,1);

% First Line
n = 1;
ptr = 1;
repeat = 1;
Bline = B((n-1)*w*3+1:n*w*3);
while ptr <= length(Bline)-3
    % Max n = 256*256/2-1 = 32767
    if repeat == 256*256/2
        rep1 = bitor(bitand(repeat-1,hex2dec('7f')),hex2dec('80'));
        rep2 = bitshift(repeat-1,-7);
        Bcomp = [Bcomp;rep1;rep2;rgb];
        count(n) = count(n) + repeat - 1;
        repeat = 1;
    end
    rgb = Bline(ptr:ptr+2);
    ptrn = ptr+3;
    rgbn = Bline(ptrn:ptrn+2);
    if isequal(rgb,rgbn)
        repeat = repeat + 1;
        ptr = ptrn;
        continue
    elseif repeat<128
        Bcomp = [Bcomp;repeat;rgb];
        count(n) = count(n) + repeat;
        repeat = 1;
        ptr = ptrn;
    else
        rep1 = bitor(bitand(repeat,hex2dec('7f')),hex2dec('80'));
        rep2 = bitshift(repeat,-7);
        Bcomp = [Bcomp;rep1;rep2;rgb];
        count(n) = count(n) + repeat;
        repeat = 1;
        ptr = ptrn;
    end
end
if repeat<128
    Bcomp = [Bcomp;repeat;rgbn];
else
    rep1 = bitor(bitand(repeat,hex2dec('7f')),hex2dec('80'));
    rep2 = bitshift(repeat,-7);
    Bcomp = [Bcomp;rep1;rep2;rgbn];
end
count(n) = count(n) + repeat;
Bcomp = [Bcomp;0;0];

% Second till End Lines
for n = 2:h
    Blinep = Bline;
    Bline = B((n-1)*w*3+1:n*w*3);
    
    Blp = reshape(Blinep,3,1920);
    Blc = reshape(Bline,3,1920);
    copyFlag = zeros(1920,1);
    for m = 1:1920
        copyFlag(m) = isequal(Blp(:,m),Blc(:,m));
    end
    
    idx = 1;
    copy = 0;
    repeat = 1;
    
    while idx <= 1920
        while copyFlag(idx)&&(idx<=1920)&&(copy<256*256/2-1)
            copy = copy + 1;
            idx = idx + 1;
            if idx == 1921
                break
            end
        end
        if copy>0&&copy<128
            Bcomp = [Bcomp;0;1;copy];
            count(n) = count(n) + copy;
        elseif copy>0
            cop1 = bitor(bitand(copy,hex2dec('7f')),hex2dec('80'));
            cop2 = bitshift(copy,-7);
            Bcomp = [Bcomp;0;1;cop1;cop2];
            count(n) = count(n) + copy;
        end
        copy = 0;
        if idx == 1921
            break
        end
        if copyFlag(idx)
            continue
        end
        
        while (~copyFlag(idx))&&(idx<=1920)
            if repeat == 256*256/2
                rep1 = bitor(bitand(repeat-1,hex2dec('7f')),hex2dec('80'));
                rep2 = bitshift(repeat-1,-7);
                Bcomp = [Bcomp;rep1;rep2;rgb];
                count(n) = count(n) + repeat - 1;
                repeat = 1;
            end
            ptr = (idx-1)*3+1;
            rgb = Bline(ptr:ptr+2);
            ptrn = ptr+3;
            rgbn = Bline(ptrn:ptrn+2);
            if isequal(rgb,rgbn)
                repeat = repeat + 1;
                idx = idx + 1;
                continue
            elseif repeat<128
                Bcomp = [Bcomp;repeat;rgb];
                count(n) = count(n) + repeat;
                repeat = 1;
                idx = idx + 1;
            else
                rep1 = bitor(bitand(repeat,hex2dec('7f')),hex2dec('80'));
                rep2 = bitshift(repeat,-7);
                Bcomp = [Bcomp;rep1;rep2;rgb];
                count(n) = count(n) + repeat;
                repeat = 1;
                idx = idx + 1;
            end
        end
        if isequal(rgb,rgbn)
            if repeat-1<128
                Bcomp = [Bcomp;repeat-1;rgbn];
                count(n) = count(n) + repeat - 1;
            else
                rep1 = bitor(bitand(repeat-1,hex2dec('7f')),hex2dec('80'));
                rep2 = bitshift(repeat-1,-7);
                Bcomp = [Bcomp;rep1;rep2;rgbn];
                count(n) = count(n) + repeat - 1;
            end
        end
        repeat = 1;
    end
    
    if n ~= h
        % End of Line
        Bcomp = [Bcomp;0;0];
    else
        % End of Image
        Bcomp = [Bcomp;0;1;0];
    end
 end

Hope it helps!

Regards,

Ding