VHDL jpeg image processing

Guest
Hi, I am a Master of UNIS and currently mapping c++ onto VHDL for image
processing. I confused with jpeg format into VHDL that how to extract
jpeg and how can I test it. Is it I put entities (rst, clk, data_in,
datai(64 downto 0), data_out, datao(64 downto 0) and I do 3 blocks for
IDCT, Dequantities, and Huff scanning and are they enough, hope anyone
can help.
Many thanks,
KY
 
You may try to look the opencores.org for jpeg core. I think there are
two of them. Xilinx has lots of appnotes about huffman, quantizer and
other stuff. Google for it.

The number of blocks you will need will depend on how you organize your
code. This is a design pratice, each designer has its own or follow
some convention. For example: your Huff has a small fifo inside, wich
is another block (or entity).

You do not seem a HDL experienced, so, I suggest some basics reading
too, on both the language and Digital design. You won´t regret doing
this.

Regards,

Ricardo

eem3kc@gmail.com escreveu:

Hi, I am a Master of UNIS and currently mapping c++ onto VHDL for image
processing. I confused with jpeg format into VHDL that how to extract
jpeg and how can I test it. Is it I put entities (rst, clk, data_in,
datai(64 downto 0), data_out, datao(64 downto 0) and I do 3 blocks for
IDCT, Dequantities, and Huff scanning and are they enough, hope anyone
can help.
Many thanks,
KY
Click to expand...
 
Ricardo 寫道：

You may try to look the opencores.org for jpeg core. I think there are
two of them. Xilinx has lots of appnotes about huffman, quantizer and
other stuff. Google for it.

The number of blocks you will need will depend on how you organize your
code. This is a design pratice, each designer has its own or follow
some convention. For example: your Huff has a small fifo inside, wich
is another block (or entity).

You do not seem a HDL experienced, so, I suggest some basics reading
too, on both the language and Digital design. You won´t regret doing
this.

Regards,

Ricardo

Thanks for your reply. Yes certainly I will not regret to do that. I
Click to expand...
have provided c++ code from my supervisor and there are several format
I can choose for mapping, bitmap png, ppg etc. And now I have to do is
to read too. So is that any book about image processing using VHDL??

But jpeg is essentially common, and I want to target on. Anyway, saw my
supervisor today and she asked me to look at read file functions and
take lines I need to process only and try. See if this works also.

Best regards,
KY
 
Thanks for your reply. Yes certainly I will not regret to do that. I
have provided c++ code from my supervisor and there are several format
I can choose for mapping, bitmap png, ppg etc. And now I have to do is
to read too. So is that any book about image processing using VHDL??
Click to expand...
Google is your friend.

But jpeg is essentially common, and I want to target on.Anyway, saw my
Click to expand...
try opencores, xilinx. Many of your blocks are there.

supervisor today and she asked me to look at read file functions and
Click to expand...
saerch for textio library.

take lines I need to process only and try. See if this works also.

Best regards,
KY
Click to expand...
 
I can do up to this point where to load images into modelsim for a
testbench. But I don't why the information load in a _ then it randomly
skipped a few lines. I think it is some sort of readline problem or
define input as : text. Anyone have this experience before???



My code is :-

library ieee;
use ieee.std_logic_1164.all;
use std.textio.all;
use ieee.numeric_std.all;

entity Loadimg is
port(
out_data_1 : out integer
);end Loadimg;

architecture fileio of loadimg is
file in_img_1 : text;

signal ch : character;
signal int : integer;

begin

img1: process is
variable ILine : Line;
variable ch : character;

begin
file_open(in_img_1, "imagename", read_mode)


while not endfile(in_img_1) loop
readline(in_img_1, ILine_1);
read(ILine_1, ch_1);
-- converts character stored in char to
-- integer (ASCII)
int_1 <= character'pos (ch_1);

out_data_1 <= int_1;

wait for 5 ns;

end loop;
file_close(in_img_1);

end process img1;
end architecture fileio;



For example .bmp format header should be BM†J.............ASCIIs.

It reads out B for the 1st character, convert into integer is 99, then
next should be M, but it straightly goes to colour data already 255
let's say.

I confused if I am using the right method to load a image into a
testbench.
 
I can do up to this point where to load images into modelsim for a
testbench. But I don't why the information load in a _ then it randomly

skipped a few lines. I think it is some sort of readline problem or
define input as : text. Anyone have this experience before???


My code is :-

library ieee;
use ieee.std_logic_1164.all;
use std.textio.all;
use ieee.numeric_std.all;

entity Loadimg is
port(
o ut_data_1 : out integer
);end Loadimg;

architecture fileio of Loadimg is
file in_img_1 : text;

signal ch : character;
signal int : integer;

begin
img1: process is
variable ILine : Line;
variable ch : character;

begin
file_open(in_img_1, "imagename", read_mode)
while not endfile(in_img_1) loop
readline(in_img_1, ILine);
read(ILine, ch);
-- converts character stored in char to
-- integer (ASCII)
int_1 <= character'pos (ch_1);
out_data_1 <= int_1;

wait for 5 ns;
end loop;
file_close(in_img_1);
end process img1;
end architecture fileio;



For example .bmp format header should be BM†J.............ASCIIs.
It reads out B for the 1st character, convert into integer is 99, then
next should be M, but it straightly goes to colour data already 255
let's say.
I confused if I am using the right method to load a image into a
testbench.
 
eem3kc@gmail.com wrote:

My code is :-

library ieee;
use ieee.std_logic_1164.all;
use std.textio.all;

For example .bmp format header should be BM†J.............ASCIIs.
It reads out B for the 1st character, convert into integer is 99, then
next should be M, but it straightly goes to colour data already 255
Click to expand...
textio only works with text.
Here's a binary file example:

http://home.comcast.net/~mike_treseler/char_file.vhd

-- Mike Treseler
 
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