Display for small JPEG pictures

Hi all, I am Lorenzo, from Italy. This is the first time that I write in the international forum: for me writing in english is a little problem, I hope that you would understand my message :) I readed a lot about arduino and LCDs, but I didn't find a dispaly suitable for my little project, so I decided to ask to the forum.

I have an arduino duemilanove and I'm going to buy a microSD breakout board. I need to store some JPEG pictures in the SD card and display them in the LCD. I found some LCDs that can display bitmap pictures, but no one that can read directly JPEG pictures. I know that arduino isn't fast enough to decompress an image from JPEG to BMP, so I need an external conversion shield, or better an external module with the converter and the display. Do you know if there is a shield suitable for my purpose?

Bye, Lorenzo!

PS: I don't necessarily need a LCD, a shield for VGA or RCA output and an external monitor would also be good.

Hi Lorenzo,

Welcome in Arduino world.

Actually, your concerns are a bit on the wrong side : it is not impossible for an Arduino to decode JPEG, it's just slow. But sending the image from a Duemilanove to the LCD will also be slow. And generating TV signal is even worse, it's only realistic for very low resolution black/white image !

I personally have a MEGA with ITDB02, and it contains a SD shield. with this configuration I could certainly display small JPEGs. How fast (or better, how slow) I don't know. There are a lot of alternatives for you : either you go to 3"2 16-bit LCD (ITDB02) or to serial interfaces (supposed to be faster, I'm not sure).

But in any case, you will have to implement a JPEG to bitmap conversion routine. You could also use a 80MHz 32-bit Arduino clone (eg. Maple) to get your decoding go faster. If this isn't fast enough, then you have to go to Linux SBCs with graphical chipsets. Much more expensive of course (200EUR++).

Thank you for the reply! I searched a lot, are these the screen and the adapter that you suggested? http://iteadstudio.com/store/index.php?main_page=product_info&cPath=57_58&products_id=54 http://iteadstudio.com/store/index.php?main_page=product_info&cPath=18&products_id=149

They seem very good! I readed the informations about the library, it seems that the screen would accept only array of bitmap data (is it the same of bitmap pictures?).

Now I'm trying to find out a script for arduino or Maple for jpeg to bmp conversion :)

Actually, the program to translate is on the same site as the libraries of Henning, see http://www.henningkarlsen.com/electronics/t_imageconverter565.php