Error Concealment | JPEG | MPEG-4 | Wavelet | YUV

Hello Friends,

I am developing an application where I have to do Jpeg 
decompression. But I don't have enough RAM in my micro controller to 
store the jpg image. Neither the controller has EMI to interface 
SRAM.

Can I decompress the jpg step wise. I meant MCU (Minimum Coded Unit) 
wise.
For example I will not store the full image and then decompress 
rather I will store one MCU then decode it; then free the RAM and 
will repeat the process. Will it work properly.

Are there any dependencies between MCUs?

Please respond.
Thanks & regards,
Rosarium

(You need to be a member of imagedsp -- send a blank email to imagedsp-subscribe@yahoogroups.com )

There will be dependencies between MCUs, unless theres a restart marker appearing after
each MCU.

But your method will still work, as long as you store the context of the jpeg decoder(DC
predictors, bitstream position etc) in between the MCU decodes. Decode one MCU .. Transfer
decompressed MCU to some other larger memory like SDRAM (using DMA perhaps). Decode next MCU..

Regards
Ranjith
----- Original Message ----
From: rosarium.pila <r...@yahoo.com>
To: i...@yahoogroups.com
Sent: Friday, 7 December, 2007 5:05:01 PM
Subject: [imagedsp] Jpg decompression with inadequate RAM

Hello Friends,

I am developing an application where I have to do Jpeg 
decompression. But I don't have enough RAM in my micro controller to 
store the jpg image. Neither the controller has EMI to interface 
SRAM.

Can I decompress the jpg step wise. I meant MCU (Minimum Coded Unit) 
wise.
For example I will not store the full image and then decompress 
rather I will store one MCU then decode it; then free the RAM and 
will repeat the process. Will it work properly.

Are there any dependencies between MCUs?

Please respond.

Thanks & regards,
Rosarium

(You need to be a member of imagedsp -- send a blank email to imagedsp-subscribe@yahoogroups.com )