Implementing hardware Image compression on spatan 3 FPGA

hi,
i am going to do a electronic project which need image compressions.
i like to know your opinions on following questions as a newbie for FPGA.

the input to the FPGA are the RAW DATA from cmos camera like ov7620.

I need archive at least 20fps compression rate.(20 images must compressed in 1 second).
(This is not a video stream ,just still pictures )

the input raw data would be about 900k. i need a compression of 100k(900k-->100k)



1.What is best (or easy) to implement PNG or jpeg image compression .
(or any other compression methods!!!!!)

2.what is the advantage of having soft core (like microblaze of xilinx) for using a image compression

thanks
dilan

I have never really worked on compression. However, I would like to comment on your second question.

I don't think that a microprocessor (let alone a softcore MP implemented on top of CLBs) would be adequate for such a heavy and real-time dataprocessing task. You will have to design the processing mechanism in hardware (FPGA). Also, I would recommend you to make a rough guess of the quantity of data (in bytes) that you intend to feed into the chip in just one second. Then, calculate the datarate required (just divide the total databytes by the size of your intended databus)....You will need atleast this fast a clock (actually a faster clock internally, b/c you must do some intensive processing to get the size down to 900k to 100k - if that is even possible for every picture!). Check with the Spartan 3 datasheet, if this much clock rate is even supported (i doubt it)!!