Fusion an Display with FPGA

[Altera_Forum]

hello, 

 I am trying to display a fusion of 2 cameras on PC Screen. I can display a image of each camera on screen. a Fusion is a simply Addition of two Pixel Grayvalue.  that problem is my Screen cannot show correctly the fusion image.  could someone give me some idea to resolve that?  thank u!

[Altera_Forum]

Depends on how you add the signals. If the cameras aren't operating sync locked, both images must be stored in a frame buffer before.

[Altera_Forum]

You need to average the inputs, not simply add them. Simply adding will cause a lot of saturation.

[Altera_Forum]

--- Quote Start ---  Depends on how you add the signals. If the cameras aren't operating sync locked, both images must be stored in a frame buffer before.  --- Quote End ---     thank you for this answer, now i am trying to realize a Framebuffer, i have a RAM with 1,152000 bit, for the a picture with the resolution 480 X 640 and 16 bit Color.   It is possible to realize a framebuffer?   I have readed somewhere that for VGA 480 X 640 X 16 i need 150 KB framebuffer........

[Altera_Forum]

For a frame buffer you will need external ram.

[Altera_Forum]

--- Quote Start ---  For a frame buffer you will need external ram.  --- Quote End ---   can you explain me why?

[Altera_Forum]

I tell a lie 

 It will depend on what device you are using. Older devices wont have enough. But even with newer ones, with all the losses due to innefficient memory implementation you wont have much memory left after you've put your frame buffer in.  What device are you using?

[Altera_Forum]

for reference: 

 1 M9k can store 512 x 16 bit data words. Therefore, with a basic and easy addressing scheme at 640 pixels per line and 480 line you need  2x M9k per line 480 lines  = 960 x M9k.  The largest Arria 2 device has 950 largest Cyclone 4 has 720 Stratix 4 has about ~1000 to 1200 M9Ks but also has larger M144ks  So a simple addressing scheme wont do. Even if you made the addressing more efficient, you're going to lose >50% of your internal memories to a frame buffer.  Lesson - any large data dumps are usually best done off chip.

[Altera_Forum]

--- Quote Start ---  I tell a lie   It will depend on what device you are using. Older devices wont have enough. But even with newer ones, with all the losses due to innefficient memory implementation you wont have much memory left after you've put your frame buffer in.   What device are you using?  --- Quote End ---     Thank u for ur answer iam using a Cyclone 2

[Altera_Forum]

--- Quote Start ---  Thank u for ur answer iam using a Cyclone 2  --- Quote End ---    Then you have no chance of using internal RAM for a frame buffer. You have to use external ram.