DLPC350: Gamma correction for lightcrafter DLP4500

Antony Orth

Part Number: DLPC350
Other Parts Discussed in Thread: DLP4500

I recently bought a DLP4500 lightcrafter based unit from EKB technologies. I'm having some trouble in my application that requires a linear response to input 8-bit pixel value. When run through HDMI, I'm getting artifacts that look like they may be a result of a nonlinear response (unwanted gamma corrected). If this DLP4500 w/ DLPC350 system is run with HDMI input, is the default setting set to apply some gamma correction? If so, how to I present this? Also, what is the default gamma curve?

over 2 years ago

0 Antony Orth over 2 years ago

Prodigy 10 points

prevent, not present!

0 Alexander Chan over 2 years ago in reply to Antony Orth

TI__Genius 9540 points

Hi,

Welcome to the E2E forums with your questions.

In the dlp4500evm user guide it seems like the DLPC350 is performing gamma correction.

Looking at the DLPC350 data sheet it seems to only mention degamma in the block diagram.

Please give us some more time to look into this issue. We should have and support different degamma curves so may need to create or support new firmware.

Thanks,

Alex Chan

0 Alexander Chan over 2 years ago in reply to Alexander Chan

TI__Genius 9540 points

Hi,

After looking into this issue, one proposed option would be to use pattern sequence mode for your application, not video mode through HDMI. However in this case, the input should be 912x1140 – Diamond pixel format.

From the user guide which I have attached, pattern sequence mode will bypass any video processing where the degamma normally occurs.

https://www.ti.com/lit/pdf/dlpu011

Thanks,

Alex Chan

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DLPC350: Gamma correction for lightcrafter DLP4500