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Noise reduction on Epson projectors = Motion Blur
Apr 16, 2016, 6:44p - Technology

Occasionally, I discover that something that should be known online is not. And occasionally when this happens, I figure out the solution. This happened yesterday, so I wanted to record it on the net.

Internet, this one is for you.

About a month ago, I bought a refurbished LCD projector, an Epson Powerlite Home Cinema 2030, to setup a home theater in the living room of our new home. But when I plugged in my old Sony Blu-ray player, the video was fullof motion blur or lag. When something moved on the screen, there was a trailing ghost image, making it hard to see anything clearly. This blu-ray player had worked fine in Boston on the DLP projector we used there, so I thought it might be incompatible with my new LCD projector.

To rule out the projector as the cause, I plugged in my laptop with its blu-ray player, and the picture looked sharp and crisp without any motion lag. So, I thought, it must be a problem with our blu-ray player. I googled to see if others had had this issue, and all I could dig up was that LCD projectors and TVs are known to have some motion blur, apparently because the LCD can't refresh fast enough. But no one was describing my strange issue where my laptop played beautifully and the dedicated blu-ray player did not, and no one seemed to be returning their LCD projector because of it.

So I went to Best Buy, bought a new blu-ray player, came home, tested it. Fail - still see motion blur. Back to Best Buy, on to player #2. After buying, testing, and returning 3 blu-ray players over 2 weeks or so, Best Buy flagged my account and now warned me that I may not be able to return anything for awhile. Oh well, time to use Becca's credit card. Same problem with the 4th player, a Samsung. So now I'm thinking, it must be the projector + blu-ray combination.

I rarely call tech support, because the people on the other line often know less about their product than I do. But I had run out of options. I called Epson tech support, and they told me to set the "Image Processing" setting from Fine to Fast. I had tried this before and not seen any improvement, so I reluctantly made the change. Luckily, this time I changed the setting right after turning on the projector and blu-ray player. Turns out, if you change Image Processing while a Blu-ray is playing, the projector ignores the change, even though it says the setting has been changed. The Blu-ray player has to recently have been turned on and on its home screen, and only then does making the change actually take effect! I knew something different had happened because the projector menu got enlarged. And then when I went to play the blu-ray, no more motion blur! It finally worked!

But I was a bit puzzled and concerned that having image processing set to Fast would compromise the picture quality. Fiddling a bit more, I found that the Image Processing setting actually wasn't the culprit. It was the stupid "Noise reduction" setting. By default, Fine image processing sets noise reduction to 3, its max value. The standard algorithm for reducing noise in images is to blur everything just a bit, smoothening out the colors. But it turns out that this projector isn't actually powerful enough to do this at 30 fps without compromising the picture quality by introducing motion blur. Lowering noise reduction down to 1 or Off removed the motion blur altogether! Noise reduction changes can be made while a blu-ray is played and you see an immediate effect.

Success at last, after a month of buying and returning blu-ray players! Epson, your noise reduction sucks big time. One last trip to Best Buy, to trade this Samsung blu-ray player for a Sony, because I like the lower contrast image of the Sony more.

Anyhow, hopefully this little tip will help a Google searcher save some time and frustration in the future.

Read comments (2) - Comment

Siddharth Bhatla - Apr 28, 2016, 4:56a
Maybe it is the higher bit-rate of Blu-ray player that's the actual culprit for overloading the frame-buffers/RAM of the projector's image processing unit....

Turns out that noise reduction is required more in amateur videos whose bit-rate is naturally set lower ( upto 20 Mbps for Phone Cameras ) by camera designers to save memory for longer videos..

Conversely, Professionally created footage, has higher bit-rates ( 50-70 Mbps for High End DSLRs ) and Blu-ray can support upto 40 Mbps, and Imperfections like Noise is dealt with in Production Stage so we don't much of it in Broadcast-ed / Distributed Media... So Designers at EPSON may have taken that assumption while including those Noise Reduction settings in the projector's menu.

Glad to Hear from you !

Siddharth Bhatla

Anonymous - Jan 26, 2019, 9:33p
Thank you !

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