Color vs Monochrome Cameras

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Alonso
Posts: 109
Joined: 05 Dec 2016, 05:55
Location: USA

Color vs Monochrome Cameras

Post by Alonso »

Hello everyone,

I was curious if anyone had experience using color machine vision cameras vs monochrome for 3d scanning?

I know typically monochrome is recommended but what exactly are the downsides to using color cameras?
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OBNRacerMan
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Joined: 12 Aug 2019, 09:46
Location: Obninsk, Russia

Re: Color vs Monochrome Cameras

Post by OBNRacerMan »

Alonso wrote: 20 Jun 2021, 21:18 I know typically monochrome is recommended but what exactly are the downsides to using color cameras?
The main disadvantage of a color camera is the presence of a Bayer filter, which splits the light flux into RGB components that go to the corresponding sub-pixels of each pixel of the matrix.
There is no such filter in a monochrome camera, so each sub-pixel gets a complete "light picture". Since there are 4 sub-pixels (RGGB) in a pixel, in theory, the sensitivity of a monochrome camera should be higher.

Also, in my opinion, monochrome cameras "perceive" color objects better than a color camera with subsequent conversion in the program "to monochrome".

P.S. I didn’t have "identical" cameras (so that one camera had a color and monochrome version) .. so all my feelings from comparing 5.1MP color cameras like YW500U3 and 6.3MP (Mindvision and Daheng)
Soft: RangeVision DIY, Calibration panel/Rotary tables - RangeVision, Prj: LG PF1500G, Cam: Daheng Mercury MER2-630-60U3M-L (USB3.0, monochrome) x2, Obj: ZLKC FM12036MP5 (F2.8/5Mp/12-36mm) x2. And a handheld scanner Creality Ferret
Alonso
Posts: 109
Joined: 05 Dec 2016, 05:55
Location: USA

Re: Color vs Monochrome Cameras

Post by Alonso »

Thanks for the explanation OBN!

This link was helpful as well.
https://www.baslerweb.com/en/sales-supp ... ature-set/

It looks like Basler has gone an extra step to improve color camera performance...
Alonso
Posts: 109
Joined: 05 Dec 2016, 05:55
Location: USA

Re: Color vs Monochrome Cameras

Post by Alonso »

So I got a good deal on some used Basler color cameras to see for myself. Here are the results :D

The results are "OK" but it is evident that FS3D isn't using the PGI processing available with Basler cameras.
I was able to verify this after installing PylonViewer. Even after setting Demosaicing Mode to Basler PGI, FS3D sets it back to simple every time :(
Due to this, Noise Reduction and Sharpness Enhancement parameters can't be used either.
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FlexScan3D_FTa69VVmaY.png
Alonso
Posts: 109
Joined: 05 Dec 2016, 05:55
Location: USA

Re: Color vs Monochrome Cameras

Post by Alonso »

This single scan also has a bit of a rainbow effect. According to the Basler documentation, PGI should help eliminate this as well.
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FlexScan3D_nasQywrwLh.png
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