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Color correcting the camera feed


(Andrew Edwards) #1

Hey,
The video feed (Adv Electronics package with RPi and a fathom X) is REALLY green. Is there a way to color correct the feed or adjust the gamma?


(Rusty) #2

Andrew,

That’s interesting! Never seen that before. Can you send a screenshot? Sounds like you might have a defective camera.

-Rusty


(Andrew Edwards) #3

Hey Rusty,
I’m currently operating in a really remote area but as soon as I get
bandwidth I’ll upload a screen grab of the onboard vs attached GoPro. The
onboard is Hulk level green.


(Rusty) #4

Andrew - alright, that’s definitely not normal. There are ways to adjust the Raspberry Pi camera colors but I’m not sure how they would have gotten so messed up in the first place.


(William Gallagher) #5

Their is a filter to correct the green, can’t recall the color, put over the lens. But Sounds like you might be in a area of very high concentration of photosynthesis.


(Andrew Edwards) #6

So after testing with a couple of cheap FoPros (Fake GoPros) it does appear to be entirely environmental. All cameras show a major color tinge. The GoPro we use externally both color corrects very very well and provides a SIGNIFICANTLY further viewing distance. Is there a way to use a GoPro (hero 4, and 5 available) as the main camera? A way to interface it to the rPi? I’m not sure how well it’s analog feed will do with 300m of tether. I’m happy to. It an additional interface board if need be.


(Rusty) #7

Andrew - Wow, that’s really interesting. Can you share any shots of the area? There’s probably other areas that would experience the same issues and I’d really like to find a way to correct for that.

You can actually use a GoPro as the video feed if you use a HDMI to CSI converter like this one from AUVIDEA. We’ve haven’t done that ourselves but we’ve heard a few reports that it works well.

-Rusty


(k.deboer) #8

Hi Rusty,

You are correct. Other parts have green water too. The water is green in the cold waters of both the Atlantic, and Pacific off the costs of Canada. Here is a screen shot from the East Coast:

It’d be nice to have auto white balance in the camera. Maybe something like that might help.

-Ken


(Kaos) #9

I get similar green color in NZ waters but I find it is in shallow water no deeper than 10m. Makes potentially good video almost unusable. Life in the oceans,I suppose. Oh well


(undersearobotics.com) #10

Your best option for color correcting underwater video is either through the camera’s settings or by post processing the video (such as demonstrated in this video).

I recommend you avoid using a filter. Filters reduce the amount of light to the camera’s sensor, and in underwater video this is a major disadvantage.


(Ion Hernandez) #11

uau it´s really spectacular what you can do with the post precessing video. Thanks Paul


(Andrew Edwards) #12

Hey Rusty,
Sorry for the delayed response, I was in a remote area without stable internet. I’m trying to get a B101 HDMI Bridge so we can run the GoPro as the main camera. That would be an ideal solution.

See below for images captured with RPi cam vs the attached GoPro. As you can see, the onboard is VERY green. It makes it much more difficult to identify targets from any sort of range. For reference, we were operating in Lake Ontario on the Canadian side.


(undersearobotics.com) #13

I’ve noticed a distinct green tint added when using the advanced electronics (Raspberry Pi camera) versus the standard electronics (NTSC camera).


(Lauren Hayden) #14


We have been experiencing a green center as well. This picture is from a depth of about 3 meters in the Saco River in Maine, the water was actually brownish. This is our second Raspberry Pi camera.


(Andrew Edwards) #15

We’ve just received the new HD USB cam. I’ll let you guys know how we find it. I’ve also got an HDMI bridge on order so I should eventually be able to provide a comparison between the GoPro as a main camera and the new USB cam. I’m hopeful the new USB cam provides a suitable solution.


(Rusty) #16

@Kraken - Great! Let us know how it goes. Also see here about the cable during installation: New Low-Light HD USB Camera- Short cable


#17

I just changed from Raspberry camera to the new low light USB camera. It seems to be a lot better in low light, less distorted and sharper. The color saturation on the USB camera does look a little low. How do I adjust this on Windows?

Raspberry on the left and USB on the right, low light on top and max ROV light on the bottom


(Julian Hancock) #18

English Channel, Torbay. the green alway has more penetration of sea water where as the reds are lost in the first few centimetres, green can penetrate down to about 1000m.


(Jacob) #19

There is no way to do this that I am aware of at the moment. See also How to adjust compression on new HD cam? and USB camera to ROS.


#20

But possible on MacOS?