Result of cvtColor not displaying correctly for Lepoard Imaging USB 3.0 camera

asked 2015-07-23 13:52:42 -0500

jnj11 gravatar image

updated 2015-07-24 10:47:12 -0500

Using the code below, I am getting images from a Leopard Imaging USB 3.0 camera. When I first tested the camera, the images were green. I looked on several forums and found that I needed to convert from Bayer images to BGR images. Now, I get what is in the attached image. Does anyone know what I can do to fix this?

cv::VideoCapture (cam1);

cv::Mat changed;
cv::Mat bayer16(data.rows, data.cols, CV_16UC1,,data.step);
cv::Mat bayer8 = bayer16.clone();
bayer8.convertTo(bayer8, CV_8UC1, 0.0625);

cv::cvtColor(bayer8, changed, CV_BayerGB2BGR);
imshow("", changed);
An image of what gets displayed image

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it is because of the channels, the interpretation of the bits... do you have also some gray part in your displayed image, or is it all?

thdrksdfthmn gravatar imagethdrksdfthmn ( 2015-07-24 04:37:41 -0500 )edit

Yes, there is some gray but, the colors look more washed out. I added a link to the image so that you can see what I mean Image

jnj11 gravatar imagejnj11 ( 2015-07-24 10:16:02 -0500 )edit

I suggest you to review the bayer16; data is a Mat with the right nb of channels, and you are forcing it to a CV_16UC1 ... Are you sure that it is OK? Transforming from CV_32FC1 to CV_16UC1 should be a problem... More, then you convert it to CV_8UC1 with a resize factor...

thdrksdfthmn gravatar imagethdrksdfthmn ( 2015-07-27 02:46:36 -0500 )edit

No, I am not sure that this is correct. I found an example where I need to convert from a Bayer image to an RGB or BGR image. With no processing, the images coming from the camera look like this. When I cut down all of that code and just use cv::cvtColor(bayer8, changed, CV_BayerGB2BGR);
I get an error that says: OpenCV Error: Asserion failed (scn == 1 && (dcn == 3 || dcn ==4))
I need to convert that image to BGR. Do you have any suggestions about how to do that?

jnj11 gravatar imagejnj11 ( 2015-07-27 08:18:54 -0500 )edit

Verify the channels of received image: std::cout << data.channels() << std::endl; (or in debug) what is the number of channels data has?

thdrksdfthmn gravatar imagethdrksdfthmn ( 2015-07-27 09:21:06 -0500 )edit

Data has 3 channels

jnj11 gravatar imagejnj11 ( 2015-07-27 09:41:30 -0500 )edit

To correct the previous comment: When I cut down all of that code and just use cv::cvtColor(data, changed, CV_BayerGB2BGR); I get the Assertion failed error..Thanks for your help BTW

jnj11 gravatar imagejnj11 ( 2015-07-27 09:44:14 -0500 )edit

An update from the vendor: The V034 camera outputs RAW data encapsulated in YUY2 format. Since UVC standard has no RAW image format, we use YUY2 as the wrapper.

jnj11 gravatar imagejnj11 ( 2015-07-27 11:48:12 -0500 )edit

Have you seen this? It is a little bit outdated, but that is the idea: use the flag, see if it works.

thdrksdfthmn gravatar imagethdrksdfthmn ( 2015-07-28 02:21:33 -0500 )edit

Yes, I've seen this and it doesn't work either. I've spent the last few days trying everything I can think of. I may have to 1) go back and try everything again 2) try something other than opencv

jnj11 gravatar imagejnj11 ( 2015-07-31 15:28:20 -0500 )edit