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How to send a binary image over USB

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I am writing a new module in OpenCV. For the most part it is working fine and has fantastic frame rates!

The mapping to launch my code is:

MJPG 320 240 15.0 YUYV 320 240 60.0

As part of this color and shape based tracking script, I generate a binary image through a threshold process. To accurately calibrate the code, I need to visualize the binary image. When I attempt this, I only get a black screen. I believe this is because JeVois can not handle sending a binary image in a MJPG STREAM over USB. Is this correct? Is there a way I can have the binary image displayed over USB?
asked Nov 14, 2017 in Programmer Questions by Billbo911 (1,080 points)

1 Answer

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I answered my own question. I had to convert the binary image with a bit of a hack, to color.

Even though the threholded binary image just has two values for each pixel, 0 and 255, I was able to use:

binOut=c2.cvtColor(binImage, cv2.COLOR_GRAY2BGR)

The resulting image can then be set with 


answered Nov 16, 2017 by Billbo911 (1,080 points)
yes, that is great, or you could stream the GRAY image out by declaring a different videomapping:

GRAY 320 240 15.0 YUYV 320 240 15.0

(generally speaking, it is a good idea to match camera and USB frame rates unless you are indeed processing 4 camera frames for each frame you send out to USB)

and then outframe.sendCvGRAY(binOut)

and finally use a frame grabbing program (guvcview, etc) that can grab GRAY (Y800) video frames.