Ulrikop's profile - activity

I want do detect marked spots in the picture of a video recording. Which kind of mark lends itself to find it again as definitely and quickly as possible? Which way is the best for finding these marks or rather the coordinates of the marked spot?

As it can seen in the picture above I already tried three different ways. In all attempts I looked for the center of the marker (intersection at the cross, center of the circle or center of the chessboard). The idea of the first attempt was to calculate the intersection of straight lines. But there are lots of straight lines in such a picture, as for example the ones belonging to the lego brick (which isn't determined to always lay this nicely right in the middle of the four spots). The idea of the two later attempts is based upon calibration. Here I tried to make the spots modeled on the spot-search of calibration with a chessboard or circles.

Unfortunately these attempts weren't as successful as I had expected. Which is why I hope for hints from you as experienced openCV-users.

Thanks a lot.

PS. In case it is of interest: The four spots always demonstrate the corners of a rectangle.

Thanks for the links to the information on the different lenses. That's a very interesting topic. But I am afraid that the prices for such camera-systems might easily rise very high. Or did you think if mounting such a lens onto any old webcam? Because of it being just a small project I would prefer a cheaper solution (about 120 Dollar at most). Ideally I would like to use a camera available in a normal electronics store. Does anyone have an advice on ready-made standard cameras?

Hi, I'm looking for an adequate camera for a project of mine. As I am not very experienced in this field I ask you for your help.

I want to recognize and analyze lego bricks which are transported on a flat conveyor individually (using OpenCV of course). Therefore the lego brick is supposed to be as recognizable and sharp as possible in a close up with a distance of 10-20 cm. Additionally the color should not get falsified, so it remains distinguishable (for support I will take care of ideal lighting conditions - if somebody has any hints on this I would be very grateful too).

My program is running on Linux. There the camera should work without great effort, ideally with Plug and Play. Using OpenCV and Linux makes the control of the focus problematic in most cases. Which is why a manual focus would be of advantage,

In short: Which camera with manual focus is advisable for close ups of small objects?

Thanks for your help!