Am Thu, 7 Nov 2013 13:26:14 -0500 schrieb Gene Heskett <ghesk...@wdtv.com>:
> Hello all; > > I, and several others are attempting to make use of camera vision in > a machine shop environment, to auto position a lathe or milling > machine for instance. > > My current camera is the highest priced of the logitech webcams, with > a nominally 5 megapixel format. > > But for our purposes, the field of view at 2540x19xx is at least 75 > degrees. We need maybe 5 degrees because all we are interested in is > the pixel under the center pixel of the crosshairs. This, when > inspecting the workpiece from 50mm, should represent accuracy's in > the thousandth of an inch category, and would generally be quite > useful to us. > > So, is it possible to setup a framebuffer with 2 circular pointers, > the input pointer writing the 5 megapixel image as it comes in, and > an output pointer that only reads out the central 100x100 pixels of > the image, maybe even 240x240 but for our uses its overkill. > > The problem as it exists now is the processing time for the video > image to get thru camview-emc and actually be presented on our > computer screens, is on the order of 3 to 5 seconds when the whole > signal chain has to deal with the 2540x19xx format of a decent > webcam. If we could throw away all but the mathematical central area > of the image that the rest of the video chain had to process using > only 1 core of a 1.4Ghz atom processor, it seems we could save many > valuable seconds of image processing time. > > The V4L list didn't understand what I wanted, so everything they > suggested threw away resolution which we don't want to do, and gave > the same field of view in the output, but converted to useless fuzz. > Hence I come here in search of help. Effectively, we need extreme > telephoto at maybe 57,600 pixels (240x240 for this example) > resolution, captured pixel by pixel from the central 57,600 pixels of > the input for this application. > > Thank you for any usable suggestions. > > Cheers, Gene This is a job for a camera with a telephoto lens. You're using a camera with the wrong lens, that's all. For many cameras there are telephoto adaptors. Capturing 2540x19xx pixels to get a 100x100 picture is an extremely unreasonable approach. - edgar _______________________________________________ xorg@lists.x.org: X.Org support Archives: http://lists.freedesktop.org/archives/xorg Info: http://lists.x.org/mailman/listinfo/xorg Your subscription address: %(user_address)s