Hi Hector, On Tuesday 11 March 2008, Héctor Hugo Avilés Arriaga wrote: > Dear all, > > I'm a newbie in all this webcam stuff and trying the Luvcview source code. > Luvcview is useful to me because it allows to display images from two > videcameras at the same time. Doing the same with OpenCV retrieves > corrupted images. > > I want to access the pixel information. I'm able to convert > YUYV format to 24RGB easily using the Pyuv422torgb24 function, > and the display the images using a 24bits BGR format directly.
You should contact Michel Xhaard for questions related to luvcview internals. He is the luvcview author. > Unfortunately, I cannot do the same with the MJPEG format. > I realize that the image is decompressed into the > videoIn->framebuffer buffer before displaying it, but I don't know how to > access the pixel information correctly. > I have tried to copy the image into an OpenCV buffer in this way: > > opencv->imageData[curr_pos] = videoIn->framebuffer[curr_pos++]; // B > opencv->imageData[curr_pos] = videoIn->framebuffer[curr_pos++]; // G > opencv->imageData[curr_pos] = videoIn->framebuffer[curr_pos++]; // R > > However, all I see are vertical lines and > my silhouette repeated three times on the image. > As you can see, I'm assuming this information is stored in BGR format > in the videoIn->framebuffer. > > The questions are: which is the correct form to access the information > captured with the MJPEG format? and, using this format speeds up the > capturing process after all? I'm not familiar with the luvcview code, but the data might be stored after decompression in YUV format instead of RGB. Just a wild guess. Best regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
