2020-12-03 07:08:30 -0600 | commented answer | Pixel-wise matrix multiplication berak is right. Use cv::transform, you misunderstand the documentation. |
2020-11-01 07:51:13 -0600 | commented question | How to undistort image along single axis If you have your distortion maps, remap doesn't care what you give it. So pass an iota image (rows or cols) for the dime |
2020-10-20 12:26:53 -0600 | commented question | Is there a way to make this template matching faster? Look at using FFT/DFTs. They transform convolution to element-wise multiplication, offering a huge speedup over spatial |
2020-10-12 15:06:07 -0600 | commented question | Track black object with optical flow Look at median flow paper. There is apparently no benefit to using GFFT or FAST. You must also use more than one feature |
2020-10-09 09:43:47 -0600 | commented question | Calculating motion of Spacecraft/Camera The number of pyramid levels may be insufficient for the distances required going from image 1 to image 3. You might als |
2020-10-09 09:43:28 -0600 | commented question | Calculating motion of Spacecraft/Camera You number of pyramid levels may be insufficient for the distances required going from image 1 to image 3. You might als |
2020-10-09 09:41:07 -0600 | commented question | Drawing several circles in an additive way You could do blending over ROIs, maintaining a total light image. So rather than call cv::circle() directly on the image |
2020-10-09 09:30:58 -0600 | commented question | ORB Keypoints Minimum distance? Do you need a multi-scale detector? Are your images at the same scale? If so, just use FAST for detection and FREAK for |
2020-10-08 08:13:40 -0600 | commented question | ORB Keypoints Minimum distance? Orb does multi-scale FAST, are you sure the points in close proximity aren't at different scales? Is non-maxima suppress |
2020-10-01 11:36:14 -0600 | commented question | crash in Mat::release() Why do you put & in front of channel argument? There is usually no reason to pass cv::Mat pointers. |
2020-09-30 19:20:28 -0600 | commented question | crash in Mat::release() Do not call release(), let it go out of scope. |
2020-09-30 19:18:00 -0600 | edited question | crash in Mat::release() crash in Mat::release() Hi, I have a function that creates a histogram: double median_(const cv::Mat& channel) { |
2020-09-28 06:49:21 -0600 | commented question | I wanted to export my satellite image to a particular zoom level Have you tried using GDAL directly rather than OpenCV? It will offer you all possible features compared to what little i |
2020-09-21 15:00:04 -0600 | commented question | How to pre-process images for OCR ? A Generalization of Otsu's Method and Minimum Error Thresholding. See the end of the paper for Python code. |
2020-09-16 09:00:43 -0600 | commented question | world coordinates from object detection If the camera is (0,0,0) of your coordinate frame, use cv::reprojectImageTo3D(). This requires the Q matrix from calibra |
2020-09-14 18:55:36 -0600 | commented question | Mat of int64 Try something similar to the following: // // This is a deep copy, OpenCV has no CV_64(U|S) types, only CV_32S: // cv:: |
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2020-09-14 14:35:22 -0600 | commented question | Mat of int64 As I said above, there is no int64 support in cv::Mat. Have you measured the performance costs of casting to int32? It m |
2020-09-14 11:42:23 -0600 | commented question | world coordinates from object detection Please elaborate on 'world coordinates'. |
2020-09-10 07:22:28 -0600 | commented question | Convert Images (cv::Mat) You need to scale the results, so multiply or divide by 255 or 65536, etc. Look more closely at that function. |
2020-09-09 08:29:23 -0600 | commented question | How to use opencv demosaicing It that case it looks right to me except that you might have rows and cols swapped. Are you seeing a problem? If so, can |
2020-09-08 18:49:23 -0600 | commented question | How to use opencv demosaicing If you can capture from the camera at 16-bits (even if dynamic range is 12-bits), that might be the simplest and best op |
2020-09-08 14:02:30 -0600 | commented question | How to use opencv demosaicing If your raw data is 12-bit pixels, interpreting them as 16-bits is not going to work and may seg fault. You need to firs |
2020-09-05 09:22:39 -0600 | commented question | Mat of int64 At present there is no CV_64S support, so your best option is to convert/cast to CV_32S for down stream processing. |
2020-09-01 09:28:23 -0600 | commented question | Haar Cascade or ...? OpenCV detection Everyone will answer "deep learning", Haar cascades will almost certainly not work for anything close to what you say yo |
2020-08-24 08:19:45 -0600 | commented answer | normalization not working Your image is 8-bits, 0-255, so normalizing with minmax 0-255 will likely do nothing. 0 will still be 0 and 255 will sti |
2020-08-24 08:15:29 -0600 | commented question | One Hot Encode function No, this is how to make best use of the OpenCV API to get what I want with simplicity. |
2020-08-22 08:18:50 -0600 | commented answer | normalization not working The image is 8-bits so values should already be 0-255, right? The operation won't change pixel values. |
2020-08-21 09:34:24 -0600 | commented question | Crop/approximate contours A few erodes followed by some dilates will coarsen the contour. |
2020-08-18 10:30:38 -0600 | commented question | One Hot Encode function @berak, yes, this could be a 1D loop assuming continuous. The reason is to do this is for semantic segmentation. I have |
2020-08-18 10:29:26 -0600 | commented question | One Hot Encode function @berak, yes, this could be a 1D loop assuming continuous. The reason is to do this is for semantic segmentation. I have |
2020-08-18 09:42:15 -0600 | asked a question | One Hot Encode function One Hot Encode function I have a matrix where each element is a class ID. I need to transform this matrix into a one-hot |
2020-08-07 09:57:47 -0600 | commented question | Optimize CSRT tracker? Another option is tracking by detection, where you run your insect detector every X frames and associate new detections |
2020-08-07 09:53:16 -0600 | commented question | Disable file system cache during imwrite Is this really an OpenCV issue? What do you mean by system buff/cache? Memory? Can you post a minimal example of your co |
2020-08-05 22:50:17 -0600 | received badge | ● Good Answer (source) |
2020-07-27 08:25:50 -0600 | commented question | OpenCV Noisy Disparity Map from Stereo Setup I was just wondering why resize if not for the disparity computation, but maybe they are very large and want to see them |
2020-07-25 11:56:14 -0600 | commented question | OpenCV Noisy Disparity Map from Stereo Setup They are also vertically misaligned. Recalibrate and visualize the undistorted and rectified images as an anaglyph to ve |
2020-07-25 09:17:53 -0600 | commented question | OpenCV Noisy Disparity Map from Stereo Setup Your left image is out of focus. You don't used resized images in the SGBM computation? Your SGBM parameters are a littl |
2020-07-20 12:02:58 -0600 | commented question | Calculate (ORB) descriptors for arbitrary image points Take a look at the source code. For instance, copy and modify the function ICAngles to suit your needs. |
2020-07-06 09:14:18 -0600 | commented question | How to calculate disparity image for Left to Right from Right to Left andvice versa? DSI = Disparity Space Image (HxWxD). This is the volume you aggregate over for a smoothed cost estimate. This is also th |
2020-07-02 14:04:00 -0600 | commented question | How to calculate disparity image for Left to Right from Right to Left andvice versa? If you have a DSI, every comparison you need to do R-L you already did for L-R. |
2020-07-02 07:58:49 -0600 | commented question | How to calculate disparity image for Left to Right from Right to Left andvice versa? If you have a DSI, every comparison you need to R-L you already did for L-R. |
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2020-06-11 15:36:21 -0600 | edited answer | how could I change memory layout from hwc to chw ? The following has worked well for me, with no unnecessary data allocation: void hwc_to_chw(cv::InputArray src, cv::Outp |
2020-06-11 15:35:24 -0600 | edited answer | how could I change memory layout from hwc to chw ? void hwc_to_chw(cv::InputArray src, cv::OutputArray dst) { const int src_h = src.rows(); const int src_w = s |
2020-06-11 15:34:09 -0600 | edited answer | how could I change memory layout from hwc to chw ? void hwc_to_chw(cv::InputArray src, cv::OutputArray dst) { const int src_h = src.rows(); const int src_w = |
2020-06-11 15:32:58 -0600 | edited answer | how could I change memory layout from hwc to chw ? void hwc_to_chw(cv::InputArray src, cv::OutputArray dst) { const int src_h = src.rows(); const int src_w = |
2020-06-11 14:54:12 -0600 | marked best answer | Broadcast single channel to N-channels Is there an OpenCV function to take a single channel image and extend it to N-channels, copying/repeating the pixel value to all channels, something like a pixel-wise broadcast? I need to be able to per-element multiply a single channel image with an n-channel image and the only way to do this with high-level function calls is to extend/repeat the single channel image to match the dimensions of my n-channel image. Can I achieve this with a |
2020-06-11 14:54:02 -0600 | answered a question | Broadcast single channel to N-channels I solved this using cv::transform(), see the example below to extend the single_channel image to n channels. cv::Ma |
2020-06-11 14:46:00 -0600 | answered a question | how could I change memory layout from hwc to chw ? void hwc_to_chw(cv::InputArray src, cv::OutputArray dst) { const int src_h = src.rows(); |