What I have done : Taken input image and resized image to standard size as I have to compare it with template. converted in binary using threshold value. Detected connected component and display...

Currently I'm working on an app for Android phones. We want to detect features of a face. The programm should be able to detect the positions of the eyes, the nose, the mouth and the edge of the fa...

is there a way to detect if calling play() on a video element is allowed without a user gesture? On Android Chrome this warning is given: Failed to execute 'play' on 'HTMLMediaElement': API can on...

I'm trying to detect keypoints with ORB everything is fine until I switched to Opencv 2.4.9. Firts, it seems that the number of keys decresed, and for some images, no keypoints are detected : Th...

Everywhere in features2D classes I see terms query and train. For example matches have trainIdx and queryIdx, and Matchers have train() method. I know the definition of words train and query in En...

I have a problem with opencv 3: I want to use a feature detector, SimpleBlobDetector, about to use filters by convexity and circularity. But when I try to execute the code, the following error is t...

I was trying to implement the FREAK Descriptor in Python using Opencv. Here is the code i'm using: def surf_freak_detect(image,hessianThreshold): surfDetector = cv2.SURF(hessianThreshold) surfDe...

If there is a given 2d array of an image, where threshold has been done and now is in binary information. Is there any particular way to process this image to that I get multiple blob's coordinat...

I'm looking to identify some peaks in some spectrograph data, and was trying to use the scipy.signal.find_peaks_cwt() function to do it. However, the official documentation I've found isn't too des...

I am undertaking a project that will automatically count values of coins from an input image. So far I have segmented the coins using some pre-processing with edge detection and using the Hough-Tra...

I am using sift algorithm from python extra modules for some feature matching. Although one thing I did not understand is the concept behind the normType passed to the BFMatcher. i.e Which ones hav...

I was trying to match two images using OpenCV ORB as explained in this tutorial. Here is my code: import numpy as np import cv2 import six import pyparsing import dateutil from matplotlib import ...

I need the feature detection algorithm. I'm fed up surfing on the web finding nothing but SURF example and hints how to do that, but I did not find an example with other than patented descriptors l...

According to my research: "WebView" can disable "opening links in new windows/tabs". WebView is used by native app developers to display webpages within their app(see Twitter's app). Detecting W...

Reading EmgCV docs cant quite understand: what detectors can be used with which DescriptorExtractors? Here it is said: You can use it with the FREAK descriptor that is scale invariant. Just repla...

I need to get the list of the x and y coordinates of the pixels that the feature matcher selects in the code provided. I'm using Python and OpenCV. Can anyone help me? img1=cv2.imread('DSC_0216.jp...

I need to detect the different shapes on the image such as ellipses and circles with a dashed-border. Using OpenCV causes some troubles, for e.g. openCV detects not a contour but an amount of smal...

I am new to the concept of Biologically Salient Regions Detector, and I read some papers and they always use the mechanism of Center-Surrond to computer features intensity, color and orientation. I...

I am implementing stereo matching and as preprocessing I am trying to rectify images without camera calibration. I am using surf detector to detect and match features on images and try to align the...

I'm trying to detect circles with using hough transform. With my current code I can detect the one below But I want to find black hole inside the circle I've detected. however changing param...

I am doing some research in Local Feature representation, so SIFT, SURF and such. Now, has anybody here ever tried BRIEF and ORB? If so, can you discuss what are some of the pro and con with respe...

I was unable to find good explanations at one place on the internet. There are too much stuff and instead of finding out what to do, I get more confused. My goal: Create an Android application th...

I want to detect the 4 corners of the document in android. Iam using opencv library. Iam using the following approach- (1) grayscale the image (2) Apply median blur (3) Apply adaptive threshold (4...

I want to use the svm classifier for facial expression detection. I know opencv has a svm api, but I have no clue what should be the input to train the classifier. I have read many papers till now,...

i'm trying to evaluate SIFT and SURF Detectors by Repeatability criteria. i find out that below method can find Repeatability ,Correspondence of SIFT and SURF cv::evaluateFeatureDetector(img_1c,...