Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [object-recognition]

90 questions
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Scale and Rotation invariant feature descriptors

Can you list some scale and rotational invariant feature descriptors for use in feature detection. The application is for the detection of cars and humans in video captured by a UAV, using a multi-class classifier. So far I have been looking at SIFT…
Jono Brogan
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Pedestrian counting algorithm

Currently I am developing a pedestrian counter project (using OpenCV+QT on Linux). My idea about the approach is: Capture Frames Do Background Subtraction clear noises (erode, dilate) find blobs (cvBlobslib) - foreground objects For each blob, set…
bahadir
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Apply a Gabor filter to an input image

I tried to apply a Gabor filter with a specific scale (according to my values of lambda and sigma, so it is (7x7) and for 4 orientations (0, $\frac{\pi}{4}$, $\frac{\pi}{2}$ and $\frac{3\pi}{4}$) to a input gray scale image. In my code, three steps…
Liszt
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Detecting a filled glass object

I've been sent here from this question in stackoverflow, please excuse me if the question comes too specific and it's not in the manners in here:) The task is to find a glass with specific liquid in it. Let me show you the pictures and then describe…
user1916182
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Removing Noise from Dental Radiography

I'm working on a project of applying Active Shape Model to locate tooth in dental radiograph. For those familiar with the technique, I'm currently trying to sample along normal vectors for each landmark. The paper recommends to take derivatives of…
Raven
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Vehicle segmentation and tracking

I've been working on a project for some time, to detect and track vehicles in video captured from UAV's, currently I am using an SVM trained on bag-of-feature representations of local features extracted from vehicle and background images. I am then…
Jono Brogan
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Good features / algorithms for recognizing car-models in images

I have a question concerning object recognition, especially recognizing car-models! I am at the beginning of a work about identifying the same car-model in different images. At the moment I think one of the best algorithm for 3D object recognition…
jstr
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3 answers

Gesture recognition using only simple techniques

I'm following a computer vision course and I have this exercise: write a program that, given an hand image, it can recognize if the hand is open, closed, in a punch, or holding an "ok" posture, using only the techniques provided till now (pixel 4/8…
nkint
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OpenCV detectin skin colour invariant with illumination changes

I have to capture skin colour independent of illumination. I used the following criteria(using hsv and rgb) but it ain't working: int h = get_hue(...); int s = get_saturation(...); int r = get_red_component(...); int g =…
Roney Island
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Object detection versus object recognition

I have a slight confusion differentiating between object recognition and object detection. Some people say object detection is a sub-topic of object recognition? Can someone clarify the the difference between these two topics? To the best of my…
user2867655
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How are Object Recognition and Content-based Image Retrieval interlinked?

I need help on understanding the linkage between Object Recognition and Content-based Image Retrieval. Does OR use CBIR to find similar objects with the help of algorithms like SIFT etc or does CBIR use OR to improve its results on finding images…
jstr
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Alternative to support vector machine?

I have to make comparison between 155 image feature vectors. Every feature vector has got 5 features. My image are divided in 10 classes. Unfortunately for using support vector machine i need at least 100 images for class, There is any alternative?
postgres
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What is a good distance measure for matching SIFT descriptors depending on the distribution of their noise?

I have read some papers about distance measures like Euclidean, Manhattan or Chi-Square for matching gradient based image descriptors like those computed from the SIFT Algorithm (128-D vectors). Most of them state, that one or the other measure is…
jstr
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Easiest Pattern to Recognize with Machine Vision

I need to detect the exact position of some kitchen tools using machine vision. I've the possibility to label the tools with a pattern, to make the detection (more specifically the image segmentation) easier. What is the easiest pattern to detect…
Rexcirus
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How to construct descriptors for irregularly shaped image patches

As hinted in this answer, Perceptual hashing is a way to ascribe comparable measures (hashes) to images (rectangular patches). The images do not need to be the same size, and can be slightly distorted, according to the answer. I might soon need a…
penelope
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