# Questions tagged [shape-analysis]

The tag has no usage guidance.

33 questions
Filter by
Sorted by
Tagged with
11 views

### How to accurately pinpoint multiple overlapping circles in image?

I have binary bitmap images (medical annotation overlays) where sometimes multiple circle perimeters are present which are overlapping. I need to extract the individual center and radius for each ...
53 views

### How to determine the shape along which an object is moving [closed]

The object moves as it pleases and receives its GPS coordinates. How to determine which shape the object is moving along? For example, we accumulated 10 points, processed them and produced the result: ...
38 views

### How to create a single variable describing these peaks?

First, I would like to point out that I am a complete outsider to the field of signal processing, so please bear with me and go easy on the jargon :) I nevertheless decided to post here, because I ...
71 views

### Need a similarity metric that describes these two curve as highly similar

I have a large number of time series data and I need to be able to compare the similarity of the curves to a reference curve. The reference curve in question is shown in red in the figure, and I'd ...
18 views

### Sampling points on a face of a human body mesh

Is there a known shape analysis technique to sample points of a not necessarily naked human body mesh (more specifically the head part). The goal would be to randomly sample (uniform distribution) ...
88 views

### Typical shape detection algorithms

Here is my target, given a set of consecutive discrete 1-d data points within a window. I want to know whether there are good algorithms to detect certain typical shapes of the signal in the window. ...
12 views

### Comparing two meshes obtained using Structure from motion

I'm trying to find some literature about the following problem, but I'm not entirely sure what to look up. Suppose you have an object that you manage to re-construct using structure from motion at ...
99 views

### How to find position, scale and rotation of a known shape/contour in an image?

I have an image of an object. The image shows a high contrast outline of the object. It is guaranteed that the image shows exactly one object. The shape/contour of that outline is known. It is not ...
65 views

### morphological processing : Hit or Miss shape detection

I am currently looking at shape detection for Hit or Miss. I am having a bit of trouble with the concept of the window that they have you to detect the shape. Up till now reading about hit or miss ...
30 views

### How to change the shape of a function generator keeping the rate?

I'm making a sort of Envelope Function Generator. At the moment, I'm calculating only the the "rise" stage, which goes from 0 to 10 V; than, brutally, I back it to ...
398 views

### Selecting gradient orientation for Generalized Hough Transform while scaling and rotation is present

I am using this link to study Generalized Hough Transform. I will explain it briefly. In order to detect a shape, an R-table is created for the shape with $\phi$ indicating gradient orientation for ...
58 views

### Estimating the deformation of a printed label in an image

For a university honours project, I am developing an algorithm to read the text on nutrition labels. One difficulty I have encountered is how to 'flatten' the text in images of labels that are very ...
34 views

### What is the most reliable shape representation for the purpose of detecting humans shapes?

The requirement of the algorithm is to detect human shapes. While the standard HoG or Harr cascade can be used, I am exploring whether the human shape - which primarily includes face+neck+upper-torso ...
102 views

### Video: Who crossed the finishline first?

Okey, so there was a boat race during the weekend. It was a very tight race, but a few minutes after the race, the green boat was declared winner. Given only this video images, how can they ...
62 views

### How to recognise different symbols from their slope ? like (<,>,^) etc

i am trying to build a program in which user input a symbol with mouse and program recognise the symbol by saving mouse coordinates in array ,for this i have followed following steps: Firstly check ...
207 views

### What is a good algorithm, and framework, to calculate centres of gravity or mass (cog)? [closed]

I'd like to take an photograph, subdivide it into a tesselation, either of squares, or (ideally), hexagons, and then find the centre of gravity (or, if you prefer, centre of mass) of each cell of the ...
209 views

### Non-symmetrical lemniscate curve parameterization

I'm trying to fit a function to data points. The data generally resembles a butterfly/lemniscate shape, see drawing. The problem is that the shape in my data can be rotated, skewed and/or non-...
710 views

### Poster detection in OpenCV?

I'm really new in image processing, so please sorry I'm a newbie. I tried to use the squares.cpp for detecting posters (since they usually are rectangles) without using expensive feature detectors (...
664 views

### How to calculate particles sizes for spheric particles with overlapping and superposition? (Example image included)

I'm trying to automatically calculate particles sizes histogram for images like this one: Common threshold and segmentation doesn't seem to work. What filters and algorithms do you suggest to be used?...
244 views

### Shape of Kaiser windowing function FFT response

I'm trying to determine the shape of the FFT response of a signal which had a kaiser windowing function applied to it. What I mean by this is if the shape is a normal bell curve or a Lorentzian ...
309 views

### How to efficiently calculate points of intersection of a straight line and a contour?

Ex. I have an image, let's say 100x100 pixels with some shape on it. And a set of straight lines that are passing through origin located at some point of image, for example origin located at point (...
1k views

### Possibilties of chebyshev polynomial waveshaping

When talking about harmonic distortion, or more specifically waveshaping, we say the order of distortion, can be solved from the equation: $x^n$ Where n is the order of distortion. To my knowledge ...
119 views

### Processing and feature extraction from very short signals

I recently have encountered very short time signals (from three to 12 samples, typically). They appeared for instance in small time frames in engine simulation that should be extrapolated in a robust ...
3k views

### Fourier descriptors: trying to classify objects

Describing my background: I have around 33 items labeled. For example, 3 pictures of the contour of a basil plant, 4 pictures of the contour of earphones, 7 of a mug, etcetera. I'm trying to ...
1k views

### Shape recognition, hough transform

I'm trying to match a picture saying "this is ducks, this is towers" by giving votes from the hough transform of a picture. I've found this article http://ttic.uchicago.edu/~smaji/papers/hough-...
5k views

### Zernike Moments' implementation in OpenCV

The reason why Hu moments were implemented in OpenCV and why Zernike moments were not implemented is looking like their performance similar as stated in this paper. As stated in the paper Zernike ...
2k views

### MPEG-7 descriptors' implementation in OpenCV

I'm looking for implementation of MPEG-7 descriptors which are compatible with OpenCV's recent versions and containing "region-based shape descriptor ART(Angular Radial Transformation)". I ...
193 views

### Optimal way for curve detection

I am totally new to image recognition and image analysis and have a project concerning detecting a smooth curve on a uniform background (white/black/any color) and then be able to follow this curve ...
143 views

### How to estimate gradient orientation?

I have a general task of discriminating images of shaded cylinders that significantly vary in 3d orientation, and almost insignificantly in size and shape. I have treated it as a regression problem ...
181 views

### Classifying 2D shapes by the smoothness of their boundaries

I'm doing image analysis, and I want to classify smooth objects (has smooth boundaries) from non-smooth objects (has zigzag-like boundaries). Which feature should be fed into ML framework? What are ...
5k views

### How to fit an ellipse to 2D data

I'd like to find the "best" fit of an ellipse to contiguous, possibly concave shapes such as: What have I tried? I thought that one could assign the direction of the major and minor axes \$\vec a, \...