Questions tagged [matlab-cvst]
The Computer Vision System Toolbox in Matlab.
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5 views
What do function deepDreamImage() actually do in Matlab? [Matlab]
The official document mentions that using deepDreamImage(net,layer,channels) we could visualize network features.
I am training VGG16 using Transfer Learning on a dataset of mine for three different ...
0
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0answers
28 views
Processing spectral data in matlab
I am trying to calculate Chlorite Spectral Maturity (CSM) and Illite Spectral Maturity (ISM) scalars using the below formula. So far I have been able to read my data using the below matlab script but ...
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0answers
33 views
I have to calculate optical flow over all the frames in the video while I am Getting optical flow for last frame of video only Why is it so?
I am computing optical flow over an video and plotting the results over the corresponding video frame but i am getting only the last fame in the video by using the given code. I am intended to compute ...
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0answers
26 views
connecting Java GUI with Matlab
I am doing a project where matlab will do the image embedding, water marking, encryption and decryption using AES algorithm. I have developed a gui using java swing which will allow user to select the ...
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0answers
28 views
Plot multiple 2d arrays on top of each other, Matlab
I need to plot (in Matlab) three 2d arrays with the following requirements:
the arrays are - a grayscale image and two different binary masks to be plot on top of each other.
the masks can cross, ...
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2answers
47 views
Matlab - Applying a function in a neighborhood
Lets say that I have a 250*250 matrix. What I want to do is select a [3 3] neighborhood around every pixel and apply a function to it. Now the problem is that the function will output a 2*2 matrix for ...
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1answer
68 views
How to Convert Symbolic Transfer Function into zero-pole transfer function?
I am trying to convert my Symbolic transfer function (e.g. (m.s^2+c.m.s+c.m^2)/s^3+2.m.c.s^2+2.c.s-c^2.m) into zero-pole form like [((s-c/m)(s-2.c.m))/(s-cm)(s-m/2.c)(s-cm)] by using command tf2zp ...
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29 views
In MATLAB, why does delaunayTriangulation give different number of triangles for images with 68-landmarks?
I am trying to implement pose normalization for face images using piece-wise affine warping. I am using delaunayTriangulation to construct face mesh based on detected 68 landmarks for two images: one ...
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87 views
Matlab. How to implement tracking with counter on top of boxes?
Hello I have tried using the example in
https://www.mathworks.com/help/vision/examples/tracking-pedestrians-from-a-moving-car.html and now I want to add a counter to replace the score. I have tried ...
1
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1answer
182 views
Matlab, vision.peopledetector with Motion-Based Multiple Object Tracking?
I have been researching methods to detect people only in the video from a security camera. I want to use vision.peopledetector with vision.BlobAnalysis and vision.ForegroundDetector. But it doesn't ...
2
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1answer
245 views
Intersection over union but replacing the union with the minimum area in MATLAB
I'm trying to find intersection over union over 2 overlapping images and it works fine.
iou = area of overlap / area of union
Now, when I was referring this document - https://www.mathworks.com/help/...
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47 views
Can we use pixel location as feature in feature vector?
I'm working on a pixel based problem. I'm using different feature descriptors. My question is can I include pixel location as a feature with other feature descriptor?
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0answers
17 views
Neural network for bags-of-visual-words giving a pretty bad training/testing results
I created a feature matrix using (encode, bagOfFeatures functions) visual-bags-of-words using computer vision toolbox, it is 500 x 14404 (Xtrain = 10793, XVal = 1204 and XTest = 2407 samples). There ...
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0answers
68 views
Visual bag-off-features “evalute” vs. fitcecoc classification results are very different
I have few questions regarding vision toolbox's visual bags-of-features class. Firstly, I have a feature matrix created using (encode, bagOfFeatures functions) visual-bags-of-words using computer ...
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1answer
124 views
SIFT features with bagofFeatures
In the Computer Vision System Toolbox the default features extraction is using SURF. How can use SIFT feature extraction using bagofFeatures class? Is there a Custom Feature Extractor available for ...
1
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1answer
173 views
Computing HOG feature on a single point using Matlab “extractHOGFeature” function
I'm confused with matlab "extractHOGFeature" function. I have an depth image (370x89). I want to calculate HOG on single point in an image. When I give the point[i,j] sometime it returns empty vector(...
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1answer
171 views
Computing Histogram of Oriented Gradients on a single point
How does the HOG (Histogram of Oriented Gradients) work on single point in an image? I am using the Computer Vision Toolbox's version of the HOG descriptor: https://www.mathworks.com/help/vision/ref/...
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1answer
61 views
Passing parameters to function handle in bagOfFeatures function
Lets say we have a custom extractor function
[features,featureMetrics] = exampleBagOfFeaturesExtractor(img,param1, param2)
I want to call bagOfFeatures function and pass custom extractor function:
...
3
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0answers
57 views
Modification of path's labelling session file in matlab
I created my own labelling session file in matlab (using training image labeler application) that contrains the original images of my data base. I copied and pasted this file and the data set in an ...
1
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0answers
44 views
Matlab: Extrinsics function on two checkerboards in one image
I am using the extrinsics function for a project that aims to determine distances of objects from the camera that have checkerboards attached to them. This is done for every frame in a video. My ...
2
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1answer
209 views
read disparity map using png file
I calculate a disparity map
d = disparity(imgL,imgR, 'Method', 'SemiGlobal', 'BlockSize', 7);
If I want to save the disparity map in image file
dis1 = d/63; imwrite(dis1,'dis.png');
How to read ...
2
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2answers
159 views
Detecting strongest points on text
I need to find text areas on a natural image.
I = rgb2gray(imread('image-name.jpg'));
points = detectHarrisFeatures(I);
imshow(I); hold on;
plot(points);
Above version of code retrieves all ...
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1answer
339 views
bagoffeatures extract different types of features
I have a problem with the function bagoffeatures implemented in matlab computer vision system toolbox.
I'm doing a study of a classification of different types of images, first of all i'm trying to ...
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1answer
102 views
How integral image influence the result of local binary pattern or center symmetric local binary pattern
I know this looks somehow not related to code errors and development but
I want to know if someone can understand these codes of
integral image and local binary pattern, and tell me how they affect ...
2
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1answer
128 views
runtime error in bundle adjustment example - matlab
I asked it in MATLAB forums but didnt get a response. Hoping someone can answer the question here:
I tried using Bundle Adjustment example at https://www.mathworks.com/help/vision/ref/...
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1answer
289 views
How to plot boundary and centroids on video frames called inside step() function
I am calling some images inside a for loop and then doing some processing on those images. After that, I am using the step function to display those frames and their masks inside a video player. How ...
1
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1answer
135 views
Filtering the DetectSURFfeatures and converting the array back to its own type on MATLAB
I'm supposed to gather a bunch of SURF points from a video frame and after filtering these coordinate points bunch I'd like to convert it back to it's own form.
Below you can see the code I wrote:
...
-1
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1answer
69 views
how to find nearest grid points in the set of data points using matlab [duplicate]
I have (x,y) points and how to find (x1,y1),(x1,y2),(x2,y1),(x2,y2) grid points in the set of data points(xi,yi)...
1
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1answer
92 views
Rectified images of same size as the initial ones
I want to rectify a stereo image pair in MATLAB. To rectify, I use the following call:
[J1,J2] = rectifyStereoImages(I1,I2, cameraParamsStereo);
If I do this, then I only get the so called valid ...
1
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1answer
108 views
Elusive MATLAB built-in function
I am trying to read the following internal MATLAB function:
>>which visionInitializeAndExpandCheckerboard
built-in (C:\Program Files\MATLAB\R2015a\toolbox\vision\vision\...
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1answer
181 views
Plotting using scalar values. (vector/matrix/array input arguments are not accepted by code.)
I'm having a bit of trouble trying to make a 2D plot of a function depending on only one variable. Cutting a long story short, the function can only accept scalar values; it will not accept vectors. ...
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2answers
695 views
Frames of type double must be in the range of 0 to 1: MATLAB
I have a video and I have made a Sobel mask for it on MATLAB. Now I have to apply that Sobel mask on each frame of the video by reading each frame through for loop. The process is something like:
...
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0answers
29 views
How to change the dataset to the format of Progenetix Informative matrix?
I have a fMRI data matrix A, the size of which is 500*3000 double. Here 500 represents the number of observations, 3000 represents the number of voxels.
And I have another label matrix B ...
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2answers
75 views
(New to MATLAB) I want to learn how to use MATLAB to measure distances between features of an image. Where should I start? [closed]
I'm a grad student working on a PhD in a biomedical science and have no coding experience. My university has a campus license for MATLAB so I thought I'd try to learn how to use it to get a more ...
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1answer
469 views
(Matlab) How to modify read only opticalflow object properties
I am using Matlab to analyse video optical flow and what I want to do is weighing the optical flow between video frames.
My problem is I don't know how to modify the read only opticalFlow object ...
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1answer
36 views
I want to calculate the probability of each element occurring in a vector
I have tried it using arrayfun() as follows as answered on stackoverflow:
prob_y = arrayfun(@(x)length(find(y==x)), unique(y)) / length(y)
But the problem with this is that I have to find the ...
0
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1answer
35 views
Displaying Rotatable 3D Closed Shapes
I have a list of x y z points that represent the vertices of a 3 dimensional object (a section of a brain). I would like to be able to visualize it in a 3-D plot with all its surfaces connected. I ...
1
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1answer
79 views
Estimate the amount of the area of the hemisphere’s surface which can be seen by the eye?
We suppose that there are one hemisphere and three triangles in a 3D space. The center point of the hemisphere’s bottom is denoted by C. The radius of the hemisphere’s bottom is represented by R. The ...
4
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2answers
437 views
MatLab: Corner Detection on Binary Image
I am trying to find a way to find the corner points on this binary image in MatLab
I have been trying to find a way to fit a triangle over this image and finding the vertices. I have tried finding ...
3
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1answer
499 views
Fill in a region of a binary image which is not completely closed
In MatLab, I have a binary image and I am trying to fill a hole. The problem is that the area is mostly (but not entirely) closed. Is there any existing visual processing functions that can do this? ...
1
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1answer
77 views
Change checkboard size in Matlab Stereo Calibration App
Matlab Stereo Calibration App only ask the square size once, when adding the first image.
Is there a way I can:
Change the checkerboard square size?
Set different values to X and Y size (rectangles ...
2
votes
1answer
336 views
Understanding extrinsic stereoParameters (rotation) on Matlab stereoCameraCalibrator
Consider the fallowing stereo camera system calibration parameters using matlab stereoCameraCalibrator app.
R1 = stereoParams.CameraParameters1.RotationMatrices(:,:,N);
R2 = stereoParams....
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0answers
46 views
How to display the Rectangles from different frames in one frame?
I am working on a vacant spot detection solution. I am getting the rectangle boxes for different frames in multiples figures, all I want is to display all the detected rectangles boxes in single ...
4
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1answer
281 views
Finding the position of edge defects of a circular object with MATLAB
I have a problem finding defects at the edge of a circular object. It's hard to describe so I have a picture which may help a bit. I am trying to find the red marked areas, such as what is shown ...
3
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1answer
2k views
Calculate object's velocity in video frames - Optical Flow (Matlab)
I can't understand how Matlab calculates the velocity matrix of a video frame by Optical Flow using just the current frame. The velocity wouldn't be a relation of different pixels position varying in ...
2
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1answer
196 views
Index exceeds matrix dimensions when trying to access position vectors
I am simply reading an image and wish to visualize the bounding boxes returned by blob analysis of matlab which returns position vectors.
Here is my code
img = imread(file_name);
img = im2bw(img);
...
0
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1answer
102 views
display images sequence using videofilereader
I try to develop a code (as follow) to display a video from file call 'image' that contain jpeg image frames. However its display and stop until the last frame, which mean the display window is ...
4
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2answers
4k views
How to generate a 3D point cloud from depth image and color image acquired from Matlab
I have 2 set data acquired from kinect
1- depth image with size 480*640 (uint16) from a scene
2- color image with same size (480*640*3 single) from same scene
The question is how can I merge these ...
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1answer
144 views
Wrong rectification in MATLAB
The rectification function in Matlab seems to be responding wrong. Can anyone let me know if I am getting the right output?
Left Image
Right Image
Anaglyph of unrectified images
Anaglyph of ...
2
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1answer
115 views
rectifyStereoImages throwing “Not enough input arguments error”
I am not trying to rectify a pair of stereo images but I am getting a strange error from the function
Error using rectifyStereoImages (line 106)
Not enough input arguments.
Error in ...
