Community Profile # Stewart Tan

32 total contributions since 2019

• View details...

Contributions in
View by

Question

Problem with Matlab gui quitting
So i want to create a gui which is basically a timer which counts down from 30 minutes. Which is something like above. Whenev...

1 month ago | 1 answer | 0

### 1

Question

Filtering binary image object based on area
I have a binary image below: and the four straight objects are trees which i want to keep and the blob below is an unwanted o...

2 months ago | 1 answer | 0

### 1

Question

Pre-initialise parallel pool
So I’m using Matlab’s parfor for performing feature extraction. However, I find that every time when the code is ran for the fir...

2 months ago | 0 answers | 0

### 0

Question

How do I measure the area of objects in a binary image, to be passed into the function bwareafilt?
So i have a binary image below: and what I want to do is to extract the two smaller rectangle-like object from the binary ima...

2 months ago | 1 answer | 0

### 1

Question

Variance between two vectors
I have two vectors: testvec1 = [4.3 9.1 3.3 7.7]; testvec2 = [8.1 3.2 5.4 8.5]; and i want to calculate the variance between ...

2 months ago | 1 answer | 0

### 1

Question

Gaussian pyramid vs imresize
I've been using imresize frequently to downscale an image of high resolution to about a quarter a lot, but after doing some rese...

2 months ago | 1 answer | 0

### 1

Question

How do i generate a rotation matrix iteratively.
I have two matrices containing coordinates: example1 = [1 3; 4 5; 2 3; 6 17]; ...

2 months ago | 2 answers | 0

### 2

Question

Rotating a coordinate with a rotation matrix
So I'm working with a rotation matrix, basically trying to simulate Where and are coordinates. H is a transformation matri...

2 months ago | 1 answer | 0

### 1

Question

Counting number of same neighbourhood pixels between two matrices.
So i have two made up matrices, which represents an image block. p1 = [4 7 1 2; 4 5 3 1; 8 9 1 10; 8 19...

2 months ago | 2 answers | 0

### 2

Question

Polar coordinates of image.
So i have used the cart2pol() function to obtain the polar coordinates represented by and . In a paper I'm analysing, it is sai...

2 months ago | 2 answers | 0

### 2

Question

Bug in matrix indexing?
So i have the matrix below, which are the DCT coefficients for an image. test = 1.0e+03 * 1.1506 -0.0094 -0.00...

2 months ago | 2 answers | 0

### 2

Question

Creating masks for objects in an image
I've seen some people who managed to create a mask for objects in an image and I would like to know how it's done. For example, ...

2 months ago | 1 answer | 0

### 1

Question

Find rows in matrix based on columns value
If i have a matrix: mat = [1 2 3 4; 5 6 7 8; 9 10 11 12]; How do i find the row index where the column has v...

2 months ago | 3 answers | 0

### 3

Question

Inverse dct in matlab
So I want to remove the higher frequency dct from an image and reconstruct it, so i followed an example by Matlab https://www.ma...

2 months ago | 1 answer | 0

### 1

Question

Comparison between elements of matrix of different data type
So I recently wrote a few line of code to compare adjacent pairs of a matrix where the values in the matrix are integers: test_...

3 months ago | 1 answer | 0

### 1

Question

Problem with using imbinarize in matlab
I want to convert this image to a binary image I tried the following: img = imread('Oval_H.png'); img = rgb2gray(img); img...

3 months ago | 0 answers | 0

### 0

Question

Checking for existence of row in a matrix
I have a sample matrix where: my_mat = [1 2 4 5 3 1 6 9 7] and what I'm trying to do is to check my_mat ...

3 months ago | 1 answer | 0

### 1

Question

Is it possible to add row vectors into a matrix with a for loop?
I wonder if it's possible to add rows of a matrix one at a time with a for loop? Example, if i initialize a blank matrix: mat =...

3 months ago | 1 answer | 0

### 1

Question

Coordinate system of matlab
I drew a visualization below (sorry for bad drawing) and its an 800x533 rectangle. Correct me if I'm wrong, but in Matlab, th...

3 months ago | 1 answer | 0

### 1

Question

Printing row index or row of a matrix by searching for a particular value?
I have a matrix: mat = [ 4 8 5 3; 31 4 5 3; 8 3 1 5]; and I want to display the row index or row of the matri...

3 months ago | 1 answer | 0

### 1

Question

Euclidean distance of adjacent pairs of matrix
So i have an example matrix A = [10 20 30 45 32 94 21 15 67 33 22 54 13 27 89 73] and i want to calculate th...

3 months ago | 2 answers | 0

### 2

Question

Confusion on total number of blocks produced after splitting image into overlapping blocks.
So apparently i found out about the principle that states the total number of blocks produced from splitting an image into overl...

3 months ago | 1 answer | 0

### 1

Question

Performing operations on row elements in a matrix
So I'm creating some simple examples on trying to perform operations between rows in a matrix such as division. I have a matrix ...

3 months ago | 1 answer | 0

### 1

Question

Transferring cell array elements into a matrix
I have a cell array: test_ca = {[1 2 3],[4 5 6];[7 8 9],[10 11 12]} and i want to transfer these matrices in the cell array in...

3 months ago | 1 answer | 0

### 1

Question

Which part of the DCT matlab example performs quantization?
In the link, https://www.mathworks.com/help/images/discrete-cosine-transform.html it is mentioned that "The input image is divi...

3 months ago | 1 answer | 0

### 1

Question

Difference between blockproc() and for loop method of splitting an image with overlap?
So I'm required to split an image into overlapping blocks of 8x8 and 4x4 pixels overlap, and perform dct on each block after tha...

3 months ago | 1 answer | 0

### 1

Question

Blockproc error when including BorderSize argument
I'm working on the exercise by Matlab on dct https://www.mathworks.com/help/images/discrete-cosine-transform.html and i ran the...

3 months ago | 1 answer | 0

### 1

Question

Does blockproc() divide the image into overlapping or non-overlapping blocks?
So I'm exploring ways to split an image into blocks and applying DCT on each blocks of the image and i came across this example ...

3 months ago | 1 answer | 0

### 1

Question

Converting cell arrays back to matrix
So i have a matrix: my_mat = [10 5 6; 2 4 8; 1 20 50] and i used the function 'num2cell' to convert the matrix above into a ce...

3 months ago | 1 answer | 0

### 1

Question

What is the difference between splitting an image into overlapping and non-overlapping blocks?
I'm new to image processing with matlab and I'm currently working on splitting an image into non-overlapping blocks but I've cam...

3 months ago | 0 answers | 0