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Spandan Tiwari

MathWorks

Active since 2012

Professional Interests: Image Processing, Computer Vision, Machine Learning,Signal Processing, Pattern Recognition, Partial Differential Equations

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Answered
Is medfilt2 a zero-phase filter?
medfilt2 is a median filter, which is a non-linear filter. So, no, it cannot be considered a zero-phase filter.

9 years ago | 0

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Answered
What is moments of image?
Your question is very broad to be answered fully here. There are many tutorials on Zernike moments that you can find online with...

9 years ago | 0

Answered
How to use filter
The classical homomorphic filtering might be able to help here. See the following blog post on the blog Steve on Image Processin...

9 years ago | 0

Answered
sharpening image and removing noise
Also for the image sharpening part, you can use the function IMSHARPEN in the Image Processing Toolbox. It has parameters that y...

9 years ago | 0

Answered
blood vessel segmentation help
This may not be directly relevant but since you mentioned FCLAHE I wanted to point out that the ADAPTHISTEQ function in the Imag...

9 years ago | 0

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Answered
Calculating the number of pixels inside a freehand region.
Since you are already using imfreehand, you can use the method named createMask available in the imfreehand object to rasterize ...

9 years ago | 0

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Answered
Radius precision of circles when using "imfindcircles" to find circles?
The 'Phasecode' method inherently supports radius estimation with sub-pixel accuracy, and hence the results have floating-point ...

9 years ago | 0

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Answered
Use of Bresenham line algorithm to generate 1D profiles from a DTM
If you can morph the data into a 2D matrix, say as a 2D image, you can use the function *improfile* from the Image processing To...

9 years ago | 0

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Answered
detecting rectangle in real images
If your rectangle does not change orientation, you can try using normxcorr2 (in Image Processing Toolbox) with the rectangle as ...

10 years ago | 0

Answered
finding of mse and psnr
There's a function named psnr() in Image Processing Toolbox in R2014a for computing PSNR. MSE is also computed on the way to com...

10 years ago | 0

Answered
Exactly Which otsu extension is working at back end of multithresh.m in matlab2013a.
The algorithms are from the paper: Otsu, N., "A Threshold Selection Method from Gray-Level Histograms," IEEE Transactions on ...

10 years ago | 0

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Answered
need matlab code for image texture analysis
You can look at the functions graycomatrix and graycoprops for computing the popular Gray-Level Cooccurrence Matrix (GLCM) text...

10 years ago | 0

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Answered
Help with cropping a binary image?
Use IMCOMPLEMENT to invert the polarity of the binary images so that the object (fist) is white. Then use BWBOUNDARIES to get th...

10 years ago | 0

Answered
How to remove small CLUTTER from images?
BWAREAOPEN assumes that the objects are white. In your case the objects (regions that you want to remove) are black. So first co...

10 years ago | 1

Answered
how to find Windowed Fourier Transform of an image? If possible function script is needed.
STFT computation requires computing Fourier Transform of sub-blocks of the image. You can use fft2() to get Fourier Transform. F...

10 years ago | 0

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Answered
To fill a closed curve
If you can make a binary image for the closed curve, you can use imfill in Image Processing Toolbox.

10 years ago | 0

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Answered
dashed line imrect of imline
Something like this would help you make a dashed line using *imline* . h = imline(); h1 = get(h,'Children'); set(h1(...

10 years ago | 1

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Answered
how to divide into blocks of 8x8 pixels?
The function *blockproc* in the Image Processing Toolbox maybe a natural fit if you would like to do process the image in blocks...

10 years ago | 0

Answered
colour image segmentation using k means
Another alternative could be to use multi-level Otsu's thresholding to get the segmentation. You can use the function *multithre...

10 years ago | 1

Answered
how to compare the color image to another color image in directory?
One way to compare the images quickly would be compute a structural quality metric such as SSIM between the two images. It is a ...

10 years ago | 0

Answered
directional filter for detecting edges on a circle and rectangle
Look at the function IMFINDCIRCLES in Image Processing Toolbox (R2012a onwards) for detecting circles in your image.

10 years ago | 0

Answered
segmentation
No the initial mask can be any shape although it is preferable to start with a relatively smooth shape such as a circle. You...

11 years ago | 0

Answered
Best Segmentation technique for a structurally homogenous image
Try using the new function activecontour in the Image Processing Toolbox that shipped in R2013a. It should be useful for this pr...

11 years ago | 0

Answered
Looking for an implementation of the active contours without edges method which can be/is initialized with multiple contours?
There's a new function in Image Processing Toolbox in R2013a named activecontour which can do Chan-Vese segmentation and can be ...

11 years ago | 0

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Answered
how to cut out circle from an eye image
Can you show some code that you tried.

11 years ago | 0

Answered
Detecting circles in an image.
IMFINDCIRCLES allows you to specify a radius range which can include the entire range of expected radii.

11 years ago | 0

Answered
how to speed up imfindcircles
Two ways to get IMFINDCIRCLES run faster in your code are: 1) Sending in the image at a lower resolution. 2) Use smaller r...

11 years ago | 2

Answered
How can I use imfindcircles in real time video?
Two ways to get IMFINDCIRCLES run faster in your code are: 1) Sending in the image at a lower resolution. 2) Use smaller r...

11 years ago | 0

Answered
Optimize the edge detection
imopen might be more selective in removing segments based on their size.

12 years ago | 1

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Answered
change color "bwperim"
You can change the color by filling the perimeter pixels with a color value instead of a scalar 255. One possible way to do this...

12 years ago | 1