Questions on the image processing capabilities implemented in Mathematica.

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7
votes
1answer
268 views

Counting elements which are inside another element on a different colour channel

I have a 3-channel image which shows red and green points (certain labelled proteins) inside blue regions (cell nuclei). After applying some segmentation filters, the resulting image is as follows: ...
3
votes
2answers
191 views

How can I detect and modify one area of an image while preserving the rest

I have an image with a big black disk bounded by a white boundary in its center. The image contains some other stuff outside of the spot and its boundary. This stuff has colors which include both ...
0
votes
1answer
213 views

How Can I Transform a Colored Image into Pre-defined Matrix?

I am new to Mathematica and I would like to use it to postprocess some of the experimental data I measure. I would like to visualize voltage measurements over a non-uniformly segmented plate. I would ...
0
votes
3answers
98 views

Formatting the output of ComponentMeasurements

I have some code written here which uses ComponentMeasurements to output some data, specifically the one below: ...
1
vote
1answer
121 views

ImageLines Segmented options

I have tried utilising the ImageLines function, and its accompanying Segmented setting. However, the segmentation doesn't appear to allow for its variables to be fine tuned, at least not according to ...
7
votes
1answer
301 views

Removing the edge features of an image while enhancing internal connectors

I picked up the following leaf today while going for a walk. And wanted then to run the same analysis that @Vitaly Kaurov did for rivers under this posting Measuring Fractal Dimensions of natural ...
3
votes
3answers
197 views

Is there a fast method of generating a Standard Deviation image from a frame stack?

Imagine I have a stack of image frames, $(f_1, ..., f_N) \in F$, where each $f_i$ has the same set of $(x,y)$ dimensions. Using these frames, I'd like to create an image where each pixel in the image ...
1
vote
1answer
295 views

Problem with Fourier and InverseFourier function

I have the following code Image[img, ImageSize -> 300] data = ImageData[img]; fdct = Fourier[data] tdata = InverseFourier[fdct]; Image[tdata] but it seems to ...
1
vote
3answers
179 views

Defining a polygon by clicking on an image [duplicate]

Imagine I have some image, $I$, and I'd like to define a polygon by sequentially clicking on the image to define vertices $(v_1, ...) \in V$, where vertices $v_i$ and $v_j$ share an edge if $j = ...
-5
votes
1answer
2k views

Determine the 2D-Fourier transform of an Image

I am new to Mathematica and using Version 8.0. I want to calculate the 2D-Fourier Transform of a digital image and see its Magnitude and Phase Spectrum, and reconstruct it.
2
votes
2answers
201 views

Intersection & Complement operations for lists of Morphological Components?

I have an array of $M$ sets of morphological components corresponding to the same image, however computed in different ways. For example, we might have: ...
1
vote
3answers
321 views

Adjusting the pixel values underlying a morphological component when computing an “IntensityCentroid”

When calculating an "IntensityCentroid" with ComponentMeasurements, i.e. for an image $I$ and set of components $C$, ...
1
vote
1answer
210 views

Selecting morphological components, of a certain size, centered on points of interest in an image

I have a set of points in an image, for example: ...
10
votes
1answer
226 views

Use TextRecognize to grab timestamps from a video frame

I have microscope videos that have a timestamp overlay to them, and it would be great if I could extract this for each frame to add to my metadata. TextRecognize ...
1
vote
1answer
117 views

Is there an easy way to create a “IntensitySquaredCentroid” using ComponentMeasurements?

One of the options in ComponentMeasurements is to compute a centroid based on the pixel values of some underlying image. We can write: ...
1
vote
2answers
197 views

Understanding the coordinate system for ImageTake

I have a point in an image which I can locate by right clicking and using my mouse. Call this point $p = (100,100)$. I'd like to use ImageTake to grab an image, centered on this spot $p$ with $k = ...
6
votes
4answers
3k views

Fitting a two-dimensional Gaussian to a set of 2D pixels

Imagine I have a set of data like the following: ...
0
votes
1answer
114 views

Returning a bounding disk or box centered on a coordinate in a 2D image

Provided a coordinate $c_k$ in a two-dimensional image, how can I return all of the pixels in a bounding disk or rectangle centered on $c_k$ of some specified dimension $d$? Update: Hat tip to Kuba ...
17
votes
1answer
358 views

Color scheme used by Colorize?

The Colorize function is often used to display the results produced by MorphologicalComponents: ...
0
votes
1answer
128 views

Returning lists of pixels connected through their Moore neighborhoods

I have a binarized image in Mathematica 9, and I would like to generate a list of coordinates for clusters of pixels connected through their Moore neighborhoods, e.g. ...
3
votes
1answer
226 views

Volumetric Rendering of cylinder symmetric radial image

I would like to render a cylinder symmetric radial cross-section with Image3D. As an example one could use the propagation of a Bessel Beam through a Lens: Here the cylinder axis is the bottom of ...
8
votes
3answers
422 views

Image Processing: Concrete test blocks

Background Concrete is mixture of aggregates and cement. Aggregates are composed of different sizes and colors. Core samples are taken by drilling in order to test the strength of concrete . They are ...
7
votes
2answers
261 views

Improve TextRecognize on numbers

I have an image contain only numbers, and TextRecognize fail to recognize some numbers: img=; TextRecognize[img] (*826718*) The documentation says that "The ...
0
votes
3answers
392 views

Derive a smooth circle with cusp from an image

question 1 get the center (sample data) sample is the black circle with cusp. ...
21
votes
2answers
947 views

Find radii of concentric circles in image

I have an image of concentric circles, I would like to find the radii of the circles (only the innermost few are important). I've had a go using what I could find in previous posts, but am a bit ...
15
votes
4answers
826 views

Digital filter of image in Fourier space

Consider the contour plot below, of a function f(x,y) - which is calculated numerically by solving some equations. If one looks carefully, one can observe two types of waves, to the left and right of ...
1
vote
2answers
300 views

Image Restoration

I want to degrade the image, and then execute the restoration, such as a lena.jpg. I tried this: ...
5
votes
3answers
292 views

Getting RGBA data from an image

What is going on with returned data in the following examples? It appears ImageData returns different types depending on the what data is passed into ...
15
votes
2answers
500 views

Twirl Image Transformation

I am looking to reproduce the functionality of Photoshop's "Twirl" filter, which twists an image that originally looks like this (pulled from this page): Into this: Ideally, I'd like it to ...
4
votes
3answers
148 views

Maintaining map dimensions after using Colorize

I am trying to beautify a map by using Colorize as demonstrated in the Mathematica documentation. First, I import a shapefile from DIVA-GIS for France which ...
9
votes
4answers
1k views

How do I find the coordinates of points in this image?

I have never used image processing with Mathematica. I need to get the coordinates of the red points from this image I made in Illustrator. Is there a way to get Mathematica to read or detect the ...
138
votes
2answers
56k views

QR Code in shopping cart handle

This week, the market people from my work wanted to put QR codes in shopping cart handles, but when they tested it, the QR code did not work. I noted that the cylindrical curvature (even small) ...
20
votes
4answers
2k views

How can I detect an ellipse in a photo?

I tried to detect the rim of the following cup as an ellipse. I've tried the solutions given in How to find circular objects in an image? to detect the ellipse, but the detection result was not ...
3
votes
1answer
141 views

Resampling when using image as Texture

How to get sharp pixel boundaries with Texture? I'd like to have only black/white in the example below, no gray. ...
2
votes
3answers
255 views

Using ImageTransformation[] with a lookup table

I need to transform images by ImageTransformation in a time critical application. Therefore I precalculate a lookup table lut of ...
0
votes
1answer
132 views

TextRecognize with crosses, circles and spaces results into oddities, why?

I am investigating this answer here about detecting crosses and circles with TextRecognize. I tried to solve this problem here by directly using the builtin command TextRecognize but it does not work ...
32
votes
1answer
935 views

Finding areas of beings in microscopic image

I've got lots of images of diatoms. I need to get a list of their equivalent radii. It's not crucial to get them all, as long as those missed don't mess with the radius distribution (as would ...
14
votes
6answers
1k views

How to find major color in a picture?

I want to find the major color (the color which appears most often) in a picture and do some analysis later. For example, if I have this picture: What I want to do is find out that gray, red, ...
0
votes
1answer
125 views

Outputting a set of graphics 3D objects with positions defined by one array and colors by another? [duplicate]

I have a set of 2- or 3-space coordinates in an array, $(v_1,...,v_N)$, and an array of RGB color values (outputs from ImageValue[]) for each coordinate, $(c_1,...,c_N)$. How can I output a ...
3
votes
1answer
653 views

Detection of horizontal lines in an image

Ok I'm trying to detect horizontal lines in an image. But the problem is that the line is quite obscure. So I'm not sure if it is even possible to extract that. I tried many different filters, but ...
5
votes
4answers
447 views

How can I return the color at a coordinate in an image?

I have an imported and cropped image: TestPicture = Import["filepath.jpg"]; TestPictureCropped = ImageCrop[TestPicture, Min[ImageDimensions[TestPicture]]]; How ...
3
votes
1answer
108 views

How do I access the binary matrix underlying an EdgeDetect output?

Applying EdgeDetect to an image generates a black and white edge-detected image, which I suspect corresponds to an underlying binary matrix. How can I access this ...
6
votes
4answers
273 views

How do I overlay corresponding values over each frame of an animation?

I recorded a phenomenon using video capturing (phen.avi, imported into Mathematica) and simultaneous measurement of some electrical properties of that phenomenon (a ...
1
vote
2answers
154 views

Image processing - How can I apply an operation to several images at once?

I imported pictures into Mathematica, and used names for them that follow the easy scheme "name" string joined with an integer, ranging from 14 to 20. Printing these images on screen works nicely: ...
4
votes
0answers
409 views

looking for a generalised Hough Transform function or a least a function to locate circles

I am looking for a generalised Hough Transform function or a least a function to locate circles (position of center and radius) in a image. There is the standard Hough line search function ...
0
votes
0answers
38 views

How to use an arbitrary closed region to extract an image region of interest [duplicate]

I am working on images and I need to be able to extract into a list all the image points that fall within a closed region, such as gotten from using "get coordinates". I can extract the points from ...
0
votes
1answer
317 views

How can I find lines of a certain angle(s)?

ImageLines implements the Hough transform, but how do I search for only lines within some threshold of a certain angle(s)?
4
votes
5answers
987 views

Get Coordinates in Image Processing

I'm new to Mathematica. I'm very impressed about it's abilities. It's very easy to achieve complex tasks. But I fail the simple ones. How can I get coordinates in image processing? I'd like to ...
11
votes
3answers
493 views

Rotate a grid, made up of lines, so that it aligns with the xy axes

While working on an answer for another problem I hit upon one of my own. I took the image given in that question and cleaned it up so that I could detect the grid lines: ...
23
votes
3answers
1k views

How to detect crosses and circles in 60x60 raster images?

I have hand-written 60 pixel times 60 pixel squares. I need to detect whether they are empty, x or circle. TextRecognize function fails. Is there some other function to process this kind of raster ...