Questions on the image processing capabilities implemented in Mathematica.

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37
votes
2answers
985 views

Reconstruct text pages cut by shredder

Q1: I have a page of printed text file, but it was cut by a paper shredder (from top to bottom). You can download all the paper fragment here. There are some examples of them. How can I reconstruct ...
7
votes
1answer
267 views

Is it possible to construct a topological map of road network of Bangalore?

I saw this example wherein the CityData gives the map of a city. But this is available for a relatively small set of curated regions. Is it possible to extract ...
20
votes
4answers
436 views

Running out of memory when partitioning an image with ImagePartition

I have an Image3D object of image type "Bit16" with the dimensions 1472 x 1472 x 1472 that I would like to split into small image cubes of dimension 64 x 64 x 64 ...
9
votes
1answer
274 views

Deconvolution of Image3D object using ImageDeconvolve

I am trying to get the ImageDeconvolve function to work with Image3D objects. In the documentation of ImageDeconvolve it says: ...
4
votes
0answers
636 views

computation of gradient vector field in 3D using GradientOrientationFilter

I want to compute a 3D gradient vector field of an Image3D object using the built-in GradientOrientationFilter function in Mathematica. From the documentation I ...
10
votes
2answers
316 views

How could I use Mathematica to remove finger tips that appear in images?

I used my photo camera to "scan" a heavy dictionary. I tried to have flat images by pressing the margins of the pages with my fingers. The color of the background is (normally) black and my fingers ...
46
votes
2answers
2k views

Image segmentation and object separation in 3D using Mathematica

I currently work on an image segmentation scenario to detect cell nuclei in 3D using Mathematica. The data I have are image stacks in the TIFF file format. I would like to keep the sequence of image ...
3
votes
1answer
326 views

Generating a graph object where vertices are pixel coordinates and edges represent two pixels being in the same Moore neighborhood

I have a list of integer pixel positions, pts, and I wish to create one or more graph objects where vertices at these pixel positions share an edge if they are ...
1
vote
1answer
153 views

Generating a list of contour pixels for a morphological component

I have a set of pixilated shapes, and after transforming each shape into a morphological component, I want to be able to return the coordinates for pixels that lie on the contour of the shape. More ...
2
votes
2answers
258 views

Is there a way to parallelize the convolution component of EdgeDetect?

Provided an image like - test = Import["http://upload.wikimedia.org/wikipedia/commons/d/d5/Sunflowers.jpg"] We can run ...
3
votes
0answers
289 views

How can I create jpeg images of a given file size?

Cross-posted at Wolfram Community I would like to have a function makeJPG[megabytes_] that generates random jpg images of given file sizes with itf filesize (in megabytes) watermarked on the image ...
1
vote
1answer
175 views

Efficiently determining if a morphological component overlaps a polygon with vertices at real number coordinates

I have a list of morphological components $m$, a set of vertices for a polytope $P$ (at real number coordinates), and I'd like to be able to calculate a list of morphological components $m'$ that ...
13
votes
1answer
531 views

How to identify chemical substance from tattoo?

A friend of mine made a tattoo on his chest of some chemical substance formula. He challenged us to identify which substance is that. I thought that perhaps a combination of: Mathematica image ...
2
votes
1answer
133 views

Selecting for morphological components that do not border the edges of an image?

Is there an easy way to select for morphological components which do not border/touch the edges of an image? Taking this doodle as an example: We'd want to only select morphological components ...
12
votes
2answers
861 views

How can I efficiently “remap” an image?

Many image processing libraries like OpenCV, Intel Performance Primitives or Octave have a useful function called "remap", that takes an image, an array with X coordinates and an array with Y ...
5
votes
1answer
435 views

Failing to import an .eps file

I have an .eps file which was created using GLE. There is nothing wrong with the file, GS View can read it correctly. However, when I use Mathematica to read it using ...
1
vote
2answers
183 views

Image's pixels GPU colour classes splitting

How can I split in color classes, the pixels of an image that I load in Mathematica? I would an output like this: ...
1
vote
0answers
47 views

How can I manipulate a circular part of an image? [duplicate]

I want to a specific part of an image, while leaving the rest of the image unchanged: The part should be circular en the center and radius of the circle should be easily adjustable. So far I can only ...
13
votes
3answers
506 views

Detecting and correcting gradational brightness variations in a grayscale image

I am trying to quantify the proportions of various components in a greyscale image (backscattered electron image of a polished rock sample). Here is the original image: ...
9
votes
1answer
888 views

Measure length and diameter of objects in an image

I am new to Mathematica, and I am trying measure length and diameter of rectangular objects in an image. I wanted to fit rectangles in the objects, and then get the values. Can I do that with ...
0
votes
0answers
385 views

Metric Parameters such as Pratt Figure of Merit (Pratt-FOM) for Edge Detection

I have developed a new algorithm in Mathematica v9.0 for the Edge Detection and want to compare it with the existing Roberts, Sobel, Prewitt etc, operators in the presence of Noise. I have evaluated ...
3
votes
2answers
566 views

Generating x,y coordinates for an edge detection

I'd like to be able to process a number of graphics that have edge contours and output a list of $x$, $y$ coordinates to be used for generating a spline in another program, or in Mathematica, to make ...
1
vote
1answer
192 views

in search for mathematica function similar to imagesc in matlab

Simple question: Is there any built in function for images that acts similar to imagesc in matlab, i.e. take grayscale image scale it to use full [0,1] range and then use some kind of colorgradient to ...
2
votes
0answers
249 views

Understanding “IntensityData” coordinates

Update - Playing around a bit, is it true that we need to process the list of "IntensityData" values $r$ as follows: r = Partition[r,k]; r = Transpose@r; And ...
15
votes
4answers
864 views

Measure perimeter of black edge in Mathematica

I have a pattern like the one below. How could I measure the total length of the perimeter of the black/white edge? This would give me a measure of spatial frequency. Any tips would be great! Thanks! ...
2
votes
1answer
152 views

Understanding the computation of IntensityCentroid?

If I have an image img, and I ask ComponentMeasurements to return "IntensityValues" for the ...
-2
votes
1answer
412 views

Peak Signal to Noise Ratio of Images

I am filtering a blurred image, and want to evaluate the performance of Peak Signal to Noise Ratio (PSNR) in Mathematica version 9.0. But I am facing the problem of evaluating the PSNR. Could anyone ...
4
votes
4answers
611 views

Identifying and counting closely spaced particles

Following in the footsteps of this blog post: http://blog.wolfram.com/2011/09/09/building-a-microscopy-application-in-mathematica/, I took a microscope picture of some particles on a surface, and ...
-4
votes
2answers
335 views

Image Processing Mag and Phase Spectrum of Sobel, Roberts Mask [closed]

How to find the Magnitude and Phase Spectrum of Sobel, Roberts etc. etc. Mask of Image Processing using MATHEMATICA 9.0 platform....
5
votes
1answer
242 views

Cropping an image to a minimum bounding box for a set of points

Imagine a define a pointlist inside of an image: Provided a pointlist for the set of red dots around the toy horse, is there a way for me to automatically crop to a minimum bounding box for this ...
2
votes
3answers
302 views

Defining and isolating a region of an image internal to a bounding curve

I was recently looking over this very nice question by March Ho: Counting elements which are inside another element on a different colour channel There are often times where I find myself wanting to ...
1
vote
1answer
160 views

Can I use SelectComponents with measurements that take into account the value of underlying pixels?

Normally, we can ask for the mean, median, etc. underlying pixel values for morphological components with the command: ...
1
vote
1answer
156 views

How can I use SelectComponents to select for components that have a pixel within a certain RGB range within their convex hull?

I calculate a set of morphological components: Components = MorphologicalComponents[Binarize[image,0.1]]; We can now use SelectComponents to filter for ...
8
votes
1answer
364 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
203 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
240 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
119 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
142 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
399 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
215 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
347 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
203 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 = ...
-4
votes
1answer
3k 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
252 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
366 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
273 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: ...
12
votes
1answer
262 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
120 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
222 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
5k views

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

Imagine I have a set of data like the following: ...