Questions on the image processing capabilities implemented in Mathematica.

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19
votes
1answer
2k views

Finding the area, algebraic curve and jaggedness of an arbitrary shape

I start with a photograph of a shape (physically made by the flow of a liquid into another), of which I can extract the border, manually or using Mathematica's feature detect feature : Using the ...
12
votes
3answers
840 views

Image levels: how to alter 'exposure' of dark and light areas?

I was working with some less than ideal photographs, and wanted to adjust them before continuing. I wanted to raise the levels of the very dark areas and lower the levels of the very light areas. I ...
3
votes
2answers
933 views

video image recognition [closed]

Has anybody experience with video and image recognition? I've made a video of two teams playing soccer. Now I would like to translate each soccer-player to a (x,y) coordinate and follow them during ...
6
votes
3answers
266 views

Inconsistent image sizing with Grid and Row?

Can anyone explain why Row and Grid don't size the image correctly and consistently to 300 ...
4
votes
2answers
119 views

Share a method to patch the discontinuous line in a image

Similar to this post which I have posted before(How to patch fingerprint ridges),Its solution's level higher than my expectation.So cost my these days to research this.Now I'm glad to share my fruit ...
12
votes
2answers
1k views

Detecting an ellipse in a glaucoma photo

For glaucoma diagnosis it is common to determine a "cup to disk ratio" which compares the diameter of the optic disk (VDD) and optic cup (VCD). The optical disk is visible as a circular red feature (...
12
votes
3answers
4k views

Saving high-quality graphics through commands

Say I make and display a graph in a Mathematica notebook: graph = CompleteGraph[100] If I drag the corner of the graph to increase its size, and then save it to ...
11
votes
1answer
1k views

Implementing OCR without using TextRecognize

I am new to Mathematica and trying to figure out whether it is a good tool for algorithmic exploration. So I had the idea of implementing a simple OCR with Mathematica, just using standard algorithms....
6
votes
2answers
761 views

Fit an image within a Rectangle [] in Graphics

Based on the following Code (yet the white text in the image is added with PPT), I would like to have an image fit within one of the rectangle. For Example the image from there : http://...
6
votes
3answers
649 views

Opacity and overlapping multiple polygons

Let's say I have 100 polygons that are all different but most of them overlap. All I want to do is to draw/plot them in one single graphic with linearly adding gray values; i.e., a point with ...
11
votes
3answers
427 views

Best method to find variation in width along the image of a slit?

EDIT: Solutions by @Alexey Popkov and @Vitaliy Kaurov are very intuitive and both can be used to find a solution for the task. I have a slit of 15-18 microns by 1 mm projected with magnified 4X onto ...
4
votes
1answer
504 views

How to get better quality EPS graphics

Yesterday, I was doing any Tables of 15 graphs similar to the next example, to save .eps and use in latex. In the generation of the graphs Mathematica spends many time. Is possible to reduce this ...
4
votes
1answer
381 views

Butterworthfilter data filter

I am currently doing a signal analysis and filtering using Matlab. The filter I am using is Butterworthfilter model to filter scattered data (vector data). I am using Matlab as follows: ...
2
votes
2answers
352 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 = ...
67
votes
4answers
10k views

Programmatic approach to HDR photography with Mathematica image processing functions

The High dynamic range imaging (HDR or HDRI) direction in photography and image processing became very popular recently. Besides obvious photo art applications (see examples), there are many great ...
31
votes
3answers
2k views

xkcdConvert routines perform slower in Mathematica 9

I am experiencing some rather large performance decreases in Mathematica version 9.0 using the xkcd-styled plotting routines. I had used the xkcdConvert code ...
16
votes
2answers
1k views

How to automatically remove text from images?

I'd like to remove the text in the center of images automatically. To use Inpaint[], you need a mask, but I don't have one. So really the problem is: How to build ...
25
votes
3answers
2k views

Finding a function that fits the shape of an image

How can I find a function that fits the given shape of an image? Or instead extract a point set from the shape and then find an interpolating function fits the shape. An example image is attached.
29
votes
4answers
2k views

Clustering of space-time data

Below is an example of a gaze sequence I recorded during a 3 seconds display. That is, where the eye was at every millisecond. While we should have 3000 points, we are missing some due to blinking. ...
23
votes
3answers
2k views

Data fitting with Image processing feature detection

I have some 2D data that once plotted looks like the following ...
16
votes
6answers
2k 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, ...
15
votes
1answer
599 views

How to use 2D Fourier analysis to clean the noise in an image

I have some other method to do this.But I desire to know how to use Fourier analysis to realize it. I found a base post about Fourier-analysis to use in Image-Processing--Calculate the 2D Fourier ...
15
votes
2answers
2k views

How to convert an image to a graph and get the positions of the edges?

I am trying to convert an image to a graph. My image is already skeletonized and looks pretty much like this: What I need to do is identify all vertices and edges, and in particular get a list of ...
11
votes
4answers
3k 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 x-...
7
votes
2answers
456 views

Band Intensity Quantification

I would like to measure the density of my western blot band by measuring the area under the peak from this plot. More specifically, my image will have several lanes with a pattern of bands in each ...
22
votes
3answers
1k views

Detecting X or O in a small image

I am making a robot that plays Tic Tac Toe Currently, I have code that will parse the board and separate it into an array of 9 images, each space on the board. How can I detect if the image ...
13
votes
1answer
1k views

Enlarge an image and increase its resolution

An ongoing purely recreational project. I got my introduction to image processing with this Rotating perspective... question and had a lot of fun with it. Now I want to take it to the next step. ...
24
votes
3answers
2k views

How to find the center of a circular pattern?

I am writing an algorithm that finds the center of 500 x 500 pixels images coming from a live feed from a camera at 50 Hz. So it has to be quick! The images are images of an optical field which looks ...
21
votes
2answers
674 views

Convert binary voxel image to geometric region

I have a binary voxel image which described a contiguous region in space. Example: ...
19
votes
2answers
811 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 ...
17
votes
3answers
2k 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 ...
15
votes
2answers
587 views

Intersecting parabolas in an image

I have a friend who is a math teacher (like me) and while out cycling took this picture. The idea would be to create the equations of the quadratics that model the bridges and super-impose them on ...
13
votes
1answer
756 views

Ellipse counting from image

I have hundreds of images similar to this image: I'm looking to count the number of ellipses as well as their major and minor diameters. The ellipses are touching, hence, ...
12
votes
1answer
558 views

Precise cropping with ImageCrop

The built-in ImageCrop function "effectively removes borders from image whose pixel value distribution is almost uniform" (emphasis mine). I need an efficient ...
23
votes
3answers
1k views

Download xkcd Click and Drag comic

Inspired by the recent question about xkcd styled plots I started looking at xkcd again and I came across a comic titled Click and Drag. And if you do that, you start exploring a larger drawing. A ...
19
votes
3answers
3k views

Filtering pixels of a certain color

What is the best way to filter an image so that only the pixels close to a certain color are left? I've downloaded some satellite images from the web where a specific pixel color corresponds to a ...
8
votes
4answers
10k views

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

Imagine I have a set of data like the following: ...
3
votes
2answers
1k 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 ...
17
votes
2answers
853 views

Extracting angles from a simple picture

I'm not sure if this is even possible with Mathematica, but I want to extract the angles between all lines in this picture: It consists of $12$ lines, so I want a matrix with $144$ entries. I ...
6
votes
1answer
171 views

APIFunction on Images

Would someone example why my hello-world example is not working: ...
20
votes
3answers
2k views

Finding the centroid of a disk in an image

I got about 100 images of the sun and have to find the centre of the star in the images. I have binarized the images and used ComponentMeasurementsto find the ...
12
votes
1answer
1k views

Copying an image from the clipboard, modifying it and returning it to the clipboard

I have a Mathematica script to help me copy images from PDFs and then make the (presumably white or nearly white) background transparent. Typically, I am looking at the PDF in Adobe Acrobat and I ...
10
votes
1answer
275 views

How to patch fingerprint ridges

I get a fingerprint: But as you see,there are some place is discontinuous,such as: The question is how to patch the discontinuous line according its gradient?The only one thing that I can think ...
8
votes
6answers
300 views

Coloring an image with two Color schemes based on a Range

I would like to color an image generated from some data, using two color schemes based on two ranges of the data. This is my attempt: ...
11
votes
2answers
2k views

Overlapping accurately Images and Graphics (without loss of resolution)

Context In a previous post, I learned how to produce these kind of plots, which are of interest in astrophysics and geophysics. I am now interested in combining them. Attempt For this purpose, ...
10
votes
1answer
2k views

Construct 3D image from multiple 2D images

My goal: How to (1) construct 3D image for visualization. (2) how to write 3D array or image into binary raw file. Is there a way to accomplish this in Mathematica? Alternative_Answer for: (...
8
votes
1answer
615 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: ...
7
votes
1answer
703 views

Calculation of 2D FFT for an image

I am trying to obtain 2D FFT of an image. From the 2D FFT, I wish to calculate the amplitude of the FFT averaged over a circle vs the distance in pixels by varying the radius of the pixels which is ...
5
votes
1answer
236 views

Trace one point's coordinate values in sequentially images

I am a research student in a university. I think I need some help. I used a video camera to monitor the vibration of a plank. Then I should calculate the amplitude and frequency of the vibration ...
3
votes
1answer
1k 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 ...