Questions on the image processing capabilities implemented in Mathematica.

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40
votes
7answers
2k views

Character edge finding

The following line of code finds the edge of a character: ...
65
votes
3answers
6k views

Recovering data points from an image

Unfortunately, some data can only be obtained in picture form (Japanese publications anyone?). Since this cannot be worked with, it has to be converted to a dataset that can; I was wondering whether ...
37
votes
5answers
5k views

How can I extract data points from a black and white image?

Consider the following graph (source): Is there any way to extract the data points from this image in a semi-automatic way? I have seen, and tried the methods suggested in this question, but they ...
54
votes
1answer
4k views

Torn edge paper effect for images

In my answers to Plotting Error Bars on a Log Scale I used a so called "torn edge" effect from on one of the images. @SjoerdC.deVries commented: "BTW I liked the ripped-out look of your InputForm ...
29
votes
3answers
5k views

How to find circular objects in an image?

How could I use morphological processing to find circular objects in an image? More specifically, I need to detect road signs. I need to get the "80 speed limit" sign from this image:
74
votes
4answers
6k views

How to peel the labels from marmalade jars using Mathematica?

How can I detect and peel the label from the jar below (POV, cylinder radius, jar contents are all unknown) to get something like this, which is the original label before it was stuck on the jar? ...
34
votes
3answers
2k views

Identifying critical points/lines of 2/3D image/cubes

Upshot I am interested in identifying critical points of a 3D field/cubes (maxima, minima, tube-like and wall-like saddle points) and 2D field/image (maxima, minima, saddle points). I.e. the ...
26
votes
4answers
2k views

How to make a drop-shadow for Graphics3D objects

What's the best way to make a drop shadow for a 3D object? image = Graphics3D[Sphere[], Boxed -> False] I can get a blurry black outline of this: ...
23
votes
3answers
2k views

How to extrude a 3D image from a binary 2D image

I'm trying to extrude a nice 3D form from the 2D binary image below using the code posted, but I haven't had any luck in figuring out the error that's keeping ...
73
votes
8answers
13k views

How to make an inkblot?

How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.'s Rorschach demonstration): ...
43
votes
2answers
2k views

Detecting grid lines in a raster image

Motivation: Last October 7 there was a presidential election in Venezuela. Although the opposition saw an unprecedented increase in its votes, the government votes increased even more resulting in the ...
70
votes
11answers
6k views

Artistic image vectorization

The question is how can we use Mathematica to create vectorized versions of low-resolution images? The goal is to get an image suitable for quality printing at any resolution. Since "true" ...
47
votes
1answer
3k views

Measuring fractal dimension of natural objects from digital images

This is a useful topic. A college physics lab, medical diagnostics, urban growth, etc. - there is a lot of applications. On this site by Paul Bourke about Google Earth fractals we can get a high ...
7
votes
2answers
327 views

Using a given colour table with Image?

Context I would like to represent large images with a given colour table. Now, if I use Image ...
152
votes
2answers
57k 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) ...
26
votes
5answers
1k views

Create magnified call-out loupe effect on image

I'm trying to create a Mathematica Manipulate that generates a graphical call-out using a 'loupe'-style or magnifying glass enlarger - a possible solution is shown ...
38
votes
2answers
2k views

How can I add drop shadows and specular highlights to 2D graphics?

I thought I'd share some code in the form of a self-answered question, but other answers are of course welcome. Drop shadows are a familiar visual effect, giving the impression of a graphical element ...
41
votes
3answers
5k views

Image processing: Floor plan - detecting rooms' borders (area) and room names' texts

Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans. The ...
39
votes
3answers
2k views

Mollweide maps in Mathematica

Context In my field of research, many people use the following package: healpix (for Hierarchical Equal Area isoLatitude Pixelization) which has been ported to a few different languages (F90, C,C++, ...
19
votes
2answers
731 views

How to make a curve selectable from a scaned image and convert it to a list of coordinates

I have a scanned image (binary-ized): Is there any way to reduce one of these curved lines (full or dotted) to a series of its coordinates (e.g., sampling interval of 0.01 on x-axis)? I've read ...
17
votes
1answer
1k views

How to extract metadata from an image of a business card?

I'm trying to digitize some documents, and I came across a very cool app called camscanner app which performs parallax transform and ocr very nicely, now I'm implementing it in mathematica... Given ...
30
votes
1answer
1k views

May the Fourth be with you

Happy Star Wars day. I was playing around with the image manipulation functions in Mathematica in an attempt to recreate the Star Wars crawl. There's an HTML/CSS implementation which is in my ...
8
votes
4answers
7k views

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

Imagine I have a set of data like the following: ...
16
votes
2answers
1k views

How to combine images with the same dimensions in a grid?

I have the following images, both 480 x 270 pixels: I'd like to stitch them side by side in a 960 x 270 pixel image like so (scaled down): So far, I've been using ...
-2
votes
1answer
4k 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.
4
votes
1answer
319 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 ...
2
votes
1answer
224 views

How to highlight image edge with spline/bezier when mouse moved over?

It is known that EdgeDetect can find image edges in an image. Suppose the image edges consists of sets of lines. Can the detected edge line near the mouse pointer be highlighted as spline/bezier when ...
1
vote
2answers
271 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 = ...
167
votes
2answers
38k views

Help find a bright object on Mars!

In today's news, scientists found a bright object on one of Curiosity's photos (it's near the bottom of the picture below). It's a bit tricky to find - I actually spent quite some time staring at the ...
51
votes
3answers
24k views

How to create a new “person curve”?

Wolfram|Alpha has a whole collection┬╣ of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica ...
35
votes
1answer
1k 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 ...
47
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 ...
31
votes
1answer
3k views

The correct way to linearize colorspace before resizing, blurring etc

There was an interesting discussion on MathGroups dealing with the fact that image-processing functions in Mathematica (and many other software, including Adobe Photoshop) work with RGB, Grayscale ...
44
votes
3answers
2k views

Changing color of an object in an image

Consider the following image: How can I change all red colors in this image into (for example) blue.
28
votes
5answers
1k views

Voronoi diagrams for generators other than points

Any suggestions how to determine Voronoi diagram for sites other than points, as e.g. in the picture below? Input is a raster image.
16
votes
2answers
4k views

How can I detect a rectangular region of interest in a picture?

Here is a downsampled input image I converted to greyscale. To select the rectangular region of interest we first preform preprocessing: ...
25
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 ...
8
votes
3answers
978 views

Line Intensity Profile From Image

I can get line profiles from images using imagej but it would be nice to be able to do this in my mathematica notebooks. I found this http://library.wolfram.com/examples/intensityprofiles/ after ...
22
votes
4answers
3k 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 ...
16
votes
1answer
465 views

Speed up adding Poisson noise to an image

I'm simulating some images corrupted with Poisson noise, but I'm encountering a few problems with performance. According to the documentation on ImageEffect, one ...
12
votes
1answer
619 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, ...
11
votes
3answers
3k views

Composing an image with a plot

I'm trying to illustrate the solutions to a textbook problem dealing with quadratic functions. This will involve plotting a quadratic and overlaying the plot and the image. Here is the textbook ...
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
750 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 ...
10
votes
1answer
803 views

Count Elements in Image

I have the following image: img1 I'm trying to count al these colored cells and draw a circle around them. I really don't now how I can use SelectComponents for ...
8
votes
4answers
710 views

Image correlation

I have two images from motor scan, Image1 is shifted by MxN pixels from Image2. How can I find the shift between Image1 and Image2 ? Image -1 Image -2 If we compare the shift between the images ...
3
votes
2answers
644 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 ...
11
votes
3answers
3k 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 ...
10
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 ...
5
votes
4answers
183 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 colorschemes based on two ranges of the data. This is my attempt. ...