Questions on the image processing capabilities implemented in Mathematica.

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157
votes
2answers
37k 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 ...
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) ...
67
votes
4answers
5k 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? ...
62
votes
11answers
4k 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" ...
51
votes
3answers
5k 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 ...
49
votes
3answers
4k 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 ...
47
votes
5answers
8k views

How to create hedcut style images?

Yesterday the hedcut style was brought up in chat. How can we create a hedcut-like style automatically in Mathematica, using a photograph as a starting point? I am looking to create a similar ...
47
votes
1answer
3k 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 ...
43
votes
3answers
19k views

How to create new “person curve”?

Wolfram|Alpha has a whole collection¹ of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica ...
41
votes
1answer
2k 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 ...
40
votes
3answers
1k 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.
40
votes
2answers
1k 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 ...
37
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 ...
36
votes
2answers
940 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 ...
34
votes
3answers
3k 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 ...
33
votes
4answers
2k views

Remove image background of headshot in Mathematica?

For example, using ExampleData[{"TestImage", "Girl2"}]: what's a general way to make the background transparent? I've tried various combinations of ...
32
votes
1answer
937 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 ...
31
votes
5answers
4k 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 ...
31
votes
2answers
960 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 ...
31
votes
2answers
6k views

Image Shadow Removal in Mathematica

The task is: Image shadow removal is an important topic in image processing. If you feel curious about it, you may take a look here, or just google for it image shadow removal There are also a ...
30
votes
3answers
1k 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 ...
27
votes
5answers
2k views

Identifying critical points 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
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 ...
26
votes
5answers
940 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.
26
votes
1answer
971 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 ...
25
votes
2answers
581 views

Counting radial ridges on an image

After happily using the v9 image assistant to crop elliptically an image, and then the drawing tools to put a white disk in the middle, I turned this image: into the following one: that can be ...
24
votes
3answers
3k 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:
24
votes
2answers
804 views

Cleaning mildew from old documents using Mathematica (Image processing)

While visiting family over the holiday period, I managed to have some good mother-daughter bonding over how far back I’ve managed to trace the family tree (Mom is in her 80s and doesn’t do computers). ...
24
votes
1answer
1k views

FindFaces: how to improve the results of the face recognition feature

In Mathematica 9, the FindFaces command offers an easy way to detect faces. In some experiments, I've been getting reasonable results, but I'd like to know if there ...
23
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
4answers
1k 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
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 ...
23
votes
3answers
1k 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 ...
22
votes
3answers
1k 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 ...
21
votes
2answers
948 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 ...
21
votes
1answer
1k views

Is there a way to convert an image into a Graph?

I'm trying to convert an image with several overlapping dots into a Graph. The goal is to be able to derive the Kirchhoff matrix for the randomly created "network ...
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 ...
20
votes
2answers
546 views

Is there a Mathematica barcode reader?

Is there a Mathematica barcode image reader (much like TextRecognize) that allows the user to enter an image of a barcode and then read it to get an output string?
20
votes
2answers
531 views

How to retrieve the parameters calculated and used by ImageAdjust?

When ImageAdjust is called with an image, i.e. with one parameter, it returns an automatically adjusted Image. I would like to ...
18
votes
4answers
389 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 ...
18
votes
3answers
2k views

Data fitting with Image processing feature detection

I have some 2D data that once plotted looks like the following ...
18
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 ...
18
votes
1answer
1k views

Using ImageCapture to access a USB webcam in linux

Is it possible to access a USB webcam through Mathmatica on Linux? When I run ImageCapture[] I get the following output ...
18
votes
2answers
1k 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 ...
18
votes
2answers
447 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 ...
18
votes
1answer
922 views

Rotating perspective of an image in the z axis

A purely recreational question, but one I hoped the community would find interesting enough to suggest a way to approach it. Let me preface this question with the admission that I have done nothing ...
17
votes
4answers
1k views

How to create effect like Van Gogh's stroke brush?

I need to apply Van Gogh's stroke brush effect to a random image Take the following image as an example: Thank you so much if you could help!
17
votes
2answers
1k views

How can I create a glass distortion effect in an image?

I'd like to overlay a glass jar onto an image with realistic light bending. Can anyone think of a way to automate this effect (perhaps this can be done with the raytracing package rayica)?
17
votes
3answers
1k 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 ...
17
votes
1answer
358 views

Color scheme used by Colorize?

The Colorize function is often used to display the results produced by MorphologicalComponents: ...