Questions on the image processing capabilities implemented in Mathematica.

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5
votes
3answers
868 views

Parameters for the CIE XYZ Color Space in Mathematica

In Mathematica, producing a color based on its RGB parameters is easy; one can use (for example) ...
5
votes
1answer
134 views

Scaling an image with “Drawing Tools” primitives on it

Imagine I doodle with the "Drawing tools" pen, or place lines on an image after importing it. Now say I want to scale this image by some constant factor $C$ while maintaining the same aspect ratio. ...
2
votes
2answers
347 views

Introduction of bias during brightness and contrast manipulation of an image

Quoting from Nature magazine's "Image integrity" guidelines: Processing (such as changing brightness and contrast) is appropriate only when it is applied equally across the entire image and is ...
6
votes
1answer
263 views

Digital Elevation Maps (DEM) are Warped yet ReliefPlot renders as a rectangle - how do i join?

I downloaded several USGS Digital Elevation Maps (DEM files) corresponding to 12 adjacent areas. Each file Imports[] into Mathematica and I can render the individual ...
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 ...
5
votes
1answer
534 views

How do I put an image on the complex plane?

I watched this video and became interested in transforming an image. But I have no good idea on how to embed an image in the complex plane using Mathematica. I have a method that seems to work, but ...
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: ...
3
votes
1answer
229 views

Weird resampling when I try to export an Image

Mathematica language newbie here. I wrote the following code to quantize an image: ...
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.
12
votes
1answer
423 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 ...
4
votes
1answer
729 views

Extract data from plots in papers including error bars

I would like to know how to extract data from plots in a paper and, also, how to do that in a way that include error bars. I know there are specific softwares to do that, e.g. Plot Digitizer, which ...
1
vote
2answers
237 views

Number of edges to each polygon of a graph constructed from an image

I have an image which looks like from How to convert an image to a graph and get the positions of the edges? which by using MorphologicalGraph becomes a graph ...
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 ...
4
votes
1answer
175 views

How does DistanceFunction work with images in ClusteringComponents?

Does anyone know the syntax to DistanceFunction? I am trying to define my own function to use with ClusteringComponents; e.g., ...
3
votes
1answer
302 views

Filter bright dots from the gradient of the image

I am wondering how to filter out bright dots in the picture, which are caused by background noise. I have used gradient filter in mathematica but it doesn't help. Is there anyway, that I can plot ...
3
votes
2answers
222 views

How to remove border points from InputForm?

I have this code, and it generates the below ListStreamPlot. The second graph is the ListStreamPlot overlaid with the points ...
5
votes
1answer
442 views

How can I find a particular character in an image that has many similar Chinese characters? [duplicate]

The Chinese characters "竟" and "竞" are very similar in their appearance. I am trying to find "竟" in the following picture. I tried use TextRecognize but it ...
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 ...
15
votes
3answers
1k views

How to remove constant background from an image?

I'm not sure how to remove the paper background from this logo with v9. This is really not the same as this question, but I think similar methods apply.
3
votes
3answers
376 views

How to find Image Size of a control object?

I want to find the ImageSize or at least dimensions of any control object irrespective of it being an image or an any other control such as ...
3
votes
2answers
623 views

HSB -> HSL Converter

Starting from an image I would like to apply a custom filter to an image. I have thought and implemented this filter in HSL space and it goes like this : Boost the saturation of the pixels that ...
51
votes
3answers
24k views

How to create a 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 ...
0
votes
2answers
165 views

Automating the “Get Indices” right click function

Is there a way to do this? What I am trying to do is allow a user to take a lineout averaged over the rows of a user defined ROI (Region of Interest) of an image. I have the bit of code that allows ...
31
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 ...
29
votes
2answers
930 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). ...
8
votes
3answers
409 views

Radon function result's repeatability

Bug introduced in 9.0.0 and fixed in 9.0.1 I want to get a Hough transform of some edged image. When I compare the same transformation on the same image I got different results. ...
10
votes
1answer
3k views

Image Processing: Finding Orientation and Position of Symmetry Axes

Background I'm currently toying with Principles of Design by Charlotte Jirousek in order to learn some basics of image processing. As main principals she suggests Balance, Proportion, Rhythm, ...
17
votes
6answers
1k views

How do I make an image “nearly” black and white?

Using the following code, I downloaded an image from the web and adjusted the image to obtain the "negation" of the image: ...
12
votes
2answers
271 views

Why does DominantColors keep shuffling the order of the results?

This graphic is produced by running DominantColors (new in Mathematica 9) with different values, using the Lena image as the source: Each row is a list of the ...
33
votes
1answer
2k 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 ...
6
votes
2answers
2k views

Deformed style when exporting eps files

I want to export a plot into an eps file. Below I present a sample plot code in order to demonstrate the two issues that appear. (1). LabelStyle: When I use ...
4
votes
2answers
310 views

How can I superimpose points or disks on an image at specified coordinates?

I have a TIFF image of 640 x 640 pixels, over which I would like to plot a list of points or disks of small radius. I have been testing different alternatives and I found ImageCompose command. ...
12
votes
2answers
2k views

Push-pin Art – Convert image to R-Y-B-W-Blk color space

After seeing an example of what is called “Push-pin Art”, I assumed that Mathematica would be able to handle the kind of image processing required to convert an image to this format. I am not well ...
9
votes
2answers
967 views

How to transform a 3D image by an affine transformation matrix

I have a question concerning Image Processing: I have a stack of images, which I can compose to a 3D image using Image3D. Additionally I have a 4x4 affine transformation matrix. I would like to ...
2
votes
2answers
250 views

Take part of image under locator

How to create Manipulator with Locator to take part of an image?
27
votes
2answers
675 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 ...
10
votes
1answer
802 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 ...
5
votes
2answers
478 views

What is ImageDistance measuring?

What quantity is ImageDistance measuring, and what do the numbers mean? I found the ImageDistance command in Mathematica 9, but ...
10
votes
2answers
261 views

How to extract a specific element from EXIF photographic metadata?

It's now possible to import photographs into Mathematica and import the EXIF data at the same time: i = Import["ExampleData/coneflower.jpg", "ImageWithExif"] ...
2
votes
1answer
591 views

HOG descriptor for image processing

I did not find in Mathematica a function for Histogram of Oriented Gradients (HOG) descriptors. Is there any similar function? Do you have an implementation you are willing to share?
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 ...
21
votes
2answers
771 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 ...
2
votes
3answers
709 views

Color mixing or blend

Color mixing seems not only one type. Here is RGB_color_model I wrote this one: ...
12
votes
2answers
751 views

Finding the Centroid of the grid

Im trying to automate the processing of my shooting targets to measure my performance in the range. I was able to process the shots, but I still have to select the center of the target by the use of ...
5
votes
1answer
444 views

Accessing the graph Thinning produces without losing all the edges' lengths/slopes

This is a follow up to the OCR question I had earlier. What I want to do is to use Thinning to create "skeletons" of images of characters and then compare their shapes, utilizing such properties ...
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 ...
0
votes
0answers
98 views

How to make 3d solid volume from set of images [duplicate]

Possible Duplicate: How to show solid bodies using volumetric rendering? I have a set of images, and I want to construct a z-stack, then reconstruct it to a 3d volume. My previous ...
10
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, ...
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++, ...
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 ...