# Tagged Questions

Questions on the image processing capabilities implemented in Mathematica.

556 views

### Remove country flags that match a certain image pattern

I wanted to create the flag you create when you average over all the flags of the world, for this little post: medium ...
69 views

### Detecting and measuring an ellipse in a glaucoma photo? [duplicate]

I've tried the solutions given in How to find a circular object in the image glaucoma? to detect the ellipse, but the detection results are not quite what I wanted. In glaucoma we have a cup to disk ...
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 ...
59 views

### Converting x,y pairs to an image: alternative to Histogram3D for sparse data?

I have a list of {x, y} integer pairs representing single events in pixel coordinates in the {x, y} plane, with occasional ...
152 views

### How to find analytical expresion for data from image

I need to find an analytical expression for the data collected from an image. I found a relevant topic on how to extract the data in here. But there are some differences in my question. I have this ...
58 views

### Creating rectangles from “ImageCorners” output

I want to create multiple rectangle areas from this image where the rectangle would be defined by the points on the edges of the outer most squares - dont mind the inner ones. In the end there ...
144 views

### Calculating consumed internet data from bitmap of chart

My internet connection has a speed drawn up by the y axes has a scale as KB per second. and the x axes is time elapsed. if the x axes be from 0 to 40 minutes how can I calculate total consumed ...
66 views

### Scan over array of images

I would like to take in an array of images as input, and then call the ColorSeparate function on each of them, and retrieve this as output. So far I have the following : ...
68 views

### How to determine the value of an angle starting from an image? [duplicate]

I have two lines drawn with Mathematica, how do I calculate the angle between these two lines to have the numeric value of that angle? Thank you
238 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 ...
21 views

### How to get an image when having indices of pixels [duplicate]

I am doing a perspective projection of a list of voxel V={v1,v2,v3,...,vn} using the perspective projection matrix 3*4 to get the indices of each pixel pi=(xi,yi). pi=P*vi Once I get the indices, I ...
230 views

### Creating a colour variation effect of the Northern Lights

As is well known (see https://www.youtube.com/watch?v=fVsONlc3OUY ), the Northern Lights or Auroral displays appear as variations of several colours (generally pale green and pink). Is there a ...
83 views

### Rotating an image if the height is larger than width?

I would like to rotate an image if and only if, the aspect ratio of the image is > 1, else just print the original picture and afterwards use the data. My problem is that Mathematica writes ...
151 views

### Image transformation to break up connected components

I have a picture of a bunch of sphere, and I want to calculate the centroid of each sphere on the plane and generate the Voronoi diagram for it. But (1) In the picture the sphere are contacting each ...
572 views

### Convert binary voxel image to geometric region

I have a binary voxel image which described a contiguous region in space. Example: ...
171 views

### PixelValues along a straight Line [duplicate]

UPDATE to the question I have reformulated the question in order to make it distinct from the one suggested as a duplicate: "Line Intensity Profile From Image." The key difference is that I'm ...
81 views

### Tracking movement via ImageFeatureTracking doesn't work

I have a series of 37 b/w microscopy photos. The whole sample shifts slightly (by ~10 pixels) from photo to photo (systematic error). See an example photo here and download two photos pos4_0.dat and ...
155 views

### Circular crop: extract non rectangular parts of an image

I want to extract a part of an image. For example, let's start with something like the following image: I would like to apply some image processing to get this result: I have tried to ...
197 views

### How can I delineate the outline of a complex shape?

I have a picture of a lake as follows: And I want to delineate the outline of the lake. I binarized the picture and obtained img: ...
38 views

### Minimum bounding rectangle of point set of image data + relative position

I have an image and a subset of points for which I want to get the minimum bounding rectangle (MBR), along with its relative position in the source image (so I can edit it somehow then restitch it ...
41 views

### In a list of Disk, how to efficiently delete Disk which are close to other Disk? [duplicate]

I want to draw pictrue like this: My code is: ...
96 views

### How to use the ButterworthFilterModel to processing image

In the book of "Digital_Image_Processing_3rd" point out this: the 4.57a,4.57b,4.57c is like follow: So I do it according to the direction to: ...
449 views

### How to create a 3D model based on MRI cross-sections?

Recently, I stumbled upon the following surreal MRI-scan of broccoli: and ever since the moment that I saw this I've been wondering whether it is possible to recreate the broccoli based on ...
193 views

### How to convert the binarize-picture to a Region

The Region of Mathematica is nice,and is the new conception of version 10.0.I can convenient get ...
978 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 ...
69 views

### Fill a Circle in an Image

Let's suppose I have something like this (the image resulting from this): ColorNegate[Rasterize[Graphics[Circle[{100, 100}, 50]]]] Now, what I want to do is fill ...
242 views

### Can I get the curvature at any point of a random curve?

Random curve like the above, for example. The data source is an image file. I don't have an expression. I want to start by curve fitting and then compute curvature. Is it possible?
595 views

### Can I OCR Mathematica code on an image?

There's no doubt that one should always post the Mathematica code text rather than its screenshot when asking questions in this site, but every time I saw someone posting a screenshot, I can't help ...
190 views

### Challenge: deblurring images [duplicate]

My friend came back from holidays, where he took lots of pictures. Unfortunately, the camera was set on manual focus and most pictures are blurry. It got me thinking that mathematica showed how to ...
119 views

### How to count the grid in the picture

I want to count how many grids in colunm and row,I know the answer is 38*11,But how can I use mma to count it?It confusion me ...
145 views

### Detect buildings in cadastral map as polygons

I have this topological cadastral map, and others: It can be imported into Mathematica using img = Import["http://i.stack.imgur.com/3udXJ.jpg"] I want to ...
73 views

### How to ImageIdentify multiple objects in a single image?

Suppose an image has multiple objects: ImageIdentify only finds the banana: ...
87 views

### Optimization of a voxel projection function

I implemented a function to check if a voxel (3D pixel) is well projected on the space of a image (black and white silhouette) through a perspective camera. The function does the work but It need more ...
101 views

### HighlightImage speed?

I am doing a study into image processing and motion detection. I am using various filters (ImageDifference, HighpassFilter, ...
236 views

### How to speed up PDF export in Mathematica 10

Based on this question: - Version 7 print environment - I set up two 10 page test documents in version 7.0.1 and version 10.1. The version 7 document exported to PDF in 4.18 seconds whereas the ...
493 views

### Angle between two areas of an image of a 2D FFT

I'm trying to obtain the angle between the red line and the area surrounded by the red circle, related to the middle of the image. Usually the area surrounded by the red circle is lighter than the ...
105 views

### Log transformation (in dimensions) of an image

Is there an easy way to do a log-transformation of an image? I'm not taking about the colours, but the geometry. The difficulty is to extrapolate pixels and round-offs. For example, an white image ...
92 views

### Rotate imported images which are inset into a Graphics container and then overlapped?

The methods given as answers to this question do not seem to work here. I suspect it is because of my use of Inset function. Consider two .png images hand1 and ...
169 views

### Image Processing: Car front detection

Background Image processing can be applied to car license plate detection problems see Wikipedia, segmenting numbers, belisarius's old answer. Also, on this site once can use some techniques ...
126 views

### Strategy to build efficiently an image using parts of many images

I have about 1000 images of 1000px $\times$ 1000px and a list which contains the coordinates of the pixels to select, for each of the 1000 images. Each pixel is used once, so the final image is a full ...
291 views

### How can this resampling code be made faster?

Suppose I have a matrix: sbt = RandomInteger[{0, 2^16 - 1}, {5202, 3465}]; It represents an image and I would like to do "pixel binning" on it, where I take ...
213 views

### Adjacency matrix from image file of plane map

I have image files (PNG format) of plane maps of regions delimited by black borders I would like Mathematica to compute the associated adjacency matrix for the contiguous regions in these maps. ...
42 views

### How to avoid “Quit[]” to execute notebook multiple times [duplicate]

I am using a program to binarize several images and then adding all the images together using "ImageAdd" to get one image. This image is required for further analysis of the images. The program ...
78 views

### Remove color artifacts in overlay of several Graphics objects?

I am trying to create an animation with a graphic of an arm that can bend at the elbow. For this purpose I created the following two images: hand1 and hand2. I load the images with ...
80 views

A recent thread raised several concerns regarding the Documentation page for ImageAdjust. The first issue is related to the first statement under the ...
69 views

### Detecting discontinuities in derivatives in images

Considering an grey-scale image as a function $z=f(x,y)$. (Specifically, I'm interested in $f=h*h*...*h$, where $h$ is the indicator function of a regular hexagon.) I am interested in finding places ...
620 views

### How to detect loops in a vector field?

Given a vector field and I'd like to detect if there are streamlines in closed patterns. For example, if the input is a vector field like this: ...
344 views

### Coloured image transformation in pointillism

I would like to transform an image (a photo for example) into a set of single colour circles with fixed but adjustable diameter (bigger than the pixel size), into a kind of pointillism. The number of ...