Questions on the image processing capabilities implemented in Mathematica.

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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 ...
3
votes
1answer
131 views

Resampling when using image as Texture

How to get sharp pixel boundaries with Texture? I'd like to have only black/white in the example below, no gray. ...
2
votes
3answers
233 views

Using ImageTransformation[] with a lookup table

I need to transform images by ImageTransformation in a time critical application. Therefore I precalculate a lookup table lut of ...
0
votes
1answer
125 views

TextRecognize with crosses, circles and spaces results into oddities, why?

I am investigating this answer here about detecting crosses and circles with TextRecognize. I tried to solve this problem here by directly using the builtin command TextRecognize but it does not work ...
32
votes
1answer
846 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 ...
14
votes
6answers
1k 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, ...
0
votes
1answer
105 views

Outputting a set of graphics 3D objects with positions defined by one array and colors by another? [duplicate]

I have a set of 2- or 3-space coordinates in an array, $(v_1,...,v_N)$, and an array of RGB color values (outputs from ImageValue[]) for each coordinate, $(c_1,...,c_N)$. How can I output a ...
3
votes
1answer
540 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 ...
5
votes
4answers
426 views

How can I return the color at a coordinate in an image?

I have an imported and cropped image: TestPicture = Import["filepath.jpg"]; TestPictureCropped = ImageCrop[TestPicture, Min[ImageDimensions[TestPicture]]]; How ...
3
votes
1answer
98 views

How do I access the binary matrix underlying an EdgeDetect output?

Applying EdgeDetect to an image generates a black and white edge-detected image, which I suspect corresponds to an underlying binary matrix. How can I access this ...
6
votes
4answers
249 views

How do I overlay corresponding values over each frame of an animation?

I recorded a phenomenon using video capturing (phen.avi, imported into Mathematica) and simultaneous measurement of some electrical properties of that phenomenon (a ...
1
vote
2answers
142 views

Image processing - How can I apply an operation to several images at once?

I imported pictures into Mathematica, and used names for them that follow the easy scheme "name" string joined with an integer, ranging from 14 to 20. Printing these images on screen works nicely: ...
4
votes
0answers
350 views

looking for a generalised Hough Transform function or a least a function to locate circles

I am looking for a generalised Hough Transform function or a least a function to locate circles (position of center and radius) in a image. There is the standard Hough line search function ...
0
votes
0answers
37 views

How to use an arbitrary closed region to extract an image region of interest [duplicate]

I am working on images and I need to be able to extract into a list all the image points that fall within a closed region, such as gotten from using "get coordinates". I can extract the points from ...
0
votes
1answer
292 views

How can I find lines of a certain angle(s)?

ImageLines implements the Hough transform, but how do I search for only lines within some threshold of a certain angle(s)?
4
votes
5answers
862 views

Get Coordinates in Image Processing

I'm new to Mathematica. I'm very impressed about it's abilities. It's very easy to achieve complex tasks. But I fail the simple ones. How can I get coordinates in image processing? I'd like to ...
11
votes
3answers
431 views

Rotate a grid, made up of lines, so that it aligns with the xy axes

While working on an answer for another problem I hit upon one of my own. I took the image given in that question and cleaned it up so that I could detect the grid lines: ...