Questions on the image processing capabilities implemented in Mathematica.
42
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 ...
40
votes
3answers
2k 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 ...
57
votes
4answers
4k 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
2answers
832 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 ...
18
votes
3answers
687 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:
...
54
votes
8answers
2k 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" ...
25
votes
5answers
2k 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 ...
13
votes
2answers
535 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 ...
13
votes
2answers
990 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:
17
votes
3answers
695 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 ...
11
votes
3answers
424 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 ...
133
votes
2answers
35k 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 ...
23
votes
1answer
422 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 ...
32
votes
3answers
850 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.
24
votes
5answers
708 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 ...
25
votes
3answers
901 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 ...
20
votes
3answers
760 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 ...
12
votes
4answers
499 views
What is the fastest way to locate an image inside a larger image?
let b =
let c =
How to do:
find[c,b]
that returns the bounding box of c in b?
...
16
votes
3answers
840 views
Data fitting with Image processing feature detection
I have some 2D data that once plotted looks like the following
...
8
votes
1answer
754 views
Construct 3D image from multiple 2D images
My goal: How to (1) construct 3D image for visualization.
(2) how to write 3D array or image into binary raw file.
Is there a way to accomplish this in Mathematica?
Alternative_Answer for: ...
7
votes
1answer
494 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 ...
6
votes
2answers
395 views
Fit an image within a Rectangle [] in Graphics
Based on the following Code (yet the white text in the image is added with PPT), I would like to have an image fit within one of the rectangle.
For Example the image from there :
...
5
votes
3answers
259 views
Tile image on specific location without space between them [duplicate]
Possible Duplicate:
How to combine images with the same dimensions in a grid?
I would like to arrange images without any space between their edges as each piece is made to connect with ...
0
votes
1answer
82 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 ...
9
votes
2answers
303 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, ...
41
votes
5answers
5k 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 ...
25
votes
2answers
733 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 ...
33
votes
3answers
809 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 ...
22
votes
4answers
834 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.
...
12
votes
2answers
582 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:
...
12
votes
1answer
342 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 ...
24
votes
2answers
408 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 ...
17
votes
0answers
615 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 ...
15
votes
6answers
574 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:
...
11
votes
2answers
687 views
How to convert an image to a graph and get the positions of the edges?
I am trying to convert an image to a graph. My image is already skeletonized and looks pretty much like this:
What I need to do is identify all vertices and edges, and in particular get a list of ...
10
votes
2answers
527 views
Image Processing: Isolating areas of an image with internal irregularity
I am trying to isolate each of the blue painted fingernails in the image. However, I am not sure what approach should be considered due to the white design on each nail interrupting the otherwise ...
9
votes
1answer
753 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, ...
18
votes
3answers
938 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
530 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 ...
13
votes
3answers
452 views
Measure a DensityHistogram[] pair similarity
I study human vision and more specifically eye-movements.
"If we display 2 symmetrical patterns (20 min one after the other), will our gaze distribution be symmetric is my research question."
The 2 ...
16
votes
3answers
628 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 ...
13
votes
3answers
795 views
Filtering pixels of a certain color
What is the best way to filter an image so that only the pixels close to a certain color are left?
I've downloaded some satellite images from the web where a specific pixel color corresponds to a ...
13
votes
4answers
319 views
How to separate paths from the output of EdgeDetect?
I have been trying to find a way to separate the various closed paths that can be output by EdgeDetect. For example, taking the output of:
...
11
votes
2answers
481 views
Symmetrical image transformation for a kaleidoscope-type image
I've been trying to write a little kaleidoscope-type manipulate, using images rather than graphics, and using ImageTransformation as a way in. However, I'm starting ...
10
votes
1answer
426 views
Enlarge an image and increase its resolution
An ongoing purely recreational project. I got my introduction to image processing with this Rotating perspective... question and had a lot of fun with it.
Now I want to take it to the next step.
...
9
votes
1answer
159 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 ...
9
votes
2answers
158 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"]
...
7
votes
0answers
141 views
Proving (self) similarity with Mathematica - Reccurrence Plots, Similarity Plots etc
I posted this question in math.se but given the sheer tumultous number of questions that keep appearing on math.se and also given that I am trying to accomplish this in Mathematica, I thought I'd post ...
5
votes
4answers
135 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 ...
4
votes
1answer
333 views
Efficiently exporting many images as a video
I have many .gif images and I would like to export them as a single video file (I prefer .mov, but any video format is fine). But what if I have several tens of megabytes of .gif images? Is it ...
