Tag for questions about bitmapped graphics, particularly those using the Image function.

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39
votes
3answers
1k views

Composition à la Mondrian

I would like to paint something like this or,even better, like this I have tried ...
29
votes
3answers
5k 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:
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.
25
votes
7answers
3k views

Embed Code Into Image

I often export images(plots, matrix, arrays, etc..) from mathematica which I end up putting in word documents or uploading to the web. The problem is that I often lose the original code and I am left ...
23
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 / Optica? ...
23
votes
3answers
1k views

How to place an image inside a notebook, with the minimum memory footprint?

When creating a notebook with images, like photos, the file tends to quickly get big, which makes it difficult to use the notebook format for training material containing a lot of images. Are there ...
23
votes
1answer
2k 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 ...
22
votes
4answers
3k 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 ...
21
votes
4answers
2k views

Efficiently generating n-D Gaussian random fields

I am interested in an efficient code to generate an $n$-D Gaussian random field (sometimes called processes in other fields of research), which has applications in cosmology. I wrote the following ...
21
votes
2answers
910 views

How to generate a picture like this?

How to generate a picture like this? I'd like the surface of the manifold to randomly distort.
19
votes
2answers
788 views

Why does ImageData need four times more memory?

Background We are dealing with very large TIFF image files that are imported, processed and exported using Mathematica 9.0.1. Many of our algorithms only work with an array representation of the ...
18
votes
1answer
554 views

When exporting an (animated) GIF, is it possible to specify the size of the color palette?

I've exported an animation to animated GIF, which generated a 15mb file. I've been asked if I could regenerate the file, limiting it to only 16 colors, but I can't find any documentation on how I ...
17
votes
3answers
823 views

How to make a pie chart using custom image

Can we make a pie chart using a custom picture? For example, consider this image of one cent coin: I would like to use this image and cut pieces out, depending on data, and also make a clickable ...
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 ...
16
votes
1answer
611 views

How to identify chemical substance from tattoo?

A friend of mine made a tattoo on his chest of some chemical substance formula. He challenged us to identify which substance is that. I thought that perhaps a combination of: Mathematica image ...
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: ...
16
votes
1answer
971 views

Slow import of multigigabyte TIF image stacks

Update 6: After contacting Wolfram Technical Support, I was advised that the frame-to-frame import timing variability can be eliminated by reading in the frame stack from frame to frame with the ...
14
votes
2answers
379 views

How to load thumbnail, not image?

Is there any way to import only the thumbnail of an image instead of the full image? I frequently work with lots of images and it would be nice if the contents of a directory could be quickly ...
14
votes
2answers
278 views

SaveDefinitions->True changes the displayed image

Bug introduced in 9.0.1 or earlier and persisting through 10.1.0 or later I have a Manipulate[ ] that displays an image with a superimposed ...
13
votes
3answers
904 views

How can I convert colors to grayscale?

I want to change the above colored plot into a grayscale plot. I have tried this: CCGray[pic_?ImageQ] := Module[{}, ColorConvert[pic, "GrayScale"]]; but it ...
13
votes
1answer
991 views

How to map an image to get an illusion of 3D

I would like to distort or map a given jpg so it looks 3D when viewed from certain angle, as in the following youtube video: http://www.youtube.com/watch?v=IfCCUd8mFtg. The most interesting part of ...
13
votes
2answers
551 views

Sharp background image in plot

How do I get rid of blurry transitions between pixels of the background image below. It's the fault of Texture[], previously discussed in this answer. I haven't ...
13
votes
1answer
311 views

High memory use while exporting a BMP

Something mysterious is going on when exporting images. I'm using Mathematica 9.0.1 on Windows 7 (64 bit), and find that the memory use is excessive when exporting to a bmp. But it doesn't happen ...
12
votes
4answers
566 views

Using an Image as the Fill/Texture (not background) of a Plot (not polygon)

Is it possible to use an image, rather than a color, or ColorFunction, as the filling for a plot? For instance, I want to make a plot using ...
12
votes
3answers
555 views

Apply an image as a texture to text

I have the following equation eq = Sum[x^2, {x, 0, 10}] and an image ...
12
votes
3answers
702 views

How to mark an image?

How can I place a mark, like a cross-hair (to suggest "X marks the spot") and a text label associated with it, at a particular position on an image (mine in particular is ...
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 ...
12
votes
1answer
619 views

Ellipse counting from image

I have hundreds of images similar to this image: I'm looking to count the number of ellipses as well as their major and minor diameters. The ellipses are touching, hence, ...
12
votes
1answer
257 views

How can I detect if an image is in or out of focus?

I need to filter out bad (blurry or ) images from a set, with some sort of blur detector.
12
votes
2answers
1k views

Failure to export graphics by right-click when Notebook magnification is changed

Bug introduced in 9.0.1 or earlier and persisting through 10.1.0 or later When I try to export graphics as PNG, JPG and other rasterized formats using the right-click and choosing ...
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 ...
12
votes
1answer
214 views

Raster to Image conversion problem

Bug persisting through v.10.2.0 There are 3 ways to convert a Raster into an Image : only 1 works for me with version 10.0.1,10.0.2,10.1.0 , and 2 work with ...
11
votes
2answers
365 views

How could I use Mathematica to remove finger tips that appear in images?

I used my photo camera to "scan" a heavy dictionary. I tried to have flat images by pressing the margins of the pages with my fingers. The color of the background is (normally) black and my fingers ...
11
votes
3answers
3k views

Composing an image with a plot

I'm trying to illustrate the solutions to a textbook problem dealing with quadratic functions. This will involve plotting a quadratic and overlaying the plot and the image. Here is the textbook ...
11
votes
2answers
834 views

Maximum size of TIF files in Mathematica

I have a question concerning the maximum size of TIFF files Mathematica can handle. According to the TIFF 6.0 specification -revision 6.0 (see: ...
11
votes
2answers
799 views

How to improve the accuracy of this Monte Carlo simulation

A friend of mine went on an interview and he was asked to calculate the angle between the hour hand and minute hand of an analog clock when the time was 3:15. Arguably, this is a trivial problem that ...
11
votes
1answer
997 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. ...
10
votes
3answers
298 views

Best method to find variation in width along the image of a slit?

EDIT: Solutions by @Alexey Popkov and @Vitaliy Kaurov are very intuitive and both can be used to find a solution for the task. I have a slit of 15-18 microns by 1 mm projected with magnified 4X onto ...
10
votes
2answers
529 views

Generating uniform random points over a binary image

So I recently read this excellent post about generating random points over arbitrary regions. I hope Wolfram eventually builds that functionality into Mathematica's Random functions. I want to do this ...
10
votes
4answers
4k views

How to convert rgb to YCbCr?

I looked at ColorConvert, but haven't found a relevant option. Is there a built-in function do this?
10
votes
1answer
348 views

How can I extract the outline of bubbles in my image?

I have an image: I tried to extract the outline of the bubbles, but I met with some problems. Firstly I tried the method used in Mathematica documentation for ...
10
votes
2answers
1k views

Rasterizing a plot make axes ticks invisible

I've evaluated this code: plot = Plot[x, {x, 0, 10}]; g = Rasterize[plot, ImageResolution -> 300]; Everything looks good except the ticks (on the axes); they ...
10
votes
4answers
304 views

Why do quote marks appear in output when saved with Save Selection As?

Update #2: This behavior has been confirm across platforms and in multiple versions. Therefore: Is this a bug or a feature? Can I disable this "feature" so that copying a selection of Cell contents ...
10
votes
2answers
743 views

Detecting edge/region in contour plot

I am interested in improving this plot: which I produced with the following command: ...
9
votes
4answers
676 views

Measure the length and width of the image

I obtained the images from a Magneto Optic Kerr Effect system from which I have to do some calculations. I cannot calculate the desired information from the images. The details are as follows: From ...
9
votes
5answers
399 views

How to resize the text content of a grid with it?

I am in a resizing mood these days. This code works quite well, up to a point. ...
8
votes
4answers
702 views

Image correlation

I have two images from motor scan, Image1 is shifted by MxN pixels from Image2. How can I find the shift between Image1 and Image2 ? Image -1 Image -2 If we compare the shift between the images ...
8
votes
3answers
976 views

Line Intensity Profile From Image

I can get line profiles from images using imagej but it would be nice to be able to do this in my mathematica notebooks. I found this http://library.wolfram.com/examples/intensityprofiles/ after ...
8
votes
3answers
981 views

256 Shades of Grey

I noticed that the following line, Image[Table[x, {y, 1, 250}, {x, 30/256, 40/256, 0.02/256}], Magnification -> 1] results in the following image: In the ...
8
votes
1answer
326 views

Export an image at 1000 dpi

I'm trying to export an image at 1000 dpi. The author guide of a lot of papers wants this resolution! Then I must to import this image in Word in a small box; let's say 7x4 cm. This is the code that I ...