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

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26
votes
5answers
958 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.
24
votes
3answers
3k 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:
22
votes
7answers
2k 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 ...
22
votes
3answers
986 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 ...
21
votes
1answer
1k 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 ...
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 ...
19
votes
2answers
787 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
662 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
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 ...
17
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)?
17
votes
1answer
477 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 ...
16
votes
1answer
738 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 ...
15
votes
2answers
2k 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: ...
15
votes
1answer
680 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 ...
14
votes
2answers
340 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 ...
13
votes
1answer
504 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 ...
13
votes
2answers
382 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
283 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
3answers
451 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
490 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 ...
11
votes
3answers
516 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 ...
11
votes
2answers
1k 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 ...
11
votes
1answer
441 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, ...
11
votes
2answers
698 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
586 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
366 views

Map of Specific US States? (Isolated)

My question here is fairly basic, and I'm sure I'm overlooking something basic. I know about CountryData for creating shapes of entire countries, and it works, to ...
11
votes
1answer
757 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. ...
11
votes
2answers
223 views

SaveDefinitions->True changes the displayed image

I have a Manipulate[ ] that displays an image with a superimposed Locator object. It works fine when I have ...
10
votes
4answers
2k 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
2answers
697 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
1answer
293 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 ...
10
votes
2answers
571 views

Detecting edge/region in contour plot

I am interested in improving this plot: which I produced with the following command: ...
9
votes
2answers
292 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 ...
9
votes
3answers
2k 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 ...
9
votes
4answers
431 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 ...
8
votes
5answers
289 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
3answers
701 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
279 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 ...
7
votes
4answers
721 views

MATLAB To Mathematica: How to implement imshow()

I want to implement the MATLAB imshow function in Mathematica. This is a DensityPlot[] from Mathematica And this is ...
7
votes
1answer
519 views

How can this type of optical illusion be created in Mathematica?

I see these around the web and would like to make them in Mathematica. Combining them in an array is actually quite mesmerizing!
7
votes
3answers
435 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 ...
7
votes
1answer
226 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 ...
7
votes
3answers
410 views

Combining Image3D and Graphics3D

I want to combine an Image3D and a Graphics3D using Show. Here is the code: ...
7
votes
2answers
256 views

Reconstructing an image from overlapping patches

The Mathematica function ImagePartition can create overlapping sub-images with the pixel offset options {dw, dh}: ...
7
votes
2answers
114 views

Export Grayscale Bitmap

I have a grayscale (one channel) image in Mathematica. How can I export it as a grayscale Bitmap? Every single option I tried so far does not have an influence on the Bitmap exported using ...
7
votes
1answer
285 views

Color ramp banding in PDFKit when exporting Raster image Inset to PDF

Here I produce a Raster image with large uniformly colored rectangles and put it in an Inset: ...
7
votes
3answers
312 views

Poor quality Rasterize output when Background -> None

I am attempting to generate partially transparent images for PNG Export, but seem to run to the following issue. If I Rasterize ...
6
votes
2answers
363 views

Rectangle with rounded edges

Inspired from : Fit an image within a Rectangle [] in Graphics I would like now to fit an image within a Rectangle[] with rounded edges as shown in the example below : Is it possible ?
6
votes
2answers
584 views

How do I display imported images at actual size?

I know that this is an extremely basic question, but I am having a lot of trouble finding the answer in the documentation. When I import an image (for example, ...
6
votes
2answers
426 views

How can I make a list animation of images that fade in and out?

I'm not sure how to get a "fade in" effect.