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

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30
votes
3answers
6k 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:
23
votes
4answers
3k 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. Attempt I wrote the ...
27
votes
3answers
2k 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 ...
15
votes
2answers
2k views

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

Bug introduced in 9.0.1 or earlier and persisting through 10.3.0 or later When I try to export graphics as PNG, JPG and other rasterized formats using the right-click and choosing ...
1
vote
2answers
7k views

Calculate the 2D Fourier transform of an Image

I am new to Mathematica, and using version 8.0. I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase ...
32
votes
7answers
5k 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 ...
11
votes
3answers
2k 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
2answers
380 views

Using a given colour table with Image?

Context I would like to represent large images with a given colour table. Now, if I use Image ...
8
votes
2answers
1k 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, ...
16
votes
2answers
6k 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: ...
18
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 ...
25
votes
4answers
4k 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
2answers
896 views

video image recognition [closed]

Has anybody experience with video and image recognition? I've made a video of two teams playing soccer. Now I would like to translate each soccer-player to a (x,y) coordinate and follow them during ...
6
votes
1answer
215 views

Is it possible to render Graphics with more than “Byte” bitdepth?

I wonder is it possible to render Graphics in Mathematica with bitdepth higher than "Byte" which is the maximum bitdepth ...
2
votes
1answer
289 views

How to highlight image edge with spline/bezier when mouse moved over?

It is known that EdgeDetect can find image edges in an image. Suppose the image edges consists of sets of lines. Can the detected edge line near the mouse pointer be highlighted as spline/bezier when ...
0
votes
1answer
388 views

Reverse after ImageData? [duplicate]

Why should we do a Reverse on the image data after an ImageTake ? For example: ...
31
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.
18
votes
1answer
1k 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 ...
13
votes
1answer
734 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, ...
13
votes
3answers
4k 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 ...
12
votes
1answer
544 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
4answers
1k 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 ...
6
votes
3answers
255 views

Inconsistent image sizing with Grid and Row?

Can anyone explain why Row and Grid don't size the image correctly and consistently to 300 ...
5
votes
1answer
240 views

HOWTO encode/decode large chunks of Mathematica code/results e.g. for posting on sites?

At times, we as questioners would like to post huge Mathematica-expressions to websites (e.g. mathematica.stackexchange.com), or have an easy way to get such code from a site. Above a certain size, ...
10
votes
4answers
6k 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?
5
votes
2answers
151 views

Problem with Raster and custom ColorTable

Context Let me define two colour tables: (which come from brewer and xmedcom respectively) ...
8
votes
1answer
509 views

transparency in image used for texture?

Is there a way to set a transparancy channel in a raster image used for a texture in 3d graphics? this creates a raster image with a transparency channel: ...
6
votes
0answers
268 views

Bug report: Attempting to Save Selection As… in a magnified Notebook fails with errors [duplicate]

Bug introduced in 9.0.1 or earlier and persisting through 10.0.2 or later I have found that attempting to Save Selection As... in a magnified Notebook fails with errors. On my system it can be ...
6
votes
2answers
456 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 ?
3
votes
2answers
499 views

Color Transfer from colored image into grayscale image

At first I did this where image is a grayscale image and example is a colored image ...
16
votes
2answers
1k 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 ...
20
votes
2answers
897 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 ...
7
votes
2answers
444 views

Band Intensity Quantification

I would like to measure the density of my western blot band by measuring the area under the peak from this plot. More specifically, my image will have several lanes with a pattern of bands in each ...
13
votes
1answer
1k 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. ...
3
votes
2answers
1k views

Generating x,y coordinates for an edge detection

I'd like to be able to process a number of graphics that have edge contours and output a list of $x$, $y$ coordinates to be used for generating a spline in another program, or in Mathematica, to make ...
10
votes
2answers
901 views

Detecting edge/region in contour plot

I am interested in improving this plot: which I produced with the following command: ...
9
votes
1answer
263 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 ...
5
votes
1answer
217 views

Trace one point's coordinate values in sequentially images

I am a research student in a university. I think I need some help. I used a video camera to monitor the vibration of a plank. Then I should calculate the amplitude and frequency of the vibration ...
3
votes
1answer
1k 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 ...
9
votes
5answers
548 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. ...
4
votes
1answer
256 views

How to change the aspect ratio with drawing tool?

I'm drawing an image in editing an slide show with the drawing tools. But the aspect ratio of the created drawing seems fixed and not changeable with mouse dragging the border and corner as in other ...
3
votes
2answers
243 views

How can I capture a rectangular area from an image?

I am looking for a method to extract rectangular areas from an image. The image is divided up into rectangular problem spaces like the image shown below. Each numbered problem is given with some text ...
10
votes
3answers
387 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 ...
6
votes
2answers
388 views

How to add a graphics frame to an image without resampling

Using Inset to place an image inside a Graphics expression with Frame -> True provides a ...
5
votes
1answer
193 views

Force size in pixels of plot area excluding axes and labels

I have a matrix where each element represents a pixel. I want to plot the matrix (possibly with ArrayPlot). To suppress aliasing in the final graphic (which I will ...
2
votes
1answer
389 views

Selecting morphological components, of a certain size, centered on points of interest in an image

I have a set of points in an image, for example: ...
10
votes
4answers
317 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 ...
7
votes
2answers
227 views

How to resample a list of Images

I have a list of picture(Noting the ordering) first: second: third: forth: My target is get the 3D'image,Now I get the mask of it like following(If you use ...
7
votes
1answer
372 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: ...
6
votes
3answers
1k views

Understanding Bilinear ImageResize

In trying to understand basic image transformations, I have attempted to code my own image resize function that uses bilinear interpolation. I checked my work against Mma's ...