Questions tagged [roi]

Region Of Interest, a region of an image on which algorithms are executed on.

Region Of Interest (ROI) is a selected subset of a data set identified for a particular purpose and is commonly used in many application areas. The data set could be any of the following:

  • 1D data set: a time or frequency interval on a waveform
  • 2D data set: the boundaries of an object on an image
  • 3D data set: the contours or surfaces outlining an object (a.k.a. the Volume of Interest (VOI)) in a volume
  • 4D data set: the outline of an object at or during a particular time interval in a time-volume

Tag Usage:

An ROI on an image can be defined in different formats, like a , a or a set of . The tag is commonly used in question related to or . An ROI can be defined to:

  • Restrict the region of the data set that an algorithm is applied to and avoid unnecessary calculations. (e.g., in an )
  • Identify/Annotate a part of data set. (e.g., locate moving objects in )
  • Extract additional information from the data set. (e.g., measure size of a tumor on a medical image)

An Example:

ROI locates the boundaries of a registration plate (it's Persian), this area will be used for ANPR:

enter image description here

Additional Reading:

Region of Interest on Wikipedia

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Insert binary threshold image (CV_8UC1) into a ROI of a coloured mat (CV_8UC4)?

I've got a sequence of images of type CV_8UC4. It is of HD size 1280x720. I'm executing the bgfg segmentation (MOG2 specifically) on a ROI of the image. After the algo finished I've got the binary image of the size of ROI and of type CV_8UC1. I want…
Grigory
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Displaying part (ROI) of the frames in real time

I'm trying to display the center 1/3 of my phone's screen on real time, like this: https://i.stack.imgur.com/qDdAb.jpg The idea is to limitate the user view to 1/3 of the screen, in the center (vertical). I've trying to do the precessing in the…
Android89
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Copying an Image to PictureBox using ROI EmguCV C#

I want to copy an image from camera to anothe imagebox using ROI. I have searched a lot references about ROI but it still doesn't work. Anybody can help me, please ? These are what I have done Image sourceImage1 =…
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Imrect doesn't get the correct size

I am showing an image so the user can select different ORI with the shape of rectangles always. My problem is that when I see the results of getPosition it gives me an x, y, width and height strange because if I use these numbers to extract this…
Learning from masters
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Measure multiple ROIs in imageJ

I'm creating a script for automated measuring fluorescence intensity. I have done some progress, the macro opens the image, split in as many channels as I have and perform some trasformation so that it is possible to execute particle analysis at…
Santi
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How to find the imrect rectangle position changed or not?

I am working on imrect function in matlab to display canny and sobel edge of ROI of imrect rectangle . Actually I have two axis in my matlab gui. In one axis I am displaying user selected image and placing initial rectangle using imrect function on…
saimadhu.polamuri
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ROI selection in ImageJ macro

I am trying to record a macro on Fiji (ImageJ). I cannot find how to introduce the use of the mouse for a ROI rectangular selection. The macro keeps the registered position, in the example (2290, 1224 , 160, 314). I want them to be different for…
catindri
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how to count the pixels in roi opencv

I have an cropped image of a coin. and I've already applied mask so i can focus on the coin itself. Next is I want to count the number of pixels of this coin. I've already read similar posts but i they just don't seem to work for me. here is the…
lionking
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Obtain rectangle ROI from object/mask opencv

I aim to obtain a ROI from a Mat. This Mat is expected to have a expected convex silhouette inside it. As example: Being the red rectangle the ROI I want to obtain, in order to cut this part of the image and work only with it. I've tried using a…
Btc Sources
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Opencv ROI fills more than it should

When I try to set frame ROI it fills up empty pixels, from given x to the end of input image. ROI is extracted well, can anyone tell me why isn't it 30 pixels wide as it should be? Image is resized from original size to 640x360. resize(frame, frame,…
Moirae
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Why can't I just add two ROIs in the image?

I need to add two ROIs in one image using the "Rectangle ROI" button in the toolbar. But I find that when I try to add the second ROI, the first one loses. What's the problem? Can I simply use the button to add two ROIs in one image? How? Or, must I…
R_eF
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Converting subsripts and indices

I'm having a hard time figuring out transformation between spaces using ind2sub and sub2ind. Could someone help? The problem is as follows: I have a mask Y (or region-of-interest) in which voxel values are either 1 or zero: Y=72x72x33 double. I then…
A.Rainer
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How to incorporate ROIs into an imageJ plugin?

I'm new to java so please forgive me if this is a stupid question! I'm writing a plugin relevant to my project to help me learn java/writing plugins for image analysis, and essentially want to restrict the measurements I'm taking to ROIs/Overlays,…
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How to Do Live FFT of sub-area (ROI) of a Image using DigitalMicrograph script

I mean both the sub-area change and the data change will trigger the FFT process, so I can see sub-area FFT of a Live Image.
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What's the ROI of Sub-Repositories?

I know that sub-repositories save you an your team time, but what is the ROI on them? https://www.mercurial-scm.org/wiki/subrepos
leeand00
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