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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Kvazaar encoder - Reading ROI file failed

While trying this command: kvazaar -i video.yuv --input-res 1280x720 -o video_tiled.hevc --roi roi.txt --slices tiles I get this error: Reading ROI file failed. invalid argument: roi=roi.txt Any ideas? Thanks!
Sophie
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imageJ/FIJI: can i add a new ROI in the middle of a ROI manager list of ROIs

I have some code that processes saved lists of ROIs in a specific order. I am trying to go back through and add ROIs where they are missing but can only seem to add them to the end of the list of ROIs in ROI manager. Is there a way to add them into…
user3470496
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Matlab ROI Image Processing Approach

I currently have images of the following nature: The goal is to have the code display the mean value of each of the squares. The position of each square slightly shifts from image to image. The images are stored as 1024 x 1024 matrices (type =…
itend
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I have mistake "approxPolyDP(ROI_Vertices, ROI_Poly, 1.0, true)" in OpenCV

I don't know what I've done wrong. Mat mask(img.size(), CV_8UC1, Scalar::all(0)); // Create Polygon from vertices vector
김선일
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How to extract features from the region of interest of an image excluding the black background?

I was scrolling through some answers of the same issue and got the following C = num2cell(YourImage); C(~YourImage) = {{}}; This should give a cell array in which there are empty cells ("nothing") where the background was, and cells containing 1…
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OpenCv assertion failed about rect ROI

I am trying writing image rotation,but I have some problem right now. This is my code: Mat rotateMagnify (Mat& img, int degree){ double angle = degree * CV_PI / 180.; double a = sin(angle), b = cos(angle); int width = img.cols, height =…
Luo Zin-Han
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OpenCV ROI on Real time camera

I am trying to set ROI in real time camera and copy a picture in the ROI. However, I tried many methods from Internet but it is still unsuccessful. Part of my code is shown below: while(!protonect_shutdown) { …
xuxin wang
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ROI is written in lighter colors than original picture

I'm trying to locate an object (here a PWB) on a picture. First I do this by finding the largest contour. Then I want to rewrite solely this object into a new picture so that in the future I can work on smaller pictures. The problem however is…
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How to manually label ROIs in Training Image labeler?

I am new to Matlab. I want to label several images to use in SVM training later on. I have decided to use ROI but i can't label my ROIs. I have objectBoundingBoxes column but i want to have object column and not_object column seperately. Or…
cinemaniac
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Matlab: how to save the image result Real-time plotting of ROI selected with IMRECT

I am confused about how to save the ROI resulting from calling imrect. I want to save the image on subplot(2,1,2) The code is: function Zoomer figure(); highResImage = imread('E:\My Work\THESISQ\FIX\Koding\data coba\Image_3060.jpg'); lowResImage =…
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How to select section of a sector as a region of interest in OpenCV using python?

I want to extract a single cell of this maze as a region of interest. Assuming that each level of the maze has equal width how can I do so? My approach was to calculate the value of four corner points of the cell and draw a custom mask using the…
Deeksha
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Return type of Region of Interest?

I am a beginner in OpenCV and am facing this difficulty. Recently, I wrote a code in which the function makes a region of interest of a specified image. def detectCellVal(img,x): for k in range(0, 6): for j in range (0, 6): …
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Any way to automatically calculate Annular regions of nerve cells in ImageJ?

I'm trying to do a particle analysis of cross section of nerve cells. In essence, each nerve fiber has an outer and inner radius and I want to calculate the annular region. It's fairly simple to convert the image to a binary one, and then analyze…
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Region of interest in

I'm a developing an application using jasper library and i need to encode ROI some ROI (region of interest). I read in the jasper official website https://www.ece.uvic.ca/~frodo/jasper/ that, only the decoder support ROI. But i saw in the jpc codec…
user6684929
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How to stitch images with differing orientations

I have a set of images collected from a drone that I now want to stitch together. The approach I started going towards is to rotate all the images to the proper orientation, then try to stitch those together. However since the rotated images are no…
Noremac
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