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

441 questions
0
votes
0 answers

Pointer using Mat in OpenCV

I would like to get a pointer(*A) of a Region of interest in an Image( I ). It is good for me because I can atribute this region for an other Mat M(Same size that region *A). I would like, for example to sum the original region for M: *A += M; It…
DualSim
  • 279
  • 2
  • 4
  • 7
0
votes
2 answers

How to use points / scene corners of homography as input for ROI in another function

I want to perform object tracking after recognition, currently im able to recognize an object an draw lines around the object.I would now like to use these four points(scene corners) calculated in perspective transform as input for computing ROI and…
Darshan
  • 1,018
  • 10
  • 19
0
votes
1 answer

How to crop a specific rectangle portion(ROI) from an image in OpenCV c++

Actually I need to crop a rectangle portion in an image. I am having two points p1 and p2 of the rectangle. After cropping the rectangle I need to store that one for further reference.
Somashekar
  • 31
  • 1
  • 8
0
votes
1 answer

How to save ROIs from ROI manager in jython script?

I'm writing a semi-automatic juthon script. At some point the script stops waiting for the user to manually add a few ROIs. What I need is a method to save all the ROIs added to the ROI manager. I have tried the…
0
votes
2 answers

Apply changes of ROI to original image

My task is to perform some operations on the roi of an image. But after performing these, I want the changes also to be made visible in the same region of the original image (in code called "image"), not just in the roi as seperate image (which is…
0
votes
1 answer

How to effective modify my ROIs

I have been working on a program that will be used for my research needs. There is one last step, which I can not solve by myself. On the image you can see two ROIs that were selected based on macro Link: Automatically recognized objects…
JerryTheForester
  • 456
  • 1
  • 9
  • 26
0
votes
3 answers

How to get the coordinate of bright or dark pixels? OpenCV

I'm trying to get the coordinate of the white n black pixels from a binary image so that i can get the ROI of the image and alter the pixel values. Any function that I can call? This is the original image After that it'll be thresholded using OTSU…
user3396218
  • 255
  • 2
  • 8
  • 20
0
votes
1 answer

Non-region of interest with Mat Image in OpenCV

I want to get features from non-region of interest area. I know how to define ROI in Mat format, however, I also need the rest of the area for negative image features.Thanks in advance.
garnettburak
  • 143
  • 1
  • 9
0
votes
1 answer

How to enlarge ROI imagej macro

I would like to enlarge several rois with the following loop: counts=roiManager("count"); for(i=0; i
JerryTheForester
  • 456
  • 1
  • 9
  • 26
0
votes
2 answers

"Sometimes" getting garbage value for an integer type varibale in openCV

I build a program using the basic idea of detecting squares from square.c of openCV samples. I detect the squares in CvSeq* and then i calculate the minimum_x, min_y, width and columns to create seperate image for each detected square. Problem: But…
skm
  • 5,015
  • 8
  • 43
  • 104
0
votes
1 answer

Find X and Y coordinates of point in relation to the whole image

I trying to find nose tip landmark inside 2D image. It's not working 100% correct, but as first approach it fully satisfy me. vector noses; vector faces; vector eyes; Mat frame_gray; Mat matched_frame; //frame with matched…
Michal_LFC
  • 649
  • 3
  • 11
  • 25
0
votes
1 answer

How to mark objects that are touching the edge to be able to treat them differently in later analysis

I have one challenge for all advanced ImageJ users and developers. In my macro (see macro below) I would like to insert the following task: I am analyzing particles in ROI and those particles/objects that are touching the edge of the picture, I…
JerryTheForester
  • 456
  • 1
  • 9
  • 26
0
votes
1 answer

Each ROI Analyze particles in separate output file; ImageJ

Hello to all from Slovenia! My issue: I am running particle analysis in different ROI using the following macro: id = getImageID(); for (i=0 ; i
JerryTheForester
  • 456
  • 1
  • 9
  • 26
0
votes
1 answer

Extract multiple ROI pixel value from multiple images

I have a programming challenge out of reach of my very stammering Matlab expertise. I have a list of images and list of ROI mask in a cell array, and I want to extract mean pixel value of each ROI individually, My code goes like this…
0
votes
1 answer

Spatial Transform to ROI in MATLAB

I'm looking for a way to apply a spatial transform to multiple ROI's in based off an image. What I have is a predefined image which has multiple ROI's specified on it, and another image that is not set which we match to the original and transform…
Gbru
  • 97
  • 1
  • 8