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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PrRoIPool vs RoIAlign with samling ratio 0 - Are they equivalent?

I had been trying to implement Precision roi pooling from this repository into my pytorch model. It turned out to be much harder than I anticipated so I ended up not using it. I read somewhere that Precision roi pooling does the same thing as Roi…
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ROI for image dataset

I'm trying to find out ROI for an image dataset. I'm able to find ROI for a single image, but when it comes to the whole dataset or multiple images I can't do it. I tried to use different code from the internet, but nothing worked. ` import…
717896
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How could I use multiple atlas for fmri classification using python

I am trying to do classification on autism fmri data by using multiple atlas. I have applied a python code for classification that is working well but now I want to do same thing by comparing multiple brain atlas. Like AAL, HO.
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The ROI seem to forgot to update its states after rotate and resulting in errors of setPosition

Code to reproduce import pyqtgraph as pg from pyqtgraph.Qt import QtCore, QtWidgets from pyqtgraph import PolyLineROI app = pg.mkQApp("Arrow Example") w = QtWidgets.QMainWindow() cw = pg.GraphicsLayoutWidget() w.show() w.resize(1600,…
陈扬航
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how to resolve "[WinError 2] The system cannot find the file specified" while making ROI by SCP

2022-09-06T15:53:28 WARNING Traceback (most recent call last): File "C:/Users/Baghban/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\SemiAutomaticClassificationPlugin\dock\scpdock.py", line 1736, in pointerClickROI …
s. bb
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Find best crop on image with multiple rois

Summary: What is the best approach to find the best cropping on image with multiple ROIS? Details: we have image size we have known ROI score an position on the image we have desired output ratio (portrait/landscape/square) positive ROI score…
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how to merge the background of uint8 image?

I am trying to do lung extraction from CT images. I would like to remove the background and keep only the lungs (the yellow color background must change to blue-ish color and lungs must have unique color). How can I do that?
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OpenCV Annulus region of interest

I defined annulus ROI selection function and i would like to find contours in this area. But contours pixel values are neighbors to the zero and out of masked areas equal to zero. Therefore contours couldn't be catch thresholded image. How can i…
Ali Ünsal
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Please tell me how to make the ROI moving. OpenCV, Python

I have written Python code that converts video to black and white mode. In the center of the video is a color ROI. I don't understand how to write a loop that will make the ROI move (any kind of movement) through the video, so that the pixels in the…
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Regarding Multiple ROIs in an image using python/opencv

When you select multiple ROIs in an image, how to display them all simultaneously in that image white selecting one by one? How to deselect some selected ROIs in that image at the same instance of selecting ROIs? some of the code I have written…
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Fill the center of ROI

How can I fill ROI, so that the image is placed in the centre of the ROI? The ROI is found with (x, y, w, h) = cv2.boundingRect(contour) and I insert the input image with image = cv2.resize(input_image, (w, h)) …
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Error with number of variables in objective and constraints

I'm trying to set up a linear optimization using the ROI package in R, following instructions in this link: https://roi.r-forge.r-project.org/use_case_portfolio_optimization.html#introduction. However i'm getting an error when trying to implement a…
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Is there a way to prevent a rectangular pyqtgraph ROI to not move left-right?

I have this snippet from part of a code I'm working on with pyqtgraph ROI. I have also set boundaries in which the ROI cannot cross on all sides. When I move either of the vertical scale handles, it gives the ROI an opportunity to move left-right if…
SorinT
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The correct way to define a ROI

I'm currently working on a image processing project opencv python based, and essentially it's quite simple, it uses cv2.matchTemplate and a database to make all the matches, but I think something is done wrong. The images are get from a few cameras,…
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Cropping a video to a specific range of frames and region of interest in Python

I have a video and I am only interested in a small section of the video (both in terms of a certain amount of frames and a small window of the video). I have been slowing chewing my way through problems, with the help of people in this thread and…
Chris
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