Measure size of objects in an image using JavaCV

The project provides a script to read an image and draw objects contours.

Constraints

1. Shadow effect: use dark background
2. Object boundry: use contrasting background

Getting Started

Prerequisites

1. Java 8 (maybe or higher)
2. Maven

Installing

1. Clone repository

• git clone https://github.com/evosystem-jp/objectSizeMeasurer.git

2. Install dependencies

• mvn install

Run

For image file

mvn exec:java -Dexec.mainClass="jp.evosystem.objectSizeMeasurer.mains.ImageFileObjectSize"

For video file

mvn exec:java -Dexec.mainClass="jp.evosystem.objectSizeMeasurer.mains.VideoFileObjectSize"

For web camera image

mvn exec:java -Dexec.mainClass="jp.evosystem.objectSizeMeasurer.mains.WebCameraObjectSize"

Algorithm

1. Image pre-processing

• Read an image and convert it it no grayscale
• Blur the image using Gaussian Kernel to remove un-necessary edges
• Edge detection using Canny edge detector
• Perform morphological closing operation to remove noisy contours

2. Object Segmentation

• Find contours
• Remove small contours by calculating its area (threshold used here is 100)
• Sort contours from left to right to find the reference objects

3. Compute results

• Draw bounding boxes around each object and calculate its height and width

Results

Authors

• Evosystem, Inc.

Acknowledgments

• https://www.pyimagesearch.com/2016/03/28/measuring-size-of-objects-in-an-image-with-opencv/
• https://github.com/snsharma1311/object-size