3DCube

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Image Processing Software

Contents

What is it?

3D Cube is a system for acquiring measurements from image data. The objective of this project is to quickly determine the volumetric data of an object using high resolution camera with as little operator intervention as possible.

Currently the only supported input format is .png, however the software may be easily adapted to accept images directly from high resolution cameras or video sources.

Background clutter, writing, etc... will not affect detection so long as there are no other rectangles in the image larger than the one being measured. The rectangles can be at any angle between -30 and 30 degrees and still be detected accurately. The box must be generally centred in middle of the image however a great amount of offset is allowed, so long as the each edge of the box is in a different quadrant of the screen measurements will not be affected.

Box and its measurements...
Measurements of irregularly shaped box
Perfect measurement of CD
Another misshapen box

How does it work?

In the most basic sense, the system first identifies all straight edges within the image using various filters and the well documented Hough Transform which is able to detect lines even in otherwise cluttered images. Next it finds the largest rectangle formed by these lines and from that the size of the box can be determined in pixels. This combined with height information obtained either via lasers, stereoscopic cameras, or using multiple light sources and shadows can be then used to obtain volumetric information.

The process actually involves about two dozen individual procedures. These procedures and settings may be adjusted in order to allow less or more perfect rectangles to be found. In this way accuracy can be increased depending on the application. Some of these steps may be observed during program's operation such as binary conversion of the image.

Original image of Brookyln bridge before binary conversion.
Lines found in image after binary converstion and applying the hough transform.
Demonstration of Hough's inner workings. Image on right represent votes for various lines lines, bright spots are the have most votes. This is commonly refered to as Hough space.

Can it find other shapes?

It is possible with some reprogramming to allow accepting any numbers of sides, even circles. In some cases, this may slow the process down.

The images on the right shows how other images may be detected.




Original star image.
Lines found from image.

Download

3D Cube's startup screen.

3DCube is written for Windows but will run fine and was even developed under Wine on linux. currently offered in executable format only. The archive contains the .exe as well as several images for testing and evaluation. Any image in .png format may be used.

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