weld camera, WeldStudio, software

Using Edge Filters on Weld Camera Images

Cameron Serles
Written by Cameron Serles on April 16, 2020

Xiris Weld Cameras generate video that allow operators to monitor their welding process remotely.  Sometimes it can be difficult to see subtle features or detect details of the weld process that can be used by the operator to adjust the process.  Advanced Edge Detectors are software tools that highlight regions in an image of rapid image brightness changes.  Such tools can be applied to weld camera images to see subtle features in the welding environment not easily seen by the human eye.

With its latest version of Weldstudio™ software, Xiris provides three advanced edge detectors to support its Weld Cameras:

Sobel is a mathematical operator that convolves the original image with a kernel in the horizontal and vertical directions to create a new image.  Each point in the new image is an approximation of the gradient of the area in the immediate vicinity of the original image.  It provides a relatively crude gradient value that works best for low frequency variations in an image.

Sobel 1 Sobel 2

Original Image of a TIG Weld Process (left) and after a Sobel Filter

Canny is a function that convolves the original image using a multi-stage algorithm that detects a wide range of edges in an image.  It is a powerful technique to extract useful structural information from different objects in a weld scene and dramatically reduces the amount of data to be processed.  The Canny algorithm provides good and reliable edge detection that is particularly useful in accurately catching all edges, in the precise location, while generating minimal noise.

Canny 1 Canny 2

Original Image of a TIG Torch (left) and After a Canny Edge Detector

Hough Line is a feature extraction technique that finds imperfect instances of lines in region of interest in an image using an algorithm that implements a voting procedure to determine which pixels are part of a line object. The voted pixels are then assembled together as a line.  This can be very useful for detecting lines in an image, for example finding the edges of a seam to be welded.

Hough 1 Hough 2

Original Image of a TIG Torch (left) and After a Hough Line Detector

These three new powerful advanced edge detectors (Sobel, Canny, Hough Line) have been implemented in the Weldstudio™ software utility allowing users to precisely locate different kinds of edges or highlight subtle features that can then be extracted through further processing of weld videos generated by Xiris weld cameras.

For more information contact us or request a free, one-on-one, no obligation consultation!


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