June 17, 2010

News and updates

Some users expressed the need for longer evaluation time, so I extended the trial period for Pixcavator from 10 to 30 days. Also, for the users who are having trouble with installation and registration, for a number of reasons (firewall etc), please try the Student Edition. It requires no installation and can be freely copied.

The site, Computer Vision Primer, has been growing and has reached 379 pages with 1,018 illustrations. In particular, the transcription of the Vector Calculus course that I taught 2009/10 has recently started. Two lecture sets are finished (about 20% of the total) and the third is on the way.

The NSF summer REU program has started. These are the two projects that I will supervise:

June 10, 2010

Quality of soldering: an image analysis example

Q: “Interested in assessing whether your software could be used to determine the quality of a solder joint… Joint is composed of an aluminum tube and a copper pipe… The area of the copper pipe that overlaps or contacts the aluminum tube is the area that needs assessment. Would like to determine what percent of this area has a solder coating. The solder is a zinc78%/alum22% alloy… the copper pipe section could be flattened to a greater degree if this to would help with accuracy.”

As it has been suggested, it is a good idea to outline what is to be measured manually so that we can see if automatic analysis produces reasonable results:

In the screenshot the two numbers are at the top.

The area inside the red contour (i.e., inside your red line) is 140,582 pixels.
The area inside the green contour (i.e., gray region) is 106,787 pixels.

So the proportion of gray inside the red line is
106,787 / 140,582 = 76%.

By moving the sliders one can make the contours to fit better and improve the accuracy.

More here