# Category Archives: opencv

## The average of an angle… (mean of Hue Value)

My solution to this issue was to write a bunch of code to handle the behavior of the average calculation at the 0 and 360 points. It was a pain in the neck, and I probably have it wrong :(. … Continue reading

## Homography Aided Plot Based Phenology Measurements

Before going home yesterday I left a process running that had the latest version of the homography algorithm.  The new trial included multiple markers and changing the way of calculating the image transformation.  When I arrived this morning, I found … Continue reading

## About HOG transform in opencv2.2

This post could also be titled: “Why I’ve decided not to use the HOGDescriptors from opencv”.  There are three main reasons why I chose not to use the provided HOG functionality in Opencv: What is in Opencv is not only … Continue reading

Posted in opencv, PhD | 2 Comments

I was surprised that this function was so difficult to find.  I googled with the title of this post and did not find any real solution to what I was looking for.  I just want to add some pixels of … Continue reading

Posted in opencv | 1 Comment

There were some issues with some of the classification tests I ran on the chessboard pictures from last week (you can find pictures here).  The ones that were taken from a distance of a couple of meters or less, classified … Continue reading

## Image labeling is taking shape.

After discovering that the accuracy of the chessboard detection is increased by adding a black frame around the chessboard, I went on to create a python library based on what I already had.  I created a python/C++ interface and some … Continue reading

## Chessboard format

It’s reasonable to describe the chessboard format.  It’s relevant because not all chessboard dimensions are valid,  The current implementation only detects 6 colors and there needs to be a black margin around the chessboard (among other reasons). Chessboard dimensions: We … Continue reading

## Unexpected solution to a detection problem

Before leaving for vacations I was fighting a very curious issue with my chessboard detection algorithm.  All my tests were done with pictures of chessboards that occupied most of the image.  The tests where very positive even for outside picture … Continue reading