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How does the Viola-Jones algorithm work?
The Viola-Jones algorithm first detects the face on the grayscale image and then finds the location on the colored image. With smaller steps, a number of boxes detect face-like features (Haar-like features) and the data of all of those boxes put together, helps the algorithm determine where the face is.
What is the accuracy of Viola-Jones algorithm?
Reese’s study concluded that the Viola-Jones algorithm achieved better performance, with average accuracy of 74.8% and average speed of 0.03 s per image, and suggested that more work could be done to improve the accuracy of the Viola-Jones algorithm for face detection from thermal infrared images.
What is the significance of cascading in Viola-Jones algorithm?
A Cascade Classifier is a multi-stage classifier that can perform detection quickly and accurately. Each stage consists of a strong classifier produced by the AdaBoost Algorithm. From one stage to another, the number of weak classifiers in a strong classifier increases.
Why is LBPH used?
LBPH is one of the easiest face recognition algorithms. It can represent local features in the images. It is possible to get great results (mainly in a controlled environment). It is robust against monotonic gray scale transformations.
How do you implement Viola Jones?
Viola-Jones
- Initialize the weights.
- Normalize the weights.
- Select the best weak classifier (based on the weighted error)
- Update the weights based on the chosen classifiers error.
- Repeat steps 2–4 T times where T is the desired number of weak classifiers.
Is LBPH a machine learning?
LBPH is one of the easiest face recognition algorithms. It can represent local features in the images.
How is the efficiency of the Viola Jones algorithm increased?
The efficiency of the Viola-Jones algorithm can be significantly increased by first generating the integral image. The integral image allows integrals for the Haar extractors to be calculated by adding only four numbers.
How are Haar basis feature filters used in Viola Jones algorithm?
This algorithm uses Haar basis feature filters, so it does not use multiplications. The efficiency of the Viola-Jones algorithm can be significantly increased by first generating the integral image. The integral image allows integrals for the Haar extractors to be calculated by adding only four numbers.
How big is Viola Jones face detection window?
The framework devised by Viola-Jones uses a base window of size 24X24, which leads to over more than 180,000 features being calculated in this window. It becomes very computationally expensive to calculate the pixel difference for all the features.
Which is the algorithm used for face detection?
Viola Jones algorithm is one which was used and which we have forgotten in light of stronger techniques. Voila Jones Algorithm did the things which became a cool thing after 2 decades In this post we will look at Face Detection and its widespread applications.