abstract = "Feature extraction is essential for solving image
classification by transforming low-level pixel values
into high-level features. However, extracting effective
features from images is challenging due to high
variations across images in scale, rotation,
illumination, and background. Existing methods often
have a fixed model complexity and require domain
expertise. Genetic programming with a flexible
representation can find the best solution without the
use of domain knowledge. This paper proposes a new
genetic programming-based approach to automatically
learning informative features for different image
classification tasks. In the new approach, a number of
image-related operators, including filters, pooling
operators and feature extraction methods, are employed
as functions. A flexible program structure is developed
to integrate different functions and terminals into a
single tree/solution. The new approach can evolve
solutions of variable depths to extract various numbers
and types of features from the images. The new approach
is examined on 12 different image classification tasks
of varying difficulty and compared with a large number
of effective algorithms. The results show that the new
approach achieves better classification performance
than most benchmark methods. The analysis of the
evolved programs/solutions and the visualisation of the
learned features provide deep insights on the proposed
approach.",
notes = "School of Engineering and Computer Science, Victoria
University of Wellington, Wellington, New Zealand