Image classification method and apparatus, and method and apparatus for improving training of an image classifier

Abstract

An image classification method comprises: extracting a logic program from a CNN, trained to classify features in images, which is a symbolic approximation of outputs of kernels at an extraction layer of the CNN; deriving kernel-based classification rules; forward-propagating pairs of feature-labeled images through the logic program to obtain kernel activations at the extraction layer for features in the images, where the scene in one of the pair contains a particular feature and the other is of the same scene without the feature; and calculating the correlation between each kernel in the logic program and each feature in the feature-labeled images using the kernel activations and the features associated with the feature-labeled images, assigning to each kernel in the logic program the label of the feature with which the kernel has the highest correlation, and applying the assigned kernel labels to the kernels in the rules to obtain kernel-labeled rules.