Multilabel classification assigns each input multiple labels from a shared set. Unlike single-label classification, an input can belong to several categories, and the number of labels may vary. section 4.0
Image tagging
An image containing both a cat and a dog receives both the “cat” and “dog” labels. Image classification systems can similarly tag every category present in an image. section 4.0 section 11.1
The distinction depends on whether categories are exclusive. Reuters wires assigned one topic illustrate single-label multiclass classification; allowing several topics would make the task multilabel multiclass classification. section 4.2
Figure 11.1 The three main computer vision tasks: classification, segmentation, and detection
Compare multilabel image classification with segmentation and object detection: classification assigns labels, segmentation partitions pixels, and detection adds bounding boxes. section 11.1


