Suppose a model
M classifies apples and oranges. Can
M be extended to classify a third class of objects, e.g., pears, such that the new images for 'retraining' only have pears annotated and apples and oranges ignored? That is, since
M already classifies apples and oranges, can the old weights be somehow preserved and let the retraining focus specifically on learning about pears?
Methods such as fine-tuning and learning without forgetting seem to require all objects in the new images annotated though.