Fix: Resolves memory leak caused by using CRAFT detector repeatedly

[daniellovera]

This fix enables garbage collection to appropriately work when

CRAFT-pytorch/test.py

Line 69 in e332dd8

def test_net(net, image, text_threshold, link_threshold, low_text, cuda, poly, refine_net=None):

returns, by deleting x we moved to the GPU after we move the forward pass results back to the CPU. Likewise, the same in deleting y and feature after they are no longer needed.

See https://pytorch.org/blog/understanding-gpu-memory-2/#why-doesnt-automatic-garbage-collection-work for more detail.

Running torch.cuda.empty_cache() in test_net() before returning allows nvidia-smi to be accurate.

Relevant package versions
torch version 2.2.1+cu121
torchvision 0.17.1+cu121

Hope this helps!