scripts.data_preparation.extract_subimages

scripts.data_preparation.extract_subimages.extract_subimages(opt)

Crop images to subimages.

Parameters:

• opt (dict) – Configuration dict. It contains:

• input_folder (str) – Path to the input folder.

• save_folder (str) – Path to save folder.

• n_thread (int) – Thread number.

scripts.data_preparation.extract_subimages.main()

A multi-thread tool to crop large images to sub-images for faster IO.

It is used for DIV2K dataset.

Parameters:

• opt (dict) – Configuration dict. It contains:

• n_thread (int) – Thread number.

• compression_level (int) – CV_IMWRITE_PNG_COMPRESSION from 0 to 9. A higher value means a smaller size and longer compression time. Use 0 for faster CPU decompression. Default: 3, same in cv2.

• input_folder (str) – Path to the input folder.

• save_folder (str) – Path to save folder.

• crop_size (int) – Crop size.

• step (int) – Step for overlapped sliding window.

• thresh_size (int) – Threshold size. Patches whose size is lower than thresh_size will be dropped.

Usage:

For each folder, run this script. Typically, there are four folders to be processed for DIV2K dataset.

• DIV2K_train_HR

• DIV2K_train_LR_bicubic/X2

• DIV2K_train_LR_bicubic/X3

• DIV2K_train_LR_bicubic/X4

After process, each sub_folder should have the same number of subimages.

Remember to modify opt configurations according to your settings.

scripts.data_preparation.extract_subimages.worker(path, opt)

Worker for each process.

Parameters:

• path (str) – Image path.

• opt (dict) – Configuration dict. It contains:

• crop_size (int) – Crop size.

• step (int) – Step for overlapped sliding window.

• thresh_size (int) – Threshold size. Patches whose size is lower than thresh_size will be dropped.

• save_folder (str) – Path to save folder.

• compression_level (int) – for cv2.IMWRITE_PNG_COMPRESSION.

Returns:

Process information displayed in progress bar.

Return type:

process_info (str)