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.

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)