peal.data.datasets.Image2ClassDataset

class peal.data.datasets.Image2ClassDataset

Bases: ImageDataset

ImageFolder-style dataset: one sub-directory per class.

Class names are the sorted directory names under <root_dir>/<config.x_selection> and the class index is the position in that list. All (class, file) pairs are shuffled with seed 0 and split by config.split into train/val/test. Masks, if config.has_hints, are expected under <root_dir>/masks/[<class>/] and must exist for every image. config.class_ratios subsamples the split to fixed class proportions.

Parameters:

• mode (str) – Split: "train", "val" or "test"; anything else keeps all.

• config (DataConfig) – Uses dataset_path, x_selection, split, has_hints, input_size, output_size, class_ratios and in_memory.

• root_dir (str, optional) – Dataset root; falls back to data_dir and then config.dataset_path. config.dataset_path is rewritten to it.

• data_dir (str, optional) – Alternative spelling of root_dir.

• transform (callable, optional) – Applied to image and mask (same RNG state). Defaults to ToTensor().

• task_config (TaskConfig, optional) – Only its presence matters (for class_ratios balancing).

• return_dict (bool, optional) – Return a dict from __getitem__ instead of (x, y...).

Variables:

• idx_to_name (list of str) – Class index to directory name.

• urls (list of tuple) – (class_name, filename) of the current split/restriction.

Methods

class_idx_to_name	Return the directory name of class class_idx.
disable_class_restriction	Restore backup_urls and clear the restriction flag.
disable_groups	Stop returning has_confounder.
disable_hints	Stop returning masks and restore the full urls list.
disable_idx	Stop returning the sample index.
disable_string_description	Stop returning the description.
disable_tokens	Drop the tokenizer and restore the previous description setting.
disable_url	Stop returning the filename.
enable_class_restriction	Keep only samples of the given class(es); the full list goes to backup_urls.
enable_groups	Also return has_confounder (always 0 unless a subclass overrides it).
enable_hints	Return masks as mask and restrict urls to samples that have one.
enable_idx	Also return the sample index.
enable_string_description	Also return the class directory name as description.
enable_tokens	Also return tokens: the description tokenized with tokenizer.
enable_url	Also return the filename as url.
has_confounder	Confounder presence for a file; placeholder returning 0.
load_in_memory	Cache all images (and masks, if has_hints) of the split as arrays.
set_task_specific_urls	Subsample urls so the classes follow config.class_ratios.

Attributes

output_size

Number of classes from config.output_size (int or one-element list).

__init__(mode, config, root_dir=None, data_dir=None, transform=torchvision.transforms.ToTensor, task_config=None, return_dict=False)

Scan the class directories, split them and optionally cache images.

load_in_memory()

Cache all images (and masks, if has_hints) of the split as arrays.

class_idx_to_name(class_idx)

Return the directory name of class class_idx.

enable_hints()

Return masks as mask and restrict urls to samples that have one.

disable_hints()

Stop returning masks and restore the full urls list.

enable_string_description()

Also return the class directory name as description.

disable_string_description()

Stop returning the description.

enable_tokens(tokenizer)

Also return tokens: the description tokenized with tokenizer.

Parameters:

tokenizer (callable) – HuggingFace-style tokenizer with model_max_length.

disable_tokens()

Drop the tokenizer and restore the previous description setting.

enable_idx()

Also return the sample index.

disable_idx()

Stop returning the sample index.

enable_url()

Also return the filename as url.

disable_url()

Stop returning the filename.

property output_size

Number of classes from config.output_size (int or one-element list).

set_task_specific_urls()

Subsample urls so the classes follow config.class_ratios.

Same scheme as Image2MixedDataset.set_task_specific_keys; the original list is saved in urls_backup.

enable_class_restriction(class_idx)

Keep only samples of the given class(es); the full list goes to backup_urls.

Parameters:

class_idx (int or list of int) – Class index or indices to keep.

disable_class_restriction()

Restore backup_urls and clear the restriction flag.

enable_groups()

Also return has_confounder (always 0 unless a subclass overrides it).

disable_groups()

Stop returning has_confounder.

has_confounder(filename)

Confounder presence for a file; placeholder returning 0.

Subclasses that know their confounder override this. The base implementation prints a warning.

Parameters:

filename (str) – Image filename.

Returns:

Always 0.

Return type:

int