radioviz.services.image_loader

Image loading service for RadioViz application.

This module provides asynchronous image loading capabilities supporting multiple file formats including TIFF, XYZ, and standard image formats. It implements background thread workers with progress reporting and cancellation support.

Functions

downscale_image(input_image, factor)

Classes

ImageLoaderService()

Service for managing asynchronous image loading operations.

class radioviz.services.image_loader.ImageLoaderService[source]

Bases: QObject

Service for managing asynchronous image loading operations.

This service provides methods to start image loading operations in background threads, track their progress, and handle completion or failure events. It supports cancellation of ongoing operations and manages the lifecycle of worker threads.

See also

_ImageLoaderWorker for the internal worker implementation

Initialize the image loader service.

Creates internal data structures to track active workers and canceled operations.

_forward_progress(path: Path, progress: int) → None[source]

Forward progress signal from worker to service observers.

This internal method ensures that progress updates are only forwarded if the operation hasn’t been canceled.

Parameters:

path (Path) – Path to the image file being loaded
progress (int) – Loading progress percentage (0-100)

cancel(path: Path) → None[source]

Cancel an ongoing image loading operation.

If there is an active worker for the specified path, this method will request cancellation of that operation.

Parameters:: path (Path) – Path to the image file whose loading should be cancelled

clean_up(worker: _ImageLoaderWorker) → None[source]

Clean up resources after worker thread finishes.

Removes the worker from tracking structures and schedules it for deletion.

Parameters:: worker (_ImageLoaderWorker) – The worker thread that finished

load(path: Path) → None[source]

Start loading an image in a background thread.

This method creates a new worker thread to load the specified image file asynchronously. Progress updates and completion/failure signals are forwarded through the service’s signals.

Parameters:: path (Path) – Path to the image file to load

image_load_failed

Signal emitted when image loading fails.

Parameters:

path (Path) – Path to the image file that failed to load
exception (Exception) – Exception that occurred during loading

image_loaded

Signal emitted when an image is successfully loaded.

Parameters:

path (Path) – Path to the loaded image file
array (numpy.ndarray) – Loaded image data as numpy array
metadata (dict[str, Any]) – Extracted image metadata

progress

Signal emitted to report loading progress for a specific image.

Parameters:

path (Path) – Path to the image file being loaded
percentage (int) – Loading progress percentage (0-100)

class radioviz.services.image_loader._ImageLoaderWorker(path: Path)[source]

Bases: QThread

Worker thread for loading images asynchronously.

This class handles the actual image loading process in a separate thread, providing progress updates and emitting signals when loading is complete or fails.