Single Frame Loader
The singleFrameLoader module is a custom DICOM loader designed to cache and render a single frame buffer with its metadata. It enables efficient retrieval and display of single-frame images extracted from multi-frame DICOM objects.
Key Responsibilities
- Caches pixel data and metadata for quick access: Stores pixel data and metadata for single-frame images in an internal cache to optimize performance.
- Converts RGB to RGBA format for rendering: Converts RGB pixel data to RGBA format for compatibility with Cornerstone rendering.
- Clears cached frames to free memory: Removes cached frames from memory to prevent memory leaks and optimize performance.
- Creates custom image objects for rendering: Generates Cornerstone-compatible image objects for rendering single-frame images.
Internal Workflow
- Metadata Conversion:
- Metadata for the single frame is converted and stored in the Image Manager.
- Image ID Management:
- Custom image IDs are generated for each single frame.
- Frame Caching:
- Single frames are cached to avoid subsequent requests.
- Custom Image Creation:
- The single frame is processed into a Cornerstone-compatible image object, including pixel data extraction and scaling.
- Memory Management:
- Cached frames are cleared from memory to optimize performance and prevent memory leaks.
Main Functions
setSingleFrameCache
Syntax:
setSingleFrameCache(data: Uint8ClampedArray, metadata: Metadata): ImageObject
Parameters:
| Parameter | Type | Description |
|---|---|---|
data | Uint8ClampedArray | The pixel data for the single frame. |
metadata | Metadata | The metadata object. |
Returns:
ImageObject – An object containing the ID of the cached single frame, its metadata and its SOP Instance UID.
clearSingleFrameCache
Syntax:
clearSingleFrameCache(imageId?: string): void
Parameters:
| Parameter | Type | Description |
|---|---|---|
imageId | string | Optional ID of the single frame to be cleared. |
Returns:
void – Clears the cached single frame from memory. If no ID is provided, all cached frames are cleared.
loadSingleFrameImage
Syntax:
loadSingleFrameImage(imageId: string): ImageLoadObject
Parameters:
| Parameter | Type | Description |
|---|---|---|
imageId | string | The ID of the image/frame to be loaded. |
Returns:
ImageLoadObject – An object containing a Promise that resolves to the loaded image.
