nexusLIMS.extractors.plugins.preview_generators.image_preview#

Image file preview generator.

Module Contents#

Classes#

ImagePreviewGenerator

Preview generator for standard image files.

Functions#

image_to_square_thumbnail

Generate a preview thumbnail from a non-data image file.

down_sample_image

Load an image file from disk, down-sample it to the requested dpi, and save.

API#

nexusLIMS.extractors.plugins.preview_generators.image_preview.image_to_square_thumbnail(f: Path, out_path: Path, output_size: int) → bool[source]#

Generate a preview thumbnail from a non-data image file.

Images of common filetypes will be transformed into 500 x 500 pixel images by first scaling the largest dimension to 500 pixels and then padding the resulting image to square.

Parameters:

  • f – The string of the path of an image file for which a thumbnail should be generated.

  • out_path – A path to the desired thumbnail filename. All formats supported by save() can be used.

  • output_size – The desired resulting size of the thumbnail image.

Returns:

Whether a preview was generated

Return type:

bool

nexusLIMS.extractors.plugins.preview_generators.image_preview.down_sample_image(fname: Path, out_path: Path, output_size: Tuple[int, int] | None = None, factor: int | None = None)[source]#

Load an image file from disk, down-sample it to the requested dpi, and save.

Sometimes the data doesn’t need to be loaded as a HyperSpy signal, and it’s better just to down-sample existing image data (such as for .tif files created by the Quanta SEM).

Parameters:

  • fname – The filepath that will be resized. All formats supported by PIL.Image.open() can be used

  • out_path – A path to the desired thumbnail filename. All formats supported by PIL.Image.Image.save() can be used.

  • output_size – A tuple of ints specifying the width and height of the output image. Either this argument or factor should be provided (not both).

  • factor – The multiple of the image size to reduce by (i.e. a value of 2 results in an image that is 50% of each original dimension). Either this argument or output_size should be provided (not both).

class nexusLIMS.extractors.plugins.preview_generators.image_preview.ImagePreviewGenerator[source]#

Preview generator for standard image files.

This generator creates square thumbnail previews from image files (PNG, JPEG, TIFF, BMP, GIF) using PIL/Pillow.

name#

‘image_preview’

priority#

100

supported_extensions#

Type: typing.ClassVar

supports(context: ExtractionContext) → bool[source]#

Check if this generator supports the given file.

Parameters:

context – The extraction context containing file information

Returns:

True if file extension is a supported image format

Return type:

bool

generate(context: ExtractionContext, output_path: Path) → bool[source]#

Generate a square thumbnail preview from an image file.

Parameters:

  • context – The extraction context containing file information

  • output_path – Path where the preview image should be saved

Returns:

True if preview was successfully generated, False otherwise

Return type:

bool