mantidimaging.gui.utility.gif_utils module#

Module containing utility functions for GIF export such as size estimation and optimal frame skip calculation to balance file size and angular resolution.

mantidimaging.gui.utility.gif_utils.calculate_optimal_frame_skip(projection_count: int, image_height: int, image_width: int, angle_count: int | None = None, max_size_mb: float = 5.0) → int[source]#

Calculate optimal frame skip (step size) for GIF export.

Balances the following constraints: - Angular resolution (avoid skipping more than 1 frame per degree) - File size limit (default 5MB)

Parameters:

  • projection_count – Total number of projections in the stack

  • image_height – Height of each image frame (needed for size estimation)

  • image_width – Width of each image frame (needed for size estimation)

  • angle_count – Number of unique angles (if None, assumes num_projections = num_angles)

  • max_size_mb – Maximum GIF file size in MB (default 5.0)

Returns:

Recommended frame_skip value (step size)

mantidimaging.gui.utility.gif_utils.estimate_gif_size(frame_count: int, image_height: int, image_width: int) → float[source]#

Roughly estimate compressed GIF file size in MB.

Tries to empirically derive compression ratio from GIF LZW compression testing with flower imagestack IMAT00010675 (~0.85f).

Duration is excluded from estimation as it has negligible effect on file size.

Parameters:

  • frame_count – Number of frames in the GIF

  • image_height – Height of each frame in pixels

  • image_width – Width of each frame in pixels

Returns:

Estimated file size in MB