Module image_compare 

Image comparison utilities for cross-renderer parity tests.

Provides lightweight pixel-level comparison metrics without pulling in external image-comparison crates. Used by the headless comparison test harness to assert that WGPU and Bevy renderers produce structurally equivalent output for the same FrameOutput.

Functions

compute_rmse

Per-pixel RMSE (Root Mean Square Error) between two RGBA8 images.

count_differing_pixels

Count the number of pixels where any RGBA channel differs by more than threshold (0-255).

differing_pixel_fraction

Fraction of pixels that differ (0.0 to 1.0).