Procedural Fractals as Multi-Scale Targets for Evaluating Rasterization Fidelity

Procedural fractals provide reproducible multi-scale structures that can serve as controlled targets for evaluating resolution-dependent changes introduced during rasterization. This study investigated the effects of rasterization resolution on geometric, spectral, high-frequency, and structural image properties using fifteen procedurally generated PostScript fractals rasterized at 150, 300, 600, and 1200 DPI, with 1200 DPI used as an operational high-resolution reference. Rasterization fidelity was quantified using fractal-dimension deviation (ΔD), power spectral density slope deviation (Δβ), high-frequency energy ratio (EHF), and multi-scale averaged structural similarity (QMS). Increasing resolution significantly reduced ΔD and Δβ (p < 0.001), while EHF decreased systematically across all four resolutions (p < 0.001). QMS was already high at 150 DPI (0.9667 ± 0.0188) and increased to 0.9931 ± 0.0058 at 600 DPI (p < 0.001). Expected monotonic trajectories were observed for 12/15 fractals for ΔD, 14/15 for Δβ, and 15/15 for both EHF and QMS. These findings show that high structural similarity can coexist with measurable resolution-dependent differences in scale-sensitive geometric and spectral properties, supporting procedural fractals as reproducible candidate multi-scale targets for evaluating rasterization fidelity.