Structure-Aware Pixel Art Scaling via Block Size Detection

Abstract

Standard interpolation methods degrade pixel art through blurring or geometric distortion. We propose a lossless scaling algorithm that detects the intrinsic block size to normalize the image grid, thereby expanding the set of valid scaling factors beyond standard integer multiples. This approach enables precise, distortion-free resizing closer to user-specified scales. To validate this approach, we introduce a novel evaluation framework consisting of Color Loss (CL), Block Size Consistency (BSC), and reversibility (REV) tests. Experimental results demonstrate that the proposed method maintains the original palette and grid structure without introducing interpolation artifacts. Furthermore, the reversibility tests confirm that the scaling process remains mathematically lossless, ensuring the genre's structural and chromatic integrity.