给九种印度文字造字体,不再从零画,而是给现成字体换皮
造一款印度文字的字体,难点不在画字母,而在连字:几百上千种组合(辅音连写、半形、元音变体)必须彼此咬合,OpenType 排版引擎才能正确拼出每个词。Srijika 换了个思路:不从头生成,而是拿一套已经排版完整的字体当模板,只重画字形轮廓,把模板的字符映射和排版规则原样保留。结果就是 66 款字体全部通过 OpenType 校验,在 HarfBuzz 和 CoreText 上复现了模板的排版序列。但论文自己承认:在 56 款字体的风格迁移测试里,直接复制模板反而赢了 50 款,所谓风格迁移的效果只有用自家模型才能测出来。也就是说,这套系统真正可靠的价值是「换皮不换骨」——保证字体能用、排版不错,但风格创新还没被证明。
📄 原文摘要(英文)
We present Srijika, a system for producing installable OpenType fonts for nine Brahmic scripts: Devanagari, Tamil, Bengali, Telugu, Kannada, Malayalam, Gujarati, Gurmukhi, and Odia. Rather than generating fonts from scratch, Srijika restyles glyph outlines from shaping-complete template fonts. It preserves the template's cmap and GSUB closure and its GPOS data under a documented metric policy, making every output a complete font by construction. This addresses a central challenge of Indic font generation: hundreds to thousands of conjuncts, half forms, and matra variants must remain mutually consistent under OpenType shaping. Srijika produces 66 TTFs: 57 curated presets and nine open-vocabulary showcase fonts. All pass the OpenType Sanitizer, while HarfBuzz and CoreText reproduce the template glyph-ID sequences on conjunct-heavy probes. A full-closure audit covering 80,915 glyphs and 54,812 anchors quantifies metric changes. Natural-language style selection uses Lipika, a retrieval index over approximately 650 open-license font families. A reference-conditioned latent diffusion model redraws template glyphs in the selected style, followed by content gating, harmonization, and shaped-cluster verification with fallback to template outlines. We evaluate against no-learning baselines. On diffusion-training-family-held-out SSIM gates, template copying outperforms generation on 50 of 56 faces. Style movement is measurable only with an internal same-model embedding whose training corpus includes the held-out families, so these results require caution. A learned baseline, independent style metric, and human study are outside this report's scope. Our contributions are the layout-reusing formulation and pipeline, its nine-script audit and benchmark, and a negative-results catalogue covering failed conditioning, objective choices, and data-hull limits of reference-guided restyling.