关于缩减.ttf字体文件大小以降低PDFJet生成PDF体积及进一步压缩精简后字体的技术咨询

Hey there! Since you’ve already stripped out unused glyphs from your TTF file, we need to dive into more targeted optimizations to squeeze out extra size—let’s break down actionable steps you can take:

1. Deep Cleanup in FontForge (Beyond Basic Steps) #

You mentioned trying FontForge’s built-in tools, but let’s go a layer deeper:

• Strip redundant metadata: Head to Element > Font Info > General and trim any unnecessary fields (like extra designer notes, redundant copyright text, or unused font names). Even small bits of metadata add up.
• Batch-process glyph optimizations: Instead of tweaking individual glyphs, select all glyphs (Edit > Select > Select All), then run Element > Clean Up > Remove Overlaps (ensure this applies to every glyph). Follow this with Element > Simplify—adjust the threshold slowly (start with 1-2) to reduce anchor points without distorting your glyphs.
• Remove unused OpenType tables: If your font doesn’t need advanced typographic features (ligatures, kerning, stylistic alternates), when generating the font (File > Generate Fonts), uncheck options for GSUB, GPOS, and GDEF tables. These tables often take up surprising space even if you don’t use their features.

2. Use Specialized Font Compression Tools #

FontForge is great for visual edits, but dedicated tools are better for low-level compression:

• ttfsubset (from FontTools): This tool lets you double down on glyph subsetting and table stripping. Run a command like this (adjust the Unicode range to match exactly what you need):

  ttfsubset your-font.ttf --unicodes="U+0020-007E,U+00A0" --no-hinting --no-subset-tables+=GSUB,GPOS,GDEF
  

  The --no-hinting flag is especially useful if you’re only using the font for PDF generation (PDF renderers usually ignore hinting data, which can save 10-30% of file size).
• ttfoptimize (also from FontTools): Automatically cleans up redundant glyph data, compresses table structures, and removes unused elements. Run:

  ttfoptimize your-font.ttf optimized-font.ttf
  

3. Ditch Unnecessary Hinting Data #

If your font is only intended for PDF output (not screen display), hinting is completely unnecessary. In FontForge:

• Go to Element > Font Info > Hinting and set hinting mode to None.
• Regenerate the font—this alone can cut down size significantly if the original font had complex hinting tables.

4. Remove Duplicate Glyphs #

Even after manual cleanup, there might be duplicate glyphs hiding (e.g., same shape mapped to different Unicode codes). In FontForge:

• Use Edit > Select > Select Duplicate Glyphs to find duplicates.
• Delete the redundant ones and keep only one reference to the glyph shape.

After trying these steps, you should see a noticeable drop in file size—especially if you combine FontForge cleanup with the FontTools command-line tools.

备注：内容来源于stack exchange，提问作者Vipul Aggarwal