Analyze PPTX

Analyze PPTX Format & Style

Overview

Extract format, colors, fonts, sizes, shapes, and layout from .pptx files by unzipping and parsing the internal XML structure. No external dependencies needed.

When to Use

• User wants to understand a PPT's visual style/design preferences
• Need to replicate a PPT's color scheme or format in another context (e.g., HTML slides, LaTeX)
• Comparing design styles across presentations
• Extracting a "style profile" before creating new slides matching an existing deck

Core Technique

.pptx is a ZIP archive containing XML files. Unzip and parse the XML to extract all styling data.

Step 1: Unzip

mkdir -p /tmp/pptx_extracted
unzip -o "file.pptx" -d /tmp/pptx_extracted

Step 2: Identify Structure

Key files:

ppt/slides/slide{N}.xml          # Slide content, shapes, inline styles
ppt/slides/_rels/slide{N}.xml.rels  # Image/layout references per slide
ppt/slideLayouts/slideLayout{N}.xml # Layout templates
ppt/slideMasters/slideMaster{N}.xml # Master slide definitions
ppt/theme/theme{N}.xml           # Theme color palette & font scheme
ppt/media/                       # Embedded images
ppt/presentation.xml             # Slide dimensions, slide order

To find which theme a slide uses, follow the chain:

slide → _rels → slideLayout → _rels → slideMaster → _rels → theme

Step 3: Extract Colors

The XML is often single-line. Use sed to split before grepping:

# Explicit RGB colors (most important - these are custom overrides)
cat ppt/slides/slide1.xml | sed 's/>/>\n/g' | \
  grep -o 'srgbClr val="[0-9A-Fa-f]*"' | sort | uniq -c | sort -rn

# Theme color references (mapped to theme palette)
cat ppt/slides/slide1.xml | sed 's/>/>\n/g' | \
  grep -o 'schemeClr val="[a-zA-Z0-9]*"' | sort | uniq -c | sort -rn

Step 4: Extract Theme Color Palette

# Get full color scheme from theme file
cat ppt/theme/theme{N}.xml | sed 's/>/>\n/g' | \
  sed -n '/a:clrScheme/,/\/a:clrScheme/p'

Theme color mapping:

Step 5: Extract Fonts

# Latin (Western) fonts
cat ppt/slides/slide1.xml | sed 's/>/>\n/g' | \
  grep -o 'latin typeface="[^"]*"' | sort | uniq -c | sort -rn

# East Asian fonts (Chinese/Japanese/Korean)
cat ppt/slides/slide1.xml | sed 's/>/>\n/g' | \
  grep -o 'ea typeface="[^"]*"' | sort | uniq -c | sort -rn

Font reference values:

• +mj-lt / +mj-ea = Major (heading) font from theme
• +mn-lt / +mn-ea = Minor (body) font from theme
• Explicit name (e.g., 微软雅黑) = Custom override

Step 6: Extract Font Sizes

cat ppt/slides/slide1.xml | sed 's/>/>\n/g' | \
  grep -o 'sz="[0-9]*"' | sort | uniq -c | sort -rn

Size values are in hundredths of a point: 1200 = 12pt, 3200 = 32pt.

Step 7: Extract Shapes & Layout

# Shape types
cat ppt/slides/slide1.xml | sed 's/>/>\n/g' | \
  grep -E 'prstGeom|custGeom' | grep -o 'prst="[^"]*"' | sort | uniq -c | sort -rn

# Count total shapes
cat ppt/slides/slide1.xml | sed 's/>/>\n/g' | grep -c '<p:sp'

# Count images
cat ppt/slides/slide1.xml | sed 's/>/>\n/g' | grep -c 'blipFill'

# Line widths (in EMUs: 12700 = 1pt)
cat ppt/slides/slide1.xml | sed 's/>/>\n/g' | \
  grep -o 'ln w="[0-9]*"' | sort | uniq -c | sort -rn

Step 8: Extract Text Content

cat ppt/slides/slide1.xml | sed 's/</\n</g' | \
  grep 'a:t>' | sed 's/.*<a:t>//; s/<\/a:t.*//'

Output Format

Present analysis as a structured report:

1. Color Palette - Table with HEX, swatch description, usage frequency, inferred role
2. Theme Colors - Mapped accent/text/background colors
3. Fonts - Primary fonts for Latin and CJK, with frequency
4. Font Sizes - Distribution indicating content density style
5. Layout - Shape count, types, images, structural pattern
6. Style Summary - Table summarizing overall design personality (dense vs. sparse, formal vs. casual, color mood)

Common Pitfalls

• macOS grep lacks -P flag — use sed 's/>/>\n/g' to split XML then pipe to basic grep -o
• Single-line XML — always split before grepping; raw XML is typically one giant line
• Theme indirection — slide colors referencing schemeClr need theme file lookup to get actual HEX
• Multiple themes — large decks may have many theme files; follow the rels chain per slide
• EMU units — positions/sizes in XML are in EMUs (914400 EMU = 1 inch)