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Why Can a Converted PDF Image Look Blurry? (And How to Fix It)

Fix blurry text and low-resolution graphics when converting PDF pages to JPG or PNG. Understand DPI, canvas scaling, and rasterization settings.

Quick Summary

Converted PDF images look blurry when rasterized at standard 72 DPI screen resolution instead of 150 or 300 DPI, or when converted to heavily compressed lossy JPEG. To fix this, convert to lossless PNG or use our PDF to PNG tool with high-DPI supersampling enabled.

Why Converted PDF Images Lose Sharpness

When a vector PDF document is turned into a static image file, mathematical lines and Bézier curves are "rasterized" into a fixed grid of pixels:

  1. Low Default DPI (72 DPI): Many basic conversion tools default to 72 DPI (Standard Web Resolution from 1990). On a modern 4K monitor or smartphone screen, 72 DPI looks noticeably pixelated.
  2. Aggressive JPEG Compression: Overly aggressive lossy compression blurs the boundaries between black characters and white background pixels.
  3. Improper Viewport Scaling: Converting pages without factoring in high-density device pixel ratios (Retina / 2x / 3x screens).

    4. How to Get Crisp, High-Res Converted Images

    1. Use PDF to PNG Instead of Low-Quality JPG: Use our PDF to PNG tool, which uses lossless compression and preserves sharp character edges.
    2. Verify Original PDF Quality: Check if the original PDF was scanned from a physical paper at low resolution. If the source scan was 100 DPI, conversion cannot invent missing details.
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