Raster vs Vector in PDFs

Overview

PDFs routinely mix two graphic languages. Raster (bitmap) content stores a grid of pixels—photos, scans, and many screenshots. Vector content stores paths, text, and shapes that can scale cleanly—logos, rules, and most born-digital type.

Problems appear when workflows ignore which is which. Enlarging a raster logo makes pixels obvious. Flattening a vector illustration to a low-resolution image during export destroys sharpness that the PDF could have kept. Conversely, leaving a huge uncompressed photograph as a full-page image can make an otherwise light vector document enormous.

Dockzio tools map cleanly onto these jobs: pdf-to-jpg and pdf-extract-images work in the raster world; convert-image helps change raster formats; vector text and logos are best preserved by avoiding unnecessary rasterization in the first place.

Step-by-step

1. 1. Identify what kind of content you are dealing with

   Zoom far in on edges. Vectors stay sharp; rasters reveal pixels or JPEG ringing. Textable text you can select is usually real text (vector outlines + font data), not OCR’d pixels—though OCR can blur that distinction.

   In production handoffs, ask whether logos were placed as AI/SVG/PDF vectors or as PNG/JPG. The answer predicts how well the job will scale to banners or large-format print.

2. 2. Keep vectors vector until you have a reason not to

   Export design files to PDF with fonts embedded and logos as vectors when the receiving system allows it. Do not “simplify” by converting an entire page to an image unless a downstream process requires it.

   If a printer asks for outlined fonts, that is still vector—just converted from font glyphs to paths. That is different from rasterizing type to pixels.

3. 3. Treat photographs as resolution budgets

   Size raster images to their final printed or on-screen dimensions at an appropriate ppi. Upscaling a 72 ppi web download for a poster does not invent detail.

   When you need page previews or social crops, pdf-to-jpg is appropriate because you intentionally want a raster snapshot of the page.

4. 4. Extract or convert rasters without guessing

   Use pdf-extract-images when you need the embedded image objects themselves (for retouching or compression). That often preserves more fidelity than screenshotting the page.

   Use convert-image when the extracted asset must change format (for example PNG to JPG) before reinsertion into another workflow.

5. 5. Know what flattening will do

   Transparency flattening and some older PDF/X workflows may rasterize complex regions. Inspect flattened output at high zoom for soft type or fragmented images.

   If a page must stay editable as vectors, avoid round-trips through whole-page JPG conversion.

Common mistakes

• Saving a logo from a website and using it for print. Site assets are often small RGB PNGs or JPEGs. Request a vector logo or a high-resolution master from the brand owner.
• Rasterizing text to “be safe”. Turning type into pixels can hide font issues but creates soft edges and kills search/accessibility. Embed fonts or outline only when required.
• Screenshotting instead of extracting. Screenshots resample through the display and often add compression. Extract embedded images when you need the source pixels.