PDFMove

Blog

Guides, tips and comparisons on processing PDFs, images, audio and video.

How-To

How to Extract Embedded Images from a PDF in Their Raw Form

Extracting the images inside a PDF as a ZIP in their original state: how it differs from taking a page image, split images, the mask problem, and interpreting the extracted files.

7 min read

Guide

How Are Images Stored in a PDF? XObjects, Filters and Masks

PDF's image storage structure: Image XObject objects, DCTDecode/FlateDecode filters, color spaces, transparency masks, and why images get split into pieces.

8 min read

How-To

How to Optimize a PDF for the Web (Linearize)

Restructuring a PDF for fast web view: what linearization is, who benefits, its effect on file size, and how it differs from compression.

7 min read

How-To

How to Add Text and Shapes to a PDF

Editing PDFs in the browser: adding text boxes, drawing, placing a signature, font and positioning settings, and the checks to make before saving.

7 min read

Comparison

Convert a PDF to SVG or PNG? Vector vs. Raster Compared

The differences between exporting a PDF page as SVG, PNG or JPEG: file size, scalability, editability, and which wins for which content type.

7 min read

How-To

How to Convert a PDF to SVG: A Vector Export Guide

Exporting PDF pages to vector SVG: the font problem, choosing between text and outlines, behavior with multi-page documents, and what gets lost in the conversion.

7 min read

How-To

How to Extract Pages from a PDF: A Range Selection Guide

The steps for extracting specific pages as a new PDF: writing ranges, cover page offset, selecting multiple ranges, and what's preserved and lost in the extracted file.

7 min read

Guide

How Does PDF Page Extraction Work? The Object Tree and Shared Resources

The background of page extraction: PDF's page tree structure, shared resources, why the extracted file can stay large, and what happens to bookmarks and links.

7 min read

Guide

What Is a PDF Overlay? Content Streams and Layer Logic

What the overlay operation corresponds to inside the file: XObject form objects, appending to the content stream, drawing order, transparency groups, and how resource collisions are resolved.

8 min read

Guide

What Is PDF Metadata? The Difference Between XMP and the Document Info Dictionary

The two-layer structure of PDF metadata: the Document Info dictionary, the XMP packet, conflicts between them, PDF/A requirements, and what metadata means for privacy.

7 min read

How-To

How to Edit and Clean PDF Metadata

Viewing, changing and deleting PDF metadata: the title/author/keyword fields, privacy risks, the difference between XMP and document info, and a pre-sharing checklist.

7 min read

Comparison

Rescuing PDF Content: Markdown, Word, or Plain Text?

The target formats for making PDF content reusable compared: Markdown, Word, plain text and HTML. Which is right for which purpose.

7 min read

How-To

How to Convert a PDF to Markdown: Preserving Headings and Structure

Getting PDF content into Markdown: heading hierarchy detection, lists, tables, links, the multi-column layout problem, and post-conversion cleanup steps.

7 min read

How-To

How to Flatten a PDF Form

Turning filled form fields and annotations into fixed content: why it's needed, which elements are affected, what to watch on signed documents, and a post-flattening checklist.

7 min read

Guide

How Do PDF Form Fields Work? AcroForm, Appearance Streams and Flattening

The technical structure of PDF forms: the AcroForm dictionary, widget annotations, appearance streams, the NeedAppearances flag, and what flattening changes in the file.

7 min read

Comparison

Editing a PDF: A Browser Tool, a Desktop Program, or Converting to Word?

Three ways to change a PDF compared: browser-based layer adding, desktop PDF editors, and converting to Word and saving back. Which is right for which job.

7 min read

Guide

Why Isn't Editing a PDF Like Editing in Word? The Format's Technical Logic

Why text can't be edited in place in a PDF, how page content is stored, the difference between adding a layer and real editing, and the limits of browser-based editors.

7 min read

How-To

How to Add a Letterhead or Stamp with PDF Overlay

Overlaying one PDF onto another: applying letterhead paper, stamping, page alignment, size mismatches, and deciding between background and foreground layering.

7 min read

Comparison

Ways to Add a Letterhead: Overlay, Watermark, or a Word Template?

Three methods for adding a corporate letterhead, logo or stamp to a PDF compared: an overlay tool, a watermark tool, and using a template in the source document.

7 min read

Guide

Font and Page Logic in Office to PDF Conversion

Moving from a flow document model to a fixed page model: font metrics, line-breaking math, Excel's lack of a page concept, and PowerPoint becoming static.

8 min read

Comparison

Office to PDF: From Inside the Program, an Online Tool, or the Print Menu?

Three ways to convert Word, Excel and PowerPoint files to PDF compared: Office's own export, an online converter, and the 'Print to PDF' option.

7 min read

How-To

How to Convert a Word, Excel or PowerPoint File to PDF

Converting Office files to PDF: font embedding, fitting Excel to the page, losing PowerPoint animations, link and form behavior, and post-conversion checks.

7 min read

How-To

N-up: How to Combine Multiple PDF Pages onto One Sheet

2-up, 4-up and 6-up layouts: how many pages fit on a sheet, the legibility limit, choosing landscape or portrait orientation, and the paper-saving math.

6 min read

Guide

What Is N-up? The Logic of Page Imposition and the Scaling Math

The background of the N-up operation: how the scale factor is calculated, what happens when aspect ratios don't match, the difference between N-up and booklet layout, and the effect on file size.

7 min read