PDF to EPUB With Images: How to Preserve Figures, Photos and Diagrams (2026)

One of the most common complaints about PDF to EPUB conversion is images going missing, blurry, or in the wrong place. Here is how the conversion process handles images and what you can do when something goes wrong.

How images are stored in PDFs

PDFs can contain three types of visual content:

• Embedded raster images (JPEG, PNG) — photos, diagrams, figures stored as pixel data at a fixed resolution
• Embedded vector graphics — scalable line art, charts, and illustrations stored as drawing commands rather than pixels
• Page-level image scans — the entire page is a single scanned photograph; text is not stored as characters, only as pixels

Each type is handled differently during conversion.

What happens to images during conversion

Embedded raster images

toolkit.bot extracts each embedded image at its original resolution and packages it into the EPUB. Images that appear on the page are placed in the EPUB near the surrounding text. The quality of extracted images is exactly the quality stored in the PDF — if the PDF was exported at 150 dpi, the EPUB will have 150 dpi images.

Vector graphics

Simple vector graphics are converted to SVG for crisp rendering at any zoom level. Complex vector graphics (such as charts created in Adobe Illustrator) are rasterised at high resolution to ensure compatibility with all e-readers.

Full-page scans

When the entire page is a scan, toolkit.bot applies OCR to extract the text. Distinct figure regions within the scan are identified and preserved as image elements in the EPUB, placed at the location where they appeared on the original page.

Common image problems and solutions

Images are missing from the EPUB

Most likely cause: the "images" in the PDF are actually decorative vector backgrounds or the PDF was created with image export disabled. Check the original PDF in a viewer — if you cannot right-click and save an image, the content is probably not a standard embedded image. For scanned PDFs, make sure the file has not been flattened in a way that merges text and figures into indistinguishable content.

Images are blurry

The source PDF contains low-resolution images. This is common with PDFs exported from presentations, older scientific articles, or documents scanned at low DPI. toolkit.bot preserves image quality exactly — it cannot improve resolution that was not there in the source. The solution is to obtain a higher-resolution PDF if one exists.

Images appear in the wrong order

In academic PDFs with complex layouts (figures at the top or bottom of columns, spanning both columns), the reading order in the PDF does not always match the visual order. toolkit.bot uses content-stream ordering to place images as close to their original context as possible, but floating figures may appear slightly before or after the paragraph that references them.

Tables are converted to images instead of text

If a table in the PDF is stored as a raster image (common in scanned documents and some older academic papers), it cannot be extracted as an HTML table. It will appear as an image in the EPUB. For text-based PDFs, toolkit.bot attempts to detect and reformat tables as HTML tables for better accessibility and reflow.

Tips for better image results

• Use the highest-quality PDF available — publisher PDFs typically have better embedded images than preprint versions
• Avoid compressed or reduced PDFs — "reduced file size" PDFs often degrade image quality before you convert
• Check the page count matches — if the EPUB has fewer pages than expected, some pages may be full-page images that need OCR treatment
• For image-heavy PDFs — consider whether the EPUB format is the right target; for photo books and heavily visual content, PDF may remain the better format

Frequently asked questions

Do images survive PDF to EPUB conversion?

Yes, in most cases. toolkit.bot extracts all images embedded in the PDF and places them in the EPUB at their original resolution. Vector graphics are preserved as scalable SVG where possible. Raster images (JPEG, PNG) are kept at their original quality.

Why are images missing from my converted EPUB?

The most common cause is that the images in the PDF are actually parts of a large background or page scan rather than separate embedded image objects. When the entire page is a scanned image, OCR is needed to extract the text, and figure images must be extracted from the scan — which requires more advanced processing.

Why do my images look blurry in the EPUB?

The source PDF contains low-resolution images (e.g. 72 dpi). toolkit.bot preserves image quality but cannot upscale raster images beyond their original resolution. If the PDF was exported at screen resolution, the images will look blurry on a Retina or high-DPI e-reader screen.

What happens to figures in two-column academic PDFs?

toolkit.bot detects two-column layout and reflows text into a single column. Figures that span both columns are extracted as full-width images in the EPUB. Figures that appear within one column are placed inline after the surrounding text.

Can I convert a PDF with lots of diagrams and keep them in the right place?

Yes. toolkit.bot uses position-aware extraction to place images near the text that references them. For PDFs where figures are tightly bound to surrounding content (like textbooks), the output generally matches the original reading order.