Images to PDF

New in 1.13.0.

ImageToPdf puts images into a PDF, one per page, such as scanned receipts, photos or drawings for an archive. It reads PNG, JPEG, GIF, WebP, BMP and TIFF (the first frame of an animated GIF or a multi-page TIFF).

// Each page the size of its image
byte[] pdf = ImageToPdf.Convert(new[] { File.ReadAllBytes("scan-1.jpg"), File.ReadAllBytes("scan-2.png") });

// Files in, file out
ImageToPdf.ConvertFiles(new[] { "receipt-1.jpg", "receipt-2.jpg" }, "receipts.pdf");

// A4 pages with margins, each image centred and scaled down to fit, as PDF/A for archiving
byte[] archive = ImageToPdf.Convert(scans,
    new PdfOptions { PageSize = PageSize.A4, Conformance = PdfConformance.PdfA2b, Title = "Receipts 2026" },
    new ImageToPdfOptions { FitPageToImage = false });

Page size

By default every page is exactly the size of its image, with no margins. ImageToPdfOptions.Dpi (default 96, one image pixel per CSS pixel) sets the printed size: a scan 2,480 pixels wide at 300 dpi becomes an A4-wide page.

With FitPageToImage = false every page has the PdfOptions page size and margins. Each image is centred, and scaled down to fit when it is larger than the space inside the margins; smaller images keep their size.

Output settings

The PdfOptions work as for HTML to PDF: metadata, PDF/A, passwords and watermarks, and a fixed CreationDate for byte-identical output. JPEG images are embedded as they are, without re-encoding.

Errors

An empty list or more than ImageToPdf.MaxImages (10,000) images throws ArgumentException, as does a Dpi that is not a positive number. An image that is not in a supported format or is damaged throws InvalidDataException naming its position ("Image 2 ..."), and more images than PdfOptions.MaxPages throws PdfLimitException. An overload takes a cancellation token.