Lyo.Pdf.Rendering 1.0.2

Lyo.Pdf.Rendering

Rasterizes PDF pages to PNG via PDFtoImage (PDFium + Skia under the hood; bblanchon.PDFium native packages). Targets net10.0.

Examples

Usage

services.AddPdfPageRasterizer();

public sealed class CoverRenderer(IPdfPageRasterizer rasterizer)
{
    public async Task<byte[]> RenderAsync(ReadOnlyMemory<byte> pdf, CancellationToken ct)
        => (await rasterizer.RenderPageToPngAsync(pdf, pageNumber1Based: 1, dpi: 144, cancellationToken: ct))
            .ValueOrThrow()
            .PngBytes;
}

API

public interface IPdfPageRasterizer
{
    Task<Result<PdfRasterPage>> RenderPageToPngAsync(
        ReadOnlyMemory<byte> pdfBytes,
        int pageNumber1Based,
        int dpi,
        string? password = null,
        CancellationToken cancellationToken = default);
}

public sealed record PdfRasterPage(byte[] PngBytes, int WidthPx, int HeightPx);

API

PdfToImagePageRasterizer is the default implementation: it dispatches the CPU-bound PDFium call through Task.Run, probes the rendered bytes with ImageSharp to read the bitmap dimensions, and logs an elapsed-ms trace on success. Failures surface as Result<PdfRasterPage>.Failure tagged with:

• PdfRenderErrorCodes.PageOutOfRange ("PDF_RENDER_PAGE_OUT_OF_RANGE") when pageNumber1Based > pageCount.
• PdfRenderErrorCodes.RenderFailed ("PDF_RENDER_FAILED") for invalid PDFs, missing/incorrect passwords, or any PDFium error.

Usage

Pass the document password argument when the PDF is protected. Pages are 1-based. Prefer Lyo.Pdf.Ocr when you need to combine rasterization with IOcrEngine and project bounding boxes back into PDF coordinates.

Dependencies

Generated from ProjectReference / PackageReference (same model as docs/Lyo.ProjectGraph.html).

• Lyo.Common — (direct, lyo)
• Lyo.Exceptions — (direct, lyo)
• Lyo.Result — (direct, lyo)
• Microsoft.Extensions.DependencyInjection.Abstractions 10.0.5 — (direct, microsoft)
• Microsoft.Extensions.Logging.Abstractions 10.0.5 — (direct, microsoft)
• PDFtoImage 5.2.1 — (direct, third-party)
• SixLabors.ImageSharp 3.1.12 — (direct, third-party)
• System.Memory 4.6.3 — (transitive, microsoft, netstandard2.0)
• System.Text.Json 10.0.5 — (transitive, microsoft, netstandard2.0)