Charts, OCR and Provenance

These optional packages add capabilities that several document formats share. None of them is a dependency of the Word, Excel, PowerPoint, or PDF packages: you install them only in applications that need charts, text recognition, or Content Credentials.

Charts and diagrams with ChartForgeX

OfficeIMO.ChartForgeX places any ChartForgeX VisualArtifact in a Word paragraph, an Excel range, a PowerPoint slide, or PDF content. Each conversion returns an OfficeVisualConversionResult with SVG or PNG placement bytes, an OfficeDrawing scene for PDF, sizes in points, accessible text, and a fidelity report. Topology, flow, and sequence artifacts can also be projected into native, editable Visio diagrams with shapes, connectors, and Shape Data.

dotnet add package OfficeIMO.ChartForgeX

using ChartForgeX.Core;
using ChartForgeX.Primitives;
using ChartForgeX.Rendering;
using ChartForgeX.VisualArtifacts;
using OfficeIMO.ChartForgeX;
using OfficeIMO.Word;

var chart = Chart.Create().AddLine("Revenue", new[] {
    new ChartPoint(1, 42), new ChartPoint(2, 58), new ChartPoint(3, 73)
});
chart.ConfigureAccessibility(value => value.WithTextAlternative("Quarterly sales", "Revenue: 42, 58 and 73.", "en"));

var context = OfficeVisualDocumentStyle.Default.CreateContext(
    frame: new VisualFrame("Quarterly sales", showLegend: false));
VisualArtifact artifact = chart.Prepare(context).ToArtifact("sales-quarter");

using WordDocument document = WordDocument.Create("sales.docx");
document.AddParagraph().AddVisualArtifact(artifact);
document.Save();

The same artifact can be passed to sheet.AddVisualArtifact("B4:I18", artifact) and slide.AddVisualArtifact(...). Word fits an unsized visual to the paragraph's available content width.

Limits: the default RasterizeWhenNeeded policy falls back to PNG when SVG import is incomplete, which is reported as an approximation and loses vector editability; choose PreserveVector or RequireVector to change that. Cropped Cover fitting is not supported. Native Visio output does not draw static watermarks and recomputes the layout of flow and sequence diagrams; both are reported. See the OfficeIMO.ChartForgeX README.

Mermaid diagrams in Markdown

OfficeIMO.ChartForgeX.Markdown replaces Mermaid code fences with rendered images, using ChartForgeX for parsing, layout, and SVG or PNG output. Diagrams are embedded as SVG by default; PDF draws them as vector content, and Word stores the SVG with a PNG fallback picture. The adapter also configures the static HTML renderer and plugs into the OfficeIMO Markup parser for Word and PowerPoint export.

dotnet add package OfficeIMO.ChartForgeX.Markdown
dotnet add package OfficeIMO.Word.Markdown
dotnet add package OfficeIMO.Markdown.Pdf

using OfficeIMO.ChartForgeX.Markdown;
using OfficeIMO.Markdown;
using OfficeIMO.Markdown.Pdf;
using OfficeIMO.Word.Markdown;

MarkdownDocument document = MermaidMarkdownAdapter.Materialize(
    MarkdownDocument.Parse(File.ReadAllText("report.md")),
    diagnostic => Console.WriteLine(diagnostic.Message));

using var word = document.ToWord(new MarkdownWordExportOptions { FitImagesToContextWidth = true });
word.Save("report.docx");
document.SaveAsPdf("report.pdf");

Limits: supported Mermaid grammar and its static approximations are defined by ChartForgeX. Invalid or unsupported diagrams keep their source fence and report a diagnostic. Mermaid's browser runtime is not used. See the OfficeIMO.ChartForgeX.Markdown README.

OCR

OCR in OfficeIMO is built around one engine-neutral contract. OfficeIMO.Ocr defines IOcrEngine, the request and result models, span geometry in pixels, points, or normalized coordinates, and a shared runner that applies timeouts and concurrency rules. It contains no document parser, network client, native runtime, or process runner. AdaptiveOcrEngine can retry weak recognition with up to four engine configurations and reports when a human review is recommended.

The same engine plugs into OfficeIMO.Reader.Ocr for images found in Word, Excel, PowerPoint, OneNote, EPUB, email, and PDF content, into OfficeIMO.Pdf.Ocr for searchable PDFs, and into the DjVu PDF adapter. See the Reader and PDF guides for those integrations.

dotnet add package OfficeIMO.Ocr
dotnet add package OfficeIMO.Ocr.Process
dotnet add package OfficeIMO.Ocr.Tesseract

Tesseract

OfficeIMO.Ocr.Tesseract is an optional IOcrEngine backed by an installed Tesseract command-line executable. It does not bundle native binaries or trained language data; install Tesseract separately for the host operating system. Discovery checks an explicit path, OFFICEIMO_TESSERACT_PATH, TESSERACT_PATH, the process PATH, and common platform locations. The provider returns line and word spans with pixel bounding boxes and normalized confidence, and can detect page orientation.

using OfficeIMO.Ocr;
using OfficeIMO.Ocr.Tesseract;

TesseractOcrSession session = await TesseractOcr.CreateSessionAsync(new TesseractOcrSessionOptions {
    Languages = TesseractOcrLanguage.English | TesseractOcrLanguage.Polish,
    ProvisionMissingLanguageData = false,
    Engine = new TesseractOcrEngineOptions {
        PageSegmentationMode = 3,
        Timeout = TimeSpan.FromMinutes(1)
    }
});

OcrResult result = await session.RecognizeAsync(File.ReadAllBytes("scan.png"), "image/png", "scan.png");
foreach (OcrTextSpan span in result.Spans)
    Console.WriteLine($"{span.Level}: {span.Text} ({span.Confidence:P0})");

TesseractOcr.CreateSessionAsync downloads missing language data by default from one pinned official tessdata_fast commit, checked against package-pinned lengths and SHA-256 digests. Set ProvisionMissingLanguageData = false, as above, to use only the language data already installed. session.Engine is the IOcrEngine to pass to Reader and PDF integrations.

Your own OCR executable

OfficeIMO.Ocr.Process runs an executable you configure, without a command shell, and exchanges a versioned JSON request and response through an isolated per-call directory. Input size, output size, and runtime are bounded, and the process tree is contained so it can be terminated on timeout.

using OfficeIMO.Ocr;
using OfficeIMO.Ocr.Process;

IOcrEngine engine = new ProcessOcrEngine(new ProcessOcrEngineOptions {
    FileName = "/opt/my-ocr/recognize",
    Arguments = new[] { "--request", "{request}" },
    Id = "my-ocr",
    Timeout = TimeSpan.FromMinutes(1)
});

Hosted or in-process recognizers can implement IOcrEngine directly or wrap an existing SDK with DelegateOcrEngine.

Limits: confidence values and review thresholds are starting settings, not calibrated accuracy; high-confidence output can still omit text or misorder columns. Tesseract TSV has no character boxes, so the Tesseract provider returns line and word spans only. Executable paths, arguments, and provider options are trusted host configuration and must not come from document content. See the READMEs for OfficeIMO.Ocr, OfficeIMO.Ocr.Process, and OfficeIMO.Ocr.Tesseract.

C2PA Content Credentials

OfficeIMO.Provenance.C2pa connects OfficeIMO's provider-neutral provenance contracts to the official c2patool command-line application for cryptographic C2PA verification and signing. Structural inspection and provenance policy stay in OfficeIMO.Core and the format packages; ordinary format packages do not depend on this adapter.

dotnet add package OfficeIMO.Provenance.C2pa

OfficeIMO does not download, bundle, or auto-discover c2patool. Install a supported build from the official c2pa-rs releases and pass an absolute path or a command name on your application's controlled PATH. On Unix hosts the adapter also requires setsid; without it, verification and signing fail closed.

using OfficeIMO.Provenance;
using OfficeIMO.Provenance.C2pa;

var verifier = new C2paToolProvenanceVerifier("/opt/c2pa/c2patool");
OfficeProvenanceVerificationResult result = verifier.Verify("image.jpg", new OfficeProvenanceVerificationOptions {
    TrustAnchorsPath = "/etc/my-app/c2pa-trust-anchors.pem",
    IncludeRawReport = false
});

Console.WriteLine(result.Status);
foreach (string finding in result.Findings)
    Console.WriteLine(finding);

Valid means a manifest was found, verified, and produced no findings. Untrusted, Invalid, NotPresent, ProviderUnavailable, Indeterminate, and Error are reported separately. Remote manifest and OCSP fetching are disabled by default. C2paToolProvenanceSigner signs through c2patool 0.27.0 or newer with a signer process backed by your HSM, KMS, or signing service, and installs the signed asset atomically.

Limits: the adapter does not emit watermark actions, because they require soft-binding assertions that OfficeIMO does not create. Built-in test credentials are for development only and are marked as such in results. See the OfficeIMO.Provenance.C2pa README.