Apache PDFBox - Image to PDF

🔧 Operation Name

Apache PDFBox – Image to PDF imageToPdf

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🧾 Description

Converts a single image (e.g., JPG, PNG, GIF, BMP) into a one-page PDF document. The resulting PDF has a single page sized to match the dimensions of the source image.

Perfect for embedding scanned receipts, screenshots, or images into a PDF workflow.

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✅ Inputs

• Image File [Binary] (InputStream) Binary content of the image (JPEG, PNG, etc.).

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📤 Output

• Payload: InputStream (binary stream) A one-page PDF containing the provided image.

• Attributes: PdfBoxFileAttributes Metadata of the generated PDF: number of pages (always 1), file size, creation date, etc.

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🔍 Notes

• The generated page is automatically sized to the image’s pixel dimensions (no scaling).

• You can adjust scaling or margins later by combining this with other operations (e.g., rotatePages, filterPages).

• Currently supports formats loadable by PDImageXObject (PNG, JPEG, BMP, GIF).

• Always outputs a single-page PDF regardless of the image dimensions.

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Underlying Application Interface:

pdfbox 3.0.6 javadoc (org.apache.pdfbox)javadoc.io

Pseudo Code

Operation: imageToPdf

Input:

imageStream: Binary content of the image (InputStream)

streamingHelper: MuleSoft StreamingHelper (for context/utilities)

Output:
Result containing:

A single InputStream representing the new one-page PDF document.

PdfBoxFileAttributes containing metadata of the generated PDF (page count, size, etc.).

Errors:

PDF_PROCESSING_ERROR: If the input is not a valid image or embedding fails.

PDF_METADATA_EXTRACTION_FAILED: If metadata cannot be retrieved from the generated PDF.

Steps:

Convert the imageStream to a byte array.

Create a new empty PDDocument.

Try to create a PDImageXObject from the byte array inside the document.

If this fails, throw a ModuleException with PDF_PROCESSING_ERROR.

Get the width and height of the image from the PDImageXObject.

Create a new PDRectangle using the image’s width and height.

Create a new PDPage with this rectangle and add it to the document.

Create a PDPageContentStream bound to the new page.

Draw the image on the page at coordinates (0,0) with full width and height.

Close the content stream.

Create a ByteArrayOutputStream.

Save the PDF document to the ByteArrayOutputStream.

Try to extract metadata from the PDF (using extractPdfMetadata).

If extraction fails, throw a ModuleException with PDF_METADATA_EXTRACTION_FAILED.

Convert the ByteArrayOutputStream to a ByteArrayInputStream.

Create a new Result object containing:

The ByteArrayInputStream as output.

The PdfBoxFileAttributes as attributes.

Return the Result object.

In a finally block, ensure the PDDocument is closed to release resources.

Methods used from the Apache PDFBox library

📂 Classes & Methods from PDFBox

1. PDDocument

   • new PDDocument() → creates a new empty PDF document.

   • addPage(PDPage page) → adds a new page to the document.

   • save(OutputStream) → saves the document to an output stream.

   • close() → releases resources held by the document.

2. PDImageXObject

   • PDImageXObject.createFromByteArray(PDDocument doc, byte[] imageData, String name) → creates a PDF image object from raw image bytes.

3. PDRectangle

   • new PDRectangle(float width, float height) → defines a rectangle (page size) with the same dimensions as the image.

4. PDPage

   • new PDPage(PDRectangle mediaBox) → creates a new page with the given dimensions.

5. PDPageContentStream

   • new PDPageContentStream(PDDocument doc, PDPage page) → creates a content stream to draw onto a page.

   • drawImage(PDImageXObject image, float x, float y, float width, float height) → draws the image onto the page at (x, y) scaled to width/height.

   • close() → finalizes and closes the content stream.