.NET에서 PDF 문서 페이지에 워터마크 추가하기
2020/09/11
// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging
// - Vintasoft.Imaging.Pdf
/// <summary>
/// Adds the watermark image to the PDF document.
/// </summary>
/// <param name="inPdfFilename">The filename of input PDF document.</param>
/// <param name="outPdfFilename">The filename of output PDF document.</param>
/// <param name="watermarkImageFilename">The filename of watermark image.</param>
public static void AddWatermarkToPdfDocument(string inPdfFilename, string outPdfFilename, string watermarkImageFilename)
{
AddWatermarkToPdfDocument(inPdfFilename, outPdfFilename, watermarkImageFilename, 0.25f, new Vintasoft.Imaging.PaddingF(0.1f), false);
}
/// <summary>
/// Adds the watermark image to the PDF document.
/// </summary>
/// <param name="inPdfFilename">The filename of input PDF document.</param>
/// <param name="outPdfFilename">The filename of output PDF document.</param>
/// <param name="watermarkImageFilename">The filename of watermark image.</param>
/// <param name="watermarkImageAlpha">The watermark image alpha.</param>
/// <param name="watermarkImagePadding">The watermark image padding.</param>
/// <param name="ignorePageRotation">Indicates that value of Vintasoft.Imaging.Pdf.Tree.PdfPage.Rotate property should be ignored.</param>
public static void AddWatermarkToPdfDocument(
string inPdfFilename,
string outPdfFilename,
string watermarkImageFilename,
float watermarkImageAlpha,
Vintasoft.Imaging.PaddingF watermarkImagePadding,
bool ignorePageRotation)
{
// check watermark padding
if (watermarkImagePadding.Horizontal < 0 || watermarkImagePadding.Vertical < 0)
throw new System.ArgumentOutOfRangeException("watermarkImagePadding");
// open PDF document
using (Vintasoft.Imaging.Pdf.PdfDocument document = new Vintasoft.Imaging.Pdf.PdfDocument(inPdfFilename))
{
// create "watermark" resource
Vintasoft.Imaging.Pdf.Tree.PdfResource watermakResource;
using (Vintasoft.Imaging.VintasoftImage watermarkImage = new Vintasoft.Imaging.VintasoftImage(watermarkImageFilename))
{
// if watermarkImage is PDF page
if (watermarkImage.SourceInfo.DecoderName == "Pdf")
{
// create form resource based on PDF page
Vintasoft.Imaging.Pdf.Tree.PdfPage page = Vintasoft.Imaging.Pdf.PdfDocumentController.GetPageAssociatedWithImage(watermarkImage);
watermakResource = new Vintasoft.Imaging.Pdf.Tree.PdfFormXObjectResource(document, page);
}
else
{
// create watermark image resource with JPEG compression
Vintasoft.Imaging.Pdf.PdfCompression watermarkResourceCompression = Vintasoft.Imaging.Pdf.PdfCompression.Jpeg;
watermakResource = new Vintasoft.Imaging.Pdf.Tree.PdfImageResource(document, watermarkImage, watermarkResourceCompression);
}
}
// for each page in PDF document
foreach (Vintasoft.Imaging.Pdf.Tree.PdfPage page in document.Pages)
{
// add watermark on PDF page
AddWatermarkToPdfPage(page, watermakResource, watermarkImagePadding, watermarkImageAlpha, ignorePageRotation);
}
// pack PDF document to an output file
document.Pack(outPdfFilename);
}
}
/// <summary>
/// Adds the watermark image to the PDF page.
/// </summary>
/// <param name="page">The PDF page.</param>
/// <param name="watermarkResource">The PDF resource that contains watermark.</param>
/// <param name="watermarkImagePadding">The watermark image padding.</param>
/// <param name="watermarkImageAlpha">The watermark image alpha.</param>
/// <param name="ignorePageRotation">Indicates that value of Vintasoft.Imaging.Pdf.Tree.PdfPage.Rotate property should be ignored.</param>
public static void AddWatermarkToPdfPage(
Vintasoft.Imaging.Pdf.Tree.PdfPage page,
Vintasoft.Imaging.Pdf.Tree.PdfResource watermarkResource,
Vintasoft.Imaging.PaddingF watermarkImagePadding,
float watermarkImageAlpha,
bool ignorePageRotation)
{
Vintasoft.Imaging.Pdf.Tree.PdfImageResource watermarkImageResource = watermarkResource as Vintasoft.Imaging.Pdf.Tree.PdfImageResource;
Vintasoft.Imaging.Pdf.Tree.PdfFormXObjectResource watermarkFormResource = watermarkResource as Vintasoft.Imaging.Pdf.Tree.PdfFormXObjectResource;
// gets the size of watermark resource
System.Drawing.SizeF watermarkResourceSize;
if (watermarkImageResource != null)
watermarkResourceSize = new System.Drawing.SizeF(watermarkImageResource.Width, watermarkImageResource.Height);
else
watermarkResourceSize = new System.Drawing.SizeF(watermarkFormResource.BoundingBox.Width, watermarkFormResource.BoundingBox.Height);
// create PDF graphics from PDF page and specify that graphics must clear and add new content
using (Vintasoft.Imaging.Pdf.Drawing.PdfGraphics graphics = Vintasoft.Imaging.Pdf.Drawing.PdfGraphics.FromPage(page))
{
// get mediabox of PDF page
System.Drawing.RectangleF pageMediaBox = page.MediaBox;
// if watermark image must be rotated
if (!ignorePageRotation && page.Rotate != 0)
{
// rotate padding
watermarkImagePadding.Rotate(page.Rotate);
}
// calculate watermark rectangle
System.Drawing.RectangleF watermarkRect = new System.Drawing.RectangleF(
pageMediaBox.X + watermarkImagePadding.Left * pageMediaBox.Width,
pageMediaBox.Y + watermarkImagePadding.Bottom * pageMediaBox.Height,
pageMediaBox.Width - watermarkImagePadding.Horizontal * pageMediaBox.Width,
pageMediaBox.Height - watermarkImagePadding.Vertical * pageMediaBox.Height);
float scale = System.Math.Min(watermarkRect.Width / watermarkResourceSize.Width, watermarkRect.Height / watermarkResourceSize.Height);
System.Drawing.RectangleF watermarkImageRect = new System.Drawing.RectangleF(
watermarkRect.X + (watermarkRect.Width - watermarkResourceSize.Width * scale) / 2,
watermarkRect.Y + (watermarkRect.Height - watermarkResourceSize.Height * scale) / 2,
watermarkResourceSize.Width * scale,
watermarkResourceSize.Height * scale);
// create graphics state parameters
Vintasoft.Imaging.Pdf.Tree.PdfGraphicsStateParameters gsParams = new Vintasoft.Imaging.Pdf.Tree.PdfGraphicsStateParameters(page.Document);
// set blending mode to "Multiply"
gsParams.BlendMode = Vintasoft.Imaging.Pdf.Tree.GraphicsStateBlendMode.Multiply;
// set alpha transparency
gsParams.AlphaForNonStrokingOperations = watermarkImageAlpha;
// save graphics state
graphics.SaveGraphicsState();
// set graphics state parameters
graphics.SetGraphicsStateParameters(gsParams);
// if watermark image must be rotated
if (!ignorePageRotation && page.Rotate != 0)
{
// apply rotation to the PdfGraphics
Vintasoft.Imaging.AffineMatrix matrix = new Vintasoft.Imaging.AffineMatrix();
matrix.RotateAt(
page.Rotate,
watermarkImageRect.X + watermarkImageRect.Width / 2,
watermarkImageRect.Y + watermarkImageRect.Height / 2);
graphics.MultiplyTransform(matrix);
}
// if watermark is an image
if (watermarkImageResource != null)
// draw watermark image
graphics.DrawImage(watermarkImageResource, watermarkImageRect);
else
// draw watermark form
graphics.DrawForm(watermarkFormResource, watermarkImageRect);
// restore graphics state
graphics.RestoreGraphicsState();
}
}