This article demonstrates how to set the transparency of image on a PDF file using Spire.PDF for Java.
import com.spire.pdf.*; import com.spire.pdf.graphics.*; import java.awt.geom.*; import java.awt.*; public class ImageTransparency { public static void main(String[] args) { //Create a PDFDocument PdfDocument doc = new PdfDocument(); //Add a section PdfSection section = doc.getSections().add(); // Load image and set its width and height PdfImage image = PdfImage.fromFile("logo.png"); double imageWidth = image.getPhysicalDimension().getWidth() / 3; double imageHeight = image.getPhysicalDimension().getHeight() / 3; //Add a page PdfPageBase page = section.getPages().add(); float pageWidth = (float) page.getCanvas().getClientSize().getWidth(); float y = 10; //Draw Title and set the font and format y = y + 5; PdfBrush brush = new PdfSolidBrush(new PdfRGBColor(new Color(255,69,0))); PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Arial", Font.BOLD,12)); PdfStringFormat format = new PdfStringFormat(PdfTextAlignment.Center); String text = String.format(" Set image Transparency "); page.getCanvas().drawString(text, font, brush, pageWidth / 2, y, format); Dimension2D size = font.measureString(text, format); y = y + (float) size.getHeight() + 6; //Set image transparency page.getCanvas().setTransparency(0.2f, 0.2f, PdfBlendMode.Normal); //Add image to the page page.getCanvas().drawImage(image, 0, y, imageWidth, imageHeight); page.getCanvas().save(); // Save pdf file. doc.saveToFile("output/Transparency.pdf"); // Close pdf file doc.close(); } }
Effective screenshot after adding the image to PDF and set the image transparency: