This is a sample Java program showing how to crop a page in Java using Qoppa’s PDF library jPDFProcess.

This small snippet shows how to open a PDF, get the first page, set a new crop box and save the cropped PDF to a new file name.

// Open PDF file
PDFDocument pdfDoc = new PDFDocument("C:\\test\\mydocument.pdf", null);
// Get first page
PDFPage page = pdfDoc.getPage(0);
// Define the new crop box, which is a rectangle that is used to crop content
// before displaying or printing the page. This rectangle is in PDF native
// coordinates starting at the bottom left and increasing up to the right.
// The dimensions are given in PostScript points.
// 1 inch = 72 points, 1cm = 28.3465 points, 1mm = 2.8346 points
// width in points
double crop_width = 200;
// height in points
double crop_height = 300;
// bottom left corner coordinates in points
double x_1 = 20;
double y_1 = 20;
Rectangle2D.Double area = new Rectangle2D.Double(x_1, y_1, crop_width, crop_height);
// set the new crop box
// save the cropped document

When cropping a PDF, the actual content is still present but hidden. Only the display or print area is changed.