images/image_mask

 * Image mask:

 * Place an image with a mask applied to it

 *

 * Place an image and apply a Grayscale mask on it. Depending on the values

 * contained in the mask, the image pixels will be displayed more or less

 * transparent. Smaller (darker) mask values result in more transparent image

 * pixels and larger (lighter) values in less transparency.

 *

 * Required software: PDFlib Lite/PDFlib/PDFlib+PDI/PPS 7

 * Required data: image file

 */

package com.pdflib.cookbook.pdflib.images;

import com.pdflib.pdflib;

import com.pdflib.PDFlibException;

public class image_mask

{

    public static void main (String argv[])

    {

    /* This is where the data files are. Adjust as necessary. */

    String searchpath = "../input";

    String outfile = "image_mask.pdf";

    String title = "Image Mask";

    pdflib p = null;

    String imagefile = "sky.jpg";

    String maskfile = "image_mask.jpg";

    int font, image, mask, masked_image;

    try {

        p = new pdflib();

        p.set_parameter("SearchPath", searchpath);

        /* This means we must check return values of load_font() etc. */

        p.set_parameter("errorpolicy", "return");

        if (p.begin_document(outfile, "") == -1)

            throw new Exception("Error: " + p.get_errmsg());

        p.set_info("Creator", "PDFlib Cookbook");

        p.set_info("Title", title + " $Revision: 1.6 $");

        /* Load the original image */

        image = p.load_image("auto", imagefile, "");

        if (image == -1)

            throw new Exception("Error: " + p.get_errmsg());

        /* Load the Grayscale image to be used as the transparency mask */

        mask = p.load_image("auto", maskfile, "mask");

        if (mask == -1)

            throw new Exception("Error: " + p.get_errmsg());

        /* Load the image with the transparency mask being assigned to it */

        masked_image = p.load_image("auto", imagefile, "masked " + mask);

        if (masked_image == -1)

            throw new Exception("Error: " + p.get_errmsg());

        /* Load font */

        font = p.load_font("Helvetica", "unicode", "");

        if (font == -1)

            throw new Exception("Error: " + p.get_errmsg());

        /* Start a page with a size similar to the image dimensions.

         * The "transparencygroup" option improves output quality when placing

         * the image on a page which contains transparent objects (image or

         * other).

         * PDFlib 7.0.3 will automatically create the "transparencygroup"

         * option, so it is only required in earlier versions.

         */

        p.begin_page_ext(0, 0, "width=a4.height height=a4.width " +

            "transparencygroup={CS=DeviceRGB}");

        /* Place the original image */

        p.fit_image(image, 50, 150, "boxsize {200 500} fitmethod=meet");

        p.fit_textline("Original image", 50, 130, "font=" + font +

            " fontsize=14");

        /* Place the image without the clipping path being applied to it */

        p.fit_image(mask, 300, 150, "boxsize {200 500} fitmethod=meet");

        p.fit_textline("Transparency mask", 300, 130, "font=" + font +

            " fontsize=14");

        /* Place the image with the clipping path being applied to it */

        p.fit_image(masked_image, 550, 150, "boxsize {200 500} fitmethod=meet");

        p.fit_textline("Image with the transparency mask applied.", 550, 130,

            "font=" + font + " fontsize=10");

        p.fit_textline("Darker mask values result in more transparent image " +

            "values.", 550, 110, "font=" + font + " fontsize=10");

        /* Close the images */

        p.close_image(image);

        p.close_image(mask);

        p.close_image(masked_image);

        p.end_page_ext("");

        p.end_document("");

        } catch (PDFlibException e) {

            System.err.print("PDFlib exception occurred:\n");

            System.err.print("[" + e.get_errnum() + "] " + e.get_apiname() +

                ": " + e.get_errmsg() + "\n");

        } catch (Exception e) {

            System.err.println(e.getMessage());

        } finally {

            if (p != null) {

                p.delete();

            }

        }

    }

}