org.jpedal.images.SamplingFactory Maven / Gradle / Ivy

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/*
 * ===========================================
 * Java Pdf Extraction Decoding Access Library
 * ===========================================
 *
 * Project Info:  http://www.idrsolutions.com
 * Help section for developers at http://www.idrsolutions.com/support/
 *
 * (C) Copyright 1997-2017 IDRsolutions and Contributors.
 *
 * This file is part of JPedal/JPDF2HTML5
 *
 @LICENSE@
 *
 * ---------------
 * SamplingFactory.java
 * ---------------
 */
package org.jpedal.images;

public class SamplingFactory {

    /**
     * do nothing
     */
    public static int none;

    /**
     * medium will make sure images larger than page are reduced in size (often large scanned tiffs)
     */
    public static final int medium = 1;

    /**
     * (default setting) high will agressively reduce images bigger than twice their drawn size at 100% so a image
     * which appears as 100x100 on the PDF but whose raw images is 250x250 will be stored as 125x125 image
     * and not a 250x250 image
     */
    public static final int high = 2;

    /**
     * use down-sampling on printing (which is default)
     */
    public static final int print_enable = 3;

    /**
     * do not use down-sampling on printing
     */
    public static final int print_disable = 4;

    /**
     * medium will make sure images larger than page are reduced in size (often large scanned tiffs)
     */
    public static final int mediumAndSharpen = 5;

    /**
     * (default setting) high will agressively reduce images bigger than twice their drawn size at 100% so a image
     * which appears as 100x100 on the PDF but whose raw images is 250x250 will be stored as 125x125 image
     * and not a 250x250 image
     */
    public static final int highAndSharpen = 6;


    /**
     * current setting - do not set directly
     */
    public static int downsampleLevel = high;

    /**
     * current setting - do not set directly
     */
    public static boolean isPrintDownsampleEnabled = true;

    public static boolean kernelSharpen;

    //sharpening kernel
    private static double[][] sharpenKernel = {{0, -1, 0}, {-1, 5, -1}, {0, -1, 0}};

    /* 5x5 version
    private static double[][] sharpenKernel = {{0,0, 0, 0,0},{0,0, -1, 0,0},{0,-1, 5, -1,0},{0,0, -1, 0,0},{0,0, 0, 0,0}};
    /**/

    /**
     * PDFs contain images which may often be much larger than the actual space they occupy and they are reduced to fit the space

     * alters image sampling to speed up program and reduce memory in with the strategies "high","medium", "none", "enable_printing", "disable_printing"
     *
     * @param newLevel A String value of image sampling strategies
     */
    public static void setDownsampleMode(String newLevel) {

        if (newLevel == null) {
            newLevel = System.getProperty("org.jpedal.downsample");
        }

        if (newLevel != null) {
            if (newLevel.equals("high") || newLevel.equals("\"high\"")) {
                downsampleLevel = high;
            } else if (newLevel.equals("medium") || newLevel.equals("\"medium\"")) {
                downsampleLevel = medium;
            } else if (newLevel.equals("none") || newLevel.equals("\"none\"")) {
                downsampleLevel = none;
            } else if (newLevel.equals("print_disable") || newLevel.equals("\"print_disable\"")) {
                isPrintDownsampleEnabled = false;
            } else if (newLevel.equals("print_enable") || newLevel.equals("\"print_enable\"")) {
                isPrintDownsampleEnabled = true;
            }
        }

    }

    /**
     * PDFs contain images which may often be much larger than the actual space they occupy and they are reduced to fit the space

     * alters image sampling to speed up program and reduce memory with the strategies high, medium, none, enable_printing, disable_printing
     *
     * @param newLevel A String value of image sampling strategies
     */
    @SuppressWarnings("UnusedDeclaration")
    public static void setDownsampleMode(final int newLevel) {

        if (newLevel == high || newLevel == highAndSharpen || newLevel == medium || newLevel == mediumAndSharpen || newLevel == none) {
            downsampleLevel = newLevel;
        } else if (newLevel == print_disable) {
            isPrintDownsampleEnabled = false;
        } else if (newLevel == print_enable) {
            isPrintDownsampleEnabled = true;
        }

    }

    /**
     * allow user to over-ride default setting and set their own
     * 3x3 kernel to sharpen down-sampled images
     *
     * @param userKernel Kernel used to sharpen image
     */
    public static void setSharpenKernel(final double[][] userKernel) {
        sharpenKernel = userKernel;
    }

    public static double[][] getSharpenKernel() {
        return sharpenKernel;
    }
}