Java PDF to Image Conversion using PDFBox

Here are few snippets of code that you can use to convert a PDF file to images eg: tiff, png, multi-page tiff. It uses a open source library PDFBox version 3

The Apache PDFBox^® library is an open source Java tool for working with PDF documents. This project allows creation of new PDF documents, manipulation of existing documents and the ability to extract content from documents.

PDFBox comes with following features:

• Extract Unicode text from PDF files.
• Split a single PDF into many files or merge multiple PDF files.
• Extract data from PDF forms or fill a PDF form.
• Validate PDF files against the PDF/A-1b standard.
• Print a PDF file using the standard Java printing API.
• Save PDFs as image files, such as PNG or JPEG.
• Create a PDF from scratch, with embedded fonts and images.

Convert PDF to PNG/JPG/BMP etc:

colored object tracking in java- javacv code

Code for this demo video - Color Based Image Segmentation to Track Path of Moving Object


Working Source Code :

import static com.googlecode.javacv.cpp.opencv_core.IPL_DEPTH_8U;
import static com.googlecode.javacv.cpp.opencv_core.cvCreateImage;
import static com.googlecode.javacv.cpp.opencv_core.cvFlip;
import static com.googlecode.javacv.cpp.opencv_core.cvGetSize;
import static com.googlecode.javacv.cpp.opencv_core.cvInRangeS;
import static com.googlecode.javacv.cpp.opencv_core.cvScalar;
import static com.googlecode.javacv.cpp.opencv_imgproc.CV_BGR2GRAY;
import static com.googlecode.javacv.cpp.opencv_imgproc.CV_MEDIAN;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvCvtColor;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvEqualizeHist;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvGetCentralMoment;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvGetSpatialMoment;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvMoments;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvSmooth;
import static com.googlecode.javacv.cpp.opencv_highgui.*;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;

import javax.swing.JPanel;

import com.googlecode.javacv.CanvasFrame;
import com.googlecode.javacv.FrameGrabber;
import com.googlecode.javacv.VideoInputFrameGrabber;
import com.googlecode.javacv.cpp.opencv_core.CvScalar;
import com.googlecode.javacv.cpp.opencv_core.IplImage;
import com.googlecode.javacv.cpp.opencv_imgproc.CvMoments;

public class ColoredObjectTrack implements Runnable {
    final int INTERVAL = 1000;// 1sec
    final int CAMERA_NUM = 0; // Default camera for this time

Java grey image from RGB image convert full source code

The java code below is for making grey image from a image

public static void main(String[] args) {
        BufferedImage org = getImage("test.jpg");
        BufferedImage greyImage = getGrayScaleAvg(org);
        new ImageFrame(org, "Original");
        new ImageFrame(greyImage, "After GrayScale");
    }

Full working source code : averages the pixels to obtain grey image

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;

public class tempgrey {
    public static void main(String[] args) {
        BufferedImage org = getImage("test.jpg");//valid input image
        BufferedImage greyImage = getGrayScaleAvg(org);
        new ImageFrame(org, "Original");
        new ImageFrame(greyImage, "After GrayScale");
    }

    public static BufferedImage getImage(String imageName) {
        try {
            File input = new File(imageName);
            BufferedImage image = ImageIO.read(input);
            return image;

simple ball game by colored object motion tracking - image processing opencv javacv

DEMO VIDEO:  simple ball game by colored object motion tracking - using javacv opencv to detect the path of moving object. This is earliest version of the game.


Full Code :
Java Collision Detection and bounce

Colored object tracking in java- javacv code

You need to integrate the ideas from above links.
The full (integrated code will be uploaded shortly)

Object tracking in Java - detect position of colored spot in image

Red spot in image - position to be detected later

Object Tracking plays important role in Image Processing research projects. In this example, I am showing how we can detect the position [(x, y) coordinates ] of a colored spot in given image using JavaCV (Java wrapper for OpenCV ).



Input image :
This image has a red colored spot. And our objective is to track the position coordinate of the spot in image.The example below uses thresholding in HSV space and simple moment calculations given in OpenCV library.





You can use this code to track an object in a video sequence - say live web-cam capture video.

• The code for capturing webcam using JavaCV is here.
• Help on Configuring a JavaCV project in Eclipse+windows is here.

Detecting Position of a spot in Threshold image:

    static Dimension getCoordinates(IplImage thresholdImage) {
        int posX = 0;
        int posY = 0;

JavaCV: Image Thresholding HSV color space

JavaCV (OpenCv) example of image thresholding based on color in HSV-A Space - to detect red color spot on given image. Useful in object tracking.

Java Source Code:

//imports
import static com.googlecode.javacv.cpp.opencv_core.*;
import static com.googlecode.javacv.cpp.opencv_highgui.*;
import static com.googlecode.javacv.cpp.opencv_imgproc.*;
import com.googlecode.javacv.cpp.opencv_core.CvScalar;
import com.googlecode.javacv.cpp.opencv_core.IplImage;

public class ColorDetect {

Tracking Path of Moving Object by Color Based Image Segmentation

Codes(using JavaCV) available here (two parts):
Thresholding operation and position detection in an image
Capturing the video frames from webcam

Demo Video 42 Secs.

JavaCV - Color based thresholding in image using OpenCV

JavaCV - Red color based thresholding (RGB-A space) in image using OpenCV : Full working java source code 


Note that the order of colors is BGR-A not RGB-A. 
Read it more from http://stackoverflow.com/questions/367449/bgr-color-space

#Similar example but on HSV-A space is given here :

//static imports
import static com.googlecode.javacv.cpp.opencv_core.*;
import static com.googlecode.javacv.cpp.opencv_highgui.*;
import static com.googlecode.javacv.cpp.opencv_imgproc.*;
//non-static imports
import com.googlecode.javacv.cpp.opencv_core.CvScalar;
import com.googlecode.javacv.cpp.opencv_core.IplImage;

JavaCV- Image load, smooth and save

Static Imports:
import static com.googlecode.javacv.cpp.opencv_core.*;
import static com.googlecode.javacv.cpp.opencv_imgproc.*;
import static com.googlecode.javacv.cpp.opencv_highgui.*;

Image Smoothing:
public static void smoothSave(String filename) throws Exception {
IplImage image = cvLoadImage(filename);
System.out.println(image.nSize());
if (image != null) {
cvSmooth(image, image, CV_BLUR, 3);
cvSaveImage("smoothed_" + filename, image);
cvReleaseImage(image);
}
}

OpenCV-JavaCV : eclipse project configuration windows 7

NOTE: A Easier and Simpler version of the installation step is available !!  Check the latest ( Jan , 2017) article.

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Eclipse (windows 7) project setup for JNA wrapper of OpenCV : JavaCV - getting started.

OpenCV (Open Source Computer Vision Library) is library of programming functions for real time computer vision.  JavaCV provides wrappers to commonly used libraries for OpenCV and few others.

Download the Essentials :

Java Image Processing : Negative of Input Image - source code

The code below is for getting negative of an input image in JAVA:

public class TestImagesss {
    public static void main(String[] args) {
        BufferedImage org = getImage("test.jpg");
        BufferedImage negative = getNegativeImage(org);
        new ImageFrame(org, "Original");
        new ImageFrame(negative, "After Negative");

Java: Loading images in JFrame - Reusable ImageFrame

Sometimes we need to show multiple images in separate window by using single line statement :

new ImageFrame(inImg, "Input Image ");// inImg is reference to Image object

The code below can be used to load images in JFrame as a separate window.

Java Image - read image and separate RGB array values

Reading image and getting values of Red Green Blue and Alpha values in separate 2d arrays :

public class TestImagesss {
    public static void main(String[] args) {
        int value[][]=getRGB(getImage("test.jpg"));
        int valueR[][]=getR(getImage("test.jpg"));
    }
    //.... code below :