Develop Reference

Gradient color issue when converting from pptx to images. Apache POI

I have created pptx and ppt converter to images using apache poi but while converting some file i have an exception after two or three converts.
Exception in thread "main" java.lang.IllegalArgumentException: Color parameter outside of expected range: Red
Main converter from both pptx and ppt
import org.apache.poi.hslf.model.Slide;
import org.apache.poi.hslf.usermodel.SlideShow;
import org.apache.poi.xslf.usermodel.XMLSlideShow;
import org.apache.poi.xslf.usermodel.XSLFSlide;
import java.awt.*;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
public class Application {
public static void main(String[] args) throws Exception {
System.out.println("working");
String directory = System.getProperty("user.home") + "/Desktop/";
//creating an empty presentation
File file=new File(directory + "test6.pptx");
String fileName = file.getName();
// Identify the file whether it is ppt or pptx
String extension = fileName.substring(fileName.lastIndexOf(".") + 1);
FileInputStream inputStream = new FileInputStream(directory + fileName);
if (extension.equals("pptx")) {
XMLSlideShow pptx = new XMLSlideShow(inputStream);
//getting the dimensions and size of the slide
Dimension pgsize = pptx.getPageSize();
java.util.List<XSLFSlide> pptxSlide = Arrays.asList(pptx.getSlides());
for (int i = 0; i < pptxSlide.size(); i++) {
BufferedImage img = new BufferedImage(pgsize.width, pgsize.height,BufferedImage.TYPE_INT_RGB);
Graphics2D graphics = createImage(img, pgsize);
//render
pptxSlide.get(i).draw(graphics);
graphics.setComposite(AlphaComposite.DstOver);
graphics.setPaint(Color.WHITE);
//creating an image file as output
imageFile(i, img);
graphics.dispose();
}
}else if(extension.equals("ppt")){
SlideShow ppt = new SlideShow(inputStream);
//getting the dimensions and size of the slide
Dimension pgsize = ppt.getPageSize();
List<Slide> slide = Arrays.asList(ppt.getSlides());
for (int i = 0; i < slide.size(); i++) {
BufferedImage img = new BufferedImage(pgsize.width, pgsize.height,BufferedImage.TYPE_INT_RGB);
//render
slide.get(i).draw(createImage(img, pgsize));
//creating an image file as output
imageFile(i, img);
}
}else {
throw new Exception("Not compatible type ");
}
}
private static void imageFile(int i, BufferedImage img) throws IOException {
FileOutputStream out = new FileOutputStream("ppt_image_" + i + ".png");
javax.imageio.ImageIO.write(img, "png", out);
System.out.println("Image successfully created");
out.close();
}
private static Graphics2D createImage(BufferedImage img, Dimension pgsize){
Graphics2D graphics = img.createGraphics();
//clear the drawing area
graphics.setPaint(Color.white);
graphics.fill(new Rectangle2D.Float(0, 0, pgsize.width, pgsize.height));
// default rendering options
graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
graphics.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
graphics.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
graphics.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
graphics.setComposite(AlphaComposite.DstOver);
return graphics;
}
}
The main problem is that I want to convert any pptx file any kind of with gradient or simple colors to images.
Converted gradient slide [greyed]

Use java to render a jpg file

I am trying to write a simple code to write a red 100x100 jpg
For some reason the colors are not right,
I am only setting the color RED :
renderdImg.setRGB(x, y, Color.RED.getRGB());
but the fnal image comes out purplish, what am I doing wrong?
import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class ImageWriter {
public static void main(String[] args) throws IOException {
String fileName = "red_100.jpg";
String filePath = "c:\\temp\\";
int width = 100;
int height = 100;
BufferedImage renderdImg = new BufferedImage(width,height, BufferedImage.TYPE_INT_ARGB);
for(int x=0;x< width; x++) {
for(int y=0;y<height; y++) {
renderdImg.setRGB(x, y, Color.RED.getRGB());
}}
File fileToWrite = new File(filePath + fileName);
ImageIO.write(renderdImg, "jpg", fileToWrite);
}
}

Set the image type to BufferedImage.TYPE_INT_RGB and it should become reddish:
BufferedImage renderdImg = new BufferedImage(width,height, BufferedImage.TYPE_INT_RGB);

How To Convert Image .dcm to Graycale in Java

please i need help
I am trying to convert image .dcm to grayscale in java but i couldn't.
i wan't to know how to read image.dcm in java and convert it to grayscale.
note :: this code is already run for image .jpg,.png
package otsuthresholding;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;
public class OtsuThresholding {
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
try {
System.loadLibrary(Core.NATIVE_LIBRARY_NAME );
File input = new File("p.dcm");
BufferedImage image = ImageIO.read(input);
byte[] data = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
Mat mat = new Mat(image.getHeight(), image.getWidth(), CvType.CV_8UC3);
mat.put(0, 0, data);
Mat mat1 = new Mat(image.getHeight(),image.getWidth(),CvType.CV_8UC1);
Imgproc.cvtColor(mat, mat1, Imgproc.COLOR_RGB2GRAY);
byte[] data1 = new byte[mat1.rows() * mat1.cols() * (int)(mat1.elemSize())];
mat1.get(0, 0, data1);
BufferedImage image1 = new BufferedImage(mat1.cols(),mat1.rows(), BufferedImage.TYPE_BYTE_GRAY);
image1.getRaster().setDataElements(0, 0, mat1.cols(), mat1.rows(), data1);
File ouptut = new File("grayscale.dcm");
ImageIO.write(image1, "dcm", ouptut);
} catch (IOException e) {
System.out.println("Error: " + e.getMessage());
}
}
}

Java - Motion / Object detection (Human detection) using OpenCV

I got the video stream from cctv camera using opencv. Now I want to detect a simple motion / object from this video stream. For example, if any person come in any selected zone then rectangular border should be generated around him. I search some opencv tutorial, but I didn't got any proper solution or idea.I used the following code to display video stream.
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.highgui.Highgui;
import org.opencv.highgui.VideoCapture;
import org.opencv.imgproc.Imgproc;
import org.opencv.objdetect.CascadeClassifier;
public class VideoStream
{
static BufferedImage tmpImg=null;
public static void main(String args[]) throws InterruptedException
{
System.out.println("opencv start..");
// Load native library
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
VideoCapture camView=new VideoCapture();
camView.open("http://192.168.1.7:80/cgi-bin/view.cgi?chn=6&u=admin&p=");
if(!camView.isOpened())
{
System.out.println("Camera Error..");
}
else
{
System.out.println("Camera successfully opened");
}
videoCamera cam=new videoCamera(camView);
//Initialize swing components
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(cam);
frame.setSize(1024,768);
frame.setVisible(true);
while(camView.isOpened())
{
cam.repaint();
}
}
}
#SuppressWarnings("serial")
class videoCamera extends JPanel
{
VideoCapture camera;
Mat mat=new Mat();
public videoCamera(VideoCapture cam)
{
camera = cam;
}
public BufferedImage Mat2BufferedImage(Mat m)
{
int type = BufferedImage.TYPE_BYTE_GRAY;
if (m.channels() > 1)
{
type = BufferedImage.TYPE_3BYTE_BGR;
}
int bufferSize = m.channels() * m.cols() * m.rows();
byte[] b = new byte[bufferSize];
m.get(0, 0, b); // get all the pixels
BufferedImage img = new BufferedImage(m.cols(), m.rows(), type);
final byte[] targetPixels = ((DataBufferByte) img.getRaster().getDataBuffer()).getData();
System.arraycopy(b, 0, targetPixels, 0, b.length);
return img;
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Mat mat = new Mat();
camera.read(mat);
BufferedImage image = Mat2BufferedImage(mat);
g.drawImage(image,0,0,image.getWidth(),image.getHeight(), null);
}
}
Can any one knows how could we do that.

please check this code, but i implement it by python
import cv2, time, pandas
from datetime import datetime
first_frame = None
status_list = [None,None]
times = []
df=pandas.DataFrame(columns=["Start","End"])
video = cv2.VideoCapture('rtsp://admin:Paxton10#10.199.27.128:554')
while True:
check, frame = video.read()
status = 0
gray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)
gray = cv2.GaussianBlur(gray,(21,21),0)
if first_frame is None:
first_frame=gray
continue
delta_frame=cv2.absdiff(first_frame,gray)
thresh_frame=cv2.threshold(delta_frame, 30, 255, cv2.THRESH_BINARY)[1]
thresh_frame=cv2.dilate(thresh_frame, None, iterations=2)
(cnts,_)=cv2.findContours(thresh_frame.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
for contour in cnts:
if cv2.contourArea(contour) < 200000:
continue
status=1
(x, y, w, h)=cv2.boundingRect(contour)
cv2.rectangle(frame, (x, y), (x+w, y+h), (0,255,0), 3)
status_list.append(status)
status_list=status_list[-2:]
if status_list[-1]==1 and status_list[-2]==0:
times.append(datetime.now())
if status_list[-1]==0 and status_list[-2]==1:
times.append(datetime.now())
#cv2.imshow("Gray Frame",gray)
#cv2.imshow("Delta Frame",delta_frame)
imS = cv2.resize(thresh_frame, (640, 480))
cv2.imshow("Threshold Frame",imS)
imS = cv2.resize(frame, (640, 480))
cv2.imshow("Color Frame",imS)
#cv2.imshow("Color Frame",frame)
key=cv2.waitKey(1)
if key == ord('q'):
if status == 1:
times.append(datetime.now())
break
print(status_list)
print(times)
for i in range(0, len(times), 2):
df = df.append({"Start": times[i],"End": times[i+1]}, ignore_index=True)
df.to_csv("Times.csv")
video.release()
cv2.destroyAllWindows

How to change JPEG image DPI using java [duplicate]

This question already has answers here:
decrease image resolution in java
(4 answers)
Closed 8 years ago.
can any one help me..?
I have some .jpg's created from JPanel. Unfortunately its DPI is 72. Is there a programmatic way to change the DPI of these .jpg's ?
Now i use following code for change DPI. But it have some issues when i try to build project.
`JPEGImageEncoder jpegEncoder = JPEGCodec.createJPEGEncoder(new FileOutputStream(outfile));
JPEGEncodeParam jpegEncodeParam = jpegEncoder.getDefaultJPEGEncodeParam(image);
jpegEncodeParam.setDensityUnit(JPEGEncodeParam.DENSITY_UNIT_DOTS_INCH);
jpegEncodeParam.setXDensity(300);
jpegEncodeParam.setYDensity(300);
jpegEncoder.encode(image, jpegEncodeParam);`
Thanks in advance :)

You can scale an image using Graphics2D methods (from java.awt). This tutorial at http://www.mkyong.com/java/how-to-resize-an-image-in-java explains it in depth.
here is an example
import java.awt.*;
import java.awt.image.*;
import java.io.*;
import java.net.*;
import javax.imageio.*;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.awt.Image;
import java.io.File;
import java.io.FileOutputStream;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.stream.FileImageInputStream;
import javax.swing.ImageIcon;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
public class ImageManipulation {
public static void main(String[] args) throws Exception {
File infile = new File("/your image.jpg");
File outfile = new File("/your image.jpg");
ImageReader reader = ImageIO.getImageReadersByFormatName("jpeg").next();
reader.setInput(new FileImageInputStream(infile), true, false);
IIOMetadata data = reader.getImageMetadata(0);
BufferedImage image = reader.read(0);
int w = 600, h = -1;
Image rescaled = image.getScaledInstance(w, h, Image.SCALE_AREA_AVERAGING);
BufferedImage output = toBufferedImage(rescaled, BufferedImage.TYPE_INT_RGB);
Element tree = (Element) data.getAsTree("javax_imageio_jpeg_image_1.0");
Element jfif = (Element) tree.getElementsByTagName("app0JFIF").item(0);
for (int i = 0; i < jfif.getAttributes().getLength(); i++) {
Node attribute = jfif.getAttributes().item(i);
System.out.println(attribute.getNodeName() + "="
+ attribute.getNodeValue());
}
FileOutputStream fos = new FileOutputStream(outfile);
JPEGImageEncoder jpegEncoder = JPEGCodec.createJPEGEncoder(fos);
JPEGEncodeParam jpegEncodeParam = jpegEncoder.getDefaultJPEGEncodeParam(output);
jpegEncodeParam.setDensityUnit(JPEGEncodeParam.DENSITY_UNIT_DOTS_INCH);
jpegEncodeParam.setXDensity(300);
jpegEncodeParam.setYDensity(300);
jpegEncoder.encode(output, jpegEncodeParam);
fos.close();
}
public static BufferedImage toBufferedImage(Image image, int type) {
int w = image.getWidth(null);
int h = image.getHeight(null);
BufferedImage result = new BufferedImage(w, h, type);
Graphics2D g = result.createGraphics();
g.drawImage(image, 0, 0, null);
g.dispose();
return result;
}
}

There is a similar question about resolution, answered in the following SO question here.
In general, you may be interested in learning image processing algorithms, which are described here:
The basic concept in decreasing resolution is that you are selectively
deleting data from the image.