Can I change the contrast of an image from the byte stream of the Image? I have done necessary to do copying the image and I need to add the change contrast part to the code.
Any idea how to do this? Or is it even possible?
package make.image.bw;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
public class MakeImageBWActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main); // set screen view
String imageInSD = Environment.getExternalStorageDirectory().getAbsolutePath() +"/earthglobe.jpg";
RandomAccessFile file = null;
try {
file = new RandomAccessFile(imageInSD, "r");
} catch (FileNotFoundException e1) {
e1.printStackTrace();
}
File myFile = new File(Environment.getExternalStorageDirectory(), "latestearth.jpg");
byte[] buffer = new byte[1024];
try {
FileOutputStream out = new FileOutputStream(myFile);
while(file.read(buffer)!=-1){
out.write(buffer,0,1024);
}
out.close();
} catch (IOException e) {
e.printStackTrace();
}
Log.d("tag", "finished");
finish();
}
}
Thanking You in advance for your valuable suggestions.
You should try to look at that Google IO 2012 session : Doing More With Less: Being a Good Android Citizen
There is a good demo of image manipulation with RenderScript at 22min30.
The code of the presentation can be found here
Related
How to transfer a file(unknown extension ie maybe a pdf/word/jpeg) from PC to Android Phone using Socket Programming. The Android Phone should be able to detect the type of file transfer and should be able to open it thereafter. Also the file should go into a specific folder named after app name in External storage.
I have tried following solution. However in this case, when I select the file to be transferred, the file transferred at Android side is of arbitrary size and not of the same size as of file selected, it is of some random size. Also the file transferred cannot be opened as it does not have a fixed extension.
Any help would be appreciated.
Android code(To receive file)
package minor.subham.com.pccontrol;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Environment;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;
import java.net.*;
import java.io.*;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
public class getFile extends ActionBarActivity {
ImageView getFile;
public final static int SOCKET_PORT = Constants.SERVER_PORT; // you may change this
public final static String SERVER = Constants.SERVER_IP; // localhost
public final static int FILE_SIZE = 6022386; // file size temporary hard coded
// should bigger than the file to be downloaded
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_get_file);
getFile = (ImageView) findViewById(R.id.getFile);
getFile.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Thread thread = new Thread() {
#Override
public void run() {
while(true) {
int bytesRead;
int current = 0;
FileOutputStream fos = null;
BufferedOutputStream bos = null;
Socket sock = null;
final File file;
file = new File(Environment.getExternalStorageDirectory(), "PcControl");
try {
sock = new Socket(SERVER, SOCKET_PORT);
System.out.println("Connecting...");
// receive file
byte [] mybytearray = new byte [FILE_SIZE];
InputStream is = sock.getInputStream();
// fos = new FileOutputStream(FILE_TO_RECEIVED);
try {
fos = new FileOutputStream(file);
} catch (IOException e) {
e.printStackTrace();
}
bos = new BufferedOutputStream(fos);
bytesRead = is.read(mybytearray,0,mybytearray.length);
current = bytesRead;
do {
bytesRead =
is.read(mybytearray, current, (mybytearray.length-current));
if(bytesRead >= 0) current += bytesRead;
} while(bytesRead > -1);
bos.write(mybytearray, 0 , current);
bos.flush();
fos.write(mybytearray);
fos.close();
System.out.println("File "
+ " downloaded (" + current + " bytes read)");
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (fos != null) try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
if (bos != null) try {
bos.close();
} catch (IOException e) {
e.printStackTrace();
}
if (sock != null) try {
sock.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
};
thread.start();
}
});
}
}
And Her is the Java Code to send file. Suppose I want to send file temp.jpg
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class send {
public final static int SOCKET_PORT = 8991; // you may change this
public final static String FILE_TO_SEND = "temp.jpg"; // you may change this
public static void main (String [] args ) throws IOException {
FileInputStream fis = null;
BufferedInputStream bis = null;
OutputStream os = null;
ServerSocket servsock = null;
Socket sock = null;
try {
servsock = new ServerSocket(SOCKET_PORT);
// while (true) {
System.out.println("Waiting...");
try {
sock = servsock.accept();
System.out.println("Accepted connection : " + sock);
// send file
File myFile = new File (FILE_TO_SEND);
byte [] mybytearray = new byte [(int)myFile.length()];
fis = new FileInputStream(myFile);
bis = new BufferedInputStream(fis);
bis.read(mybytearray,0,mybytearray.length);
os = sock.getOutputStream();
System.out.println("Sending " + FILE_TO_SEND + "(" + mybytearray.length + " bytes)");
os.write(mybytearray,0,mybytearray.length);
os.flush();
System.out.println("Done.");
}
finally {
if (bis != null) bis.close();
if (os != null) os.close();
if (sock!=null) sock.close();
}
// }
}
finally {
if (servsock != null) servsock.close();
}
}
}
I Downloaded both jars from http://www.siegmann.nl/epublib/android
but the sample code does not create a file
in my sdcard or internal storage
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import nl.siegmann.epublib.domain.Author;
import nl.siegmann.epublib.domain.Book;
import nl.siegmann.epublib.epub.EpubWriter;
import android.app.Activity;
import android.os.Bundle;
public class EpubAppActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Book b = new Book();
b.getMetadata().addTitle("test epub book");
b.getMetadata().addAuthor(new Author("author name"));
EpubWriter w = new EpubWriter();
FileOutputStream fos;
try {
File file = new File(getApplicationContext().getExternalFilesDir(null), "test.epub");
if(!file.exists()){
file.createNewFile();
}
fos = new FileOutputStream(file);
w.write(b, fos);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
not get error however I can not find the file (it is not created)
I forgot to add
<uses-permission android: name = "android.permission.WRITE_EXTERNAL_STORAGE" />
in Android Manifest
I have written simple code to save data into text files internally. But, after running the code, I don't know where I can find the required file. Additionally, I find an error message in the log cast as
"SPAN_EXCLUSIVE_EXCLUSIVE"
package com.example.saving_files;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
public class MainActivity extends Activity {
File file;
FileOutputStream fos;
String FlieName = "output.text";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
file = new File(FlieName);
try {
fos = openFileOutput(FlieName, MODE_PRIVATE);
fos.write(122);
} catch (FileNotFoundException e) {
Log.d("output", file.getAbsolutePath());
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
file = getFilesDir();
Log.d("output_path", file.getAbsolutePath());
}
}
File sdCard = Environment.getExternalStorageDirectory();
File file = new File(sdCard, "filename");
FileOutputStream f = new FileOutputStream(file);
This code will create new file in the root directory of your SD. Dont forget to add
<uses-permission> to write to SD in your manifest
Check this code and comments;
File sdcard = Environment.getExternalStorageDirectory();
File f = new File(sdcard, "/yourfile");
if (!f.exsist()) {
f.createNewFile();
// Use outwriter here, (outputstream) search how to write into a text file in java code
}
here is my entire code (ps Im a noobie);
package xom.aaa.aaa;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class FilewritertestActivity extends Activity {
TextView textout1, textout2, textout3;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button b1 = (Button) findViewById(R.id.button1);
textout1 = (TextView) findViewById(R.id.textView1);
textout2 = (TextView) findViewById(R.id.textView2);
textout3 = (TextView) findViewById(R.id.textView3);
b1.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
//--------- OutputStreamWriter ------------
try {
FileOutputStreamfOut=openFileOutput("settings1.dat", MODE_WORLD_READABLE);
OutputStreamWriter osw = new OutputStreamWriter(fOut);
osw.write( "using fileoutput stream to write this to a file");
osw.flush();
osw.close();
}catch(Exception e){
e.printStackTrace(System.err);
}
String datax = "";
StringBuffer buffer = new StringBuffer();
//--------- InputStreamReader -------------------
try {
FileInputStream fIn = openFileInput("settings1.dat");
Reader reader = new InputStreamReader(fIn);
int data = reader.read(); // reads the next char
while(data != -1){
buffer.append((char)data);
data = reader.read();
}
reader.close();
} catch ( Exception e) {
e.printStackTrace();
}
textout1.setText( buffer.toString());
//--------------- FileWriter ---------------
try {
FileWriter fw = new FileWriter("settings1.dat");
BufferedWriter out = new BufferedWriter(fw);
//BufferedWriter out = new BufferedWriter(new FileWriter("settings1.dat"));
out.write("a String");
out.close();
} catch (Exception e){
e.printStackTrace();
textout2.setText(e.toString());
}
}
});
}
}
Problem is FileWriter Not working ( for file "settings1.dat")
but OutputStreamWriter and InputStreamReader does work ( for file "settings1.dat")
the code shows writing then reading to file "settings1.dat" Is ok with Stream Witer/Reader...
But FileWriter code get error message Filenotfoundexception "read-only file system"
So why does one technique work on the same File and the other doesn´t
Can you please tell what Iam missing -- thanks Trevor
I'm guessing your problem is you just aren't getting an IOException. You could try changing
catch(IOException e)
to
catch(Exception e)
This will then catch all exceptions which extend the Exception object (it will not catch Errors though). However, I don't have the tools to test out your code so you will have to try it out yourself and post the results.
Best of luck.
I am using the code below to download and show image from server to my ImageView
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
public class HTTPTest extends Activity {
ImageView imView;
String imageUrl="http://11.0.6.23/";
Random r= new Random();
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
Button bt3= (Button)findViewById(R.id.get_imagebt);
bt3.setOnClickListener(getImgListener);
imView = (ImageView)findViewById(R.id.imview);
}
View.OnClickListener getImgListener = new View.OnClickListener()
{
#Override
public void onClick(View view) {
// TODO Auto-generated method stub
//i tried to randomize the file download, in my server i put 4 files with name like
//png0.png, png1.png, png2.png so different file is downloaded in button press
int i =r.nextInt(4);
downloadFile(imageUrl+"png"+i+".png");
Log.i("im url",imageUrl+"png"+i+".png");
}
};
Bitmap bmImg;
void downloadFile(String fileUrl){
URL myFileUrl =null;
try {
myFileUrl= new URL(fileUrl);
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
HttpURLConnection conn= (HttpURLConnection)myFileUrl.openConnection();
conn.setDoInput(true);
conn.connect();
int length = conn.getContentLength();
InputStream is = conn.getInputStream();
bmImg = BitmapFactory.decodeStream(is);
imView.setImageBitmap(bmImg);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
This code works file for all format of images but when it comes to PNG it wont let the image transparent after download and displaying on ImageView.
Any idea?
I dont know it will be a solution for you or not
But you can use a Drawable instead of Bitmap
Here is the code
void downloadFile(String fileUrl) {
try{
InputStream is = (InputStream) new URL(fileUrl).getContent();
Drawable d = Drawable.createFromStream(is, "src name");
imgView.setImageDrawable(d);
} catch (IOException e) {
e.printStackTrace();
}
}
This will show a png correctly