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generating design with java

i am trying to generate following given sateen design with help of my java code but this code is not creating png file named sateen
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
public class Sateen {
BufferedImage image;
int width;
int height;
int red,green,blue;
public Sateen() {
try {
File input = new File("n.png");
image = ImageIO.read(input);
width = image.getWidth();
height = image.getHeight();
//n is png file with only white pixels
for(int i=0; i<height; i++){
for(int j=0; j<width; j++){
Color p = new Color(image.getRGB(j, i));
Color g = new Color(image.getRGB(j+5, i));
//getting (j,i) coordinate pixel value and then comparing it to next 5th pixel
if(p.getRed()==255&&p.getBlue()==255&&p.getGreen()==255&&g.getRed()==255&&
g.getBlue()==255&&g.getGreen()==255)
{ red=0;
blue=0;
green=0; }
//if both pixel value is white then setting 5th pixel value to black
Color newColor = new Color(red,green,blue);
image.setRGB(j+5,i,newColor.getRGB());
j=j+5;
}
}
File ouptut = new File("Sateen.png");
ImageIO.write(image, "png", ouptut);
//creating sateen png file
} catch (Exception e) {}
}
static public void main(String args[]) throws Exception
{
Sateen obj = new Sateen();
}
}

Seems to actually create a .png file (make sure the filepath is correct?). However this code will not generate a sateen pattern, rather draws black pixels at column 6, 12, 18 etc.

The following code fixes some issues in your code. Although it produces an output file but the output file does not look like what you are trying to produce. Perhaps you need to tweak your algorithm?
Anyway the main thing to learn here is that if you are looping over arrays and incrementing the index within the loop then you need to take care of the situation where your index might go out of bounds of the array i.e. your j+5 can be anything outside the image.
Also, make sure that your input file is in the correct location which will depend on where you run the program from. If you run it from the debugger/IDE then it should be inside the project folder next to the src folder. It would be better if you specify full path to your file i.e. C:\SomeFolder\n.png to avoid input file missing error.
Finally, use something like e.printStackTrace(); in your catch block to find out where and why your code is failing.
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
public class Sateen {
BufferedImage image;
int width;
int height;
int red, green, blue;
public Sateen() {
try {
File input = new File("n.png");
image = ImageIO.read(input);
width = image.getWidth();
height = image.getHeight();
// n is png file with only white pixels
for (int i = 0; i < height; i++) {
for (int j = 0; j < width; j++) { // may not need j++ as you are doing j+5?
Color p = new Color(image.getRGB(j, i));
int jPlus5 = j + 5;
if (jPlus5 < width) {
Color g = new Color(image.getRGB(jPlus5, i));
// getting (j,i) coordinate pixel value and then
// comparing
// it to next 5th pixel
if (p.getRed() == 255 && p.getBlue() == 255 && p.getGreen() == 255 && g.getRed() == 255 &&
g.getBlue() == 255 && g.getGreen() == 255)
{
red = 0;
blue = 0;
green = 0;
}
// if both pixel value is white then setting 5th pixel
// value
// to black
Color newColor = new Color(red, green, blue);
image.setRGB(jPlus5, i, newColor.getRGB());
}
j = jPlus5;
}
}
File ouptut = new File("Sateen.png");
ImageIO.write(image, "png", ouptut);
// creating sateen png file
} catch (Exception e) {
e.printStackTrace();
}
}
static public void main(String args[]) throws Exception
{
Sateen obj = new Sateen();
}
}

change color of bitmap

I'm trying to create a function that gets a bitmap and destiny color and returns the colored bitmap (without using paint). I found few ways of doing it but nothing works like I want it to.
The closest solution I was able to find is:
public static Bitmap changeImageColor(Bitmap srcBmp, int dstColor) {
int width = srcBmp.getWidth();
int height = srcBmp.getHeight();
float srcHSV[] = new float[3];
float dstHSV[] = new float[3];
Bitmap dstBitmap = Bitmap.createBitmap(width, height, Config.RGB_565);
for (int row = 0; row < height; row++) {
for (int col = 0; col < width; col++) {
Color.colorToHSV(srcBmp.getPixel(col, row), srcHSV);
Color.colorToHSV(dstColor, dstHSV);
// If it area to be painted set only value of original image
dstHSV[2] = srcHSV[2]; // value
int color2=Color.HSVToColor(dstHSV);;
dstBitmap.setPixel(col, row, Color.HSVToColor(dstHSV));
}
}
return dstBitmap;
}
but It doesn't work very well on transparent images as can be seen here (before and after):
Anyone has any other solutions (again without using paint at all)?

You just need to extract alpha and re-apply it after transformation. And use ARGB_8888;
Edited your code to include alpha:
public Bitmap colorize(Bitmap srcBmp, int dstColor) {
int width = srcBmp.getWidth();
int height = srcBmp.getHeight();
float srcHSV[] = new float[3];
float dstHSV[] = new float[3];
Bitmap dstBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
for (int row = 0; row < height; row++) {
for (int col = 0; col < width; col++) {
int pixel = srcBmp.getPixel(col, row);
int alpha = Color.alpha(pixel);
Color.colorToHSV(pixel, srcHSV);
Color.colorToHSV(dstColor, dstHSV);
// If it area to be painted set only value of original image
dstHSV[2] = srcHSV[2]; // value
dstBitmap.setPixel(col, row, Color.HSVToColor(alpha, dstHSV));
}
}
return dstBitmap;
}

here is a sample code for change the color for a bitmap:
private BitmapDrawable getColoredBitmap(int color, Context context,
int drawableId) {
Bitmap source = BitmapFactory.decodeResource(context.getResources(),
drawableId);
final Bitmap bitmap = Bitmap.createBitmap(source.getWidth(),
source.getHeight(), Bitmap.Config.ARGB_8888);
for (int i = 0; i < source.getWidth(); i++) {
for (int j = 0; j < source.getHeight(); j++) {
int pixel = source.getPixel(i, j);
// if (pixel == Color.TRANSPARENT) {
//
// } else
if (pixel == Color.WHITE) {
pixel = Color.argb(Color.alpha(pixel),
Color.red(Color.WHITE), Color.green(Color.WHITE),
Color.blue(Color.WHITE));
} else {
pixel = Color.argb(Color.alpha(pixel), Color.red(color),
Color.green(color), Color.blue(color));
}
bitmap.setPixel(i, j, pixel);
}
}
return new BitmapDrawable(context.getResources(), bitmap);
}

You do this:
int alpha=srcBmp.getPixel(col, row);
dstBitmap.setPixel(col, row, Color.HSVToColor(dstHSV));
in which you calculate an alpha (probably incorrectly from the looks of that code) and then don't use it. You are probably going to have to create a Color with HSVToColor, then set the alpha of that color, then use it in setPixel. And you are probably going to have to get the alpha in a similar way because I find it hard to believe a getPixel function only returns the alpha :p

Slow map in java

I'm making a game in java, is a rpg, however, only with the map the game is slow.
The map is made ​​in TiledMap Editor, therefore, an XML that is read and loaded into an ArrayList. My PC is a dual-core 3.0, 4GB RAM, 1GB Video.
The do the rendering is done as follows:
//method of tileset class
public void loadTileset(){
positions = new int[1 + tilesX * tilesY][2];
int yy = 0;
int xx = 0;
int index = 0;
// save the initial x and y point of each tile in an array named positions
// positions[tileNumber] [0] - X position
// positions[tileNumber] [1] - Y position
for(int i = 1 ; i < positions.length; i++){
if(index == tilesX ){
yy += tileHeight;
xx = 0;
index = 0;
}
positions[i][0] = xx;
positions[i][1] = yy;
xx += tileWidth;
index++;
}
}
//method of map class
public void draw(Graphics2D screen){
//x and y position of each tile on the screen
int x = 0; int y = 0;
for(int j = 0; j < 20 ; j++){
for(int i = initialTile ; i < initialTile + quantTiles ; i++){
int tile = map[j][i];
if(tile != 0){
screen.drawImage(tileSet.getTileImage().getSubimage(tileSet.getTileX(tile), tileSet.getTileY(tile),tileSet.getTileWidth(), tileSet.getTileHeight()),x,y,null);
}
x += tileSet.getTileWidth();
}
x = 0;
y += tileSet.getTileHeight();
}
}
Am I doing something wrong?
Note: I'm new to the forum and to make matters worse I do not understand very much English, so excuse any mistake.

First of all, you should not create the subimages for the tiles during each call. Strictly speaking, you should not call getSubimage at all for images that you want to paint: It will make the image "unmanaged", and this can degrade rendering performance by an order of magnitude. You should only call getSubimage for images that you do not want to render - for example, when you are initially creating individual images for the tiles.
You obviously already have a TileSet class. You could add a bit of functionality to this class so that you can directly access images for the tiles.
Your current code looks like this:
screen.drawImage(
tileSet.getTileImage().getSubimage(
tileSet.getTileX(tile),
tileSet.getTileY(tile),
tileSet.getTileWidth(),
tileSet.getTileHeight()),
x,y,null);
You could change it to look like this:
screen.drawImage(tileSet.getTileImage(tile), x,y,null);
The getTileImage(int tile) method suggested here could then obtain tiles that have been stored internally.
I'll sketch a few lines of code from the tip of my head, you'll probably be able to transfer this into your TileSet class:
class TileSet
{
private Map<Integer, BufferedImage> tileImages;
TileSet()
{
....
prepareTileImages();
}
private void prepareTileImages()
{
tileImages = new HashMap<Integer, BufferedImage>();
for (int tile : allPossibleTileValuesThatMayBeInTheMap)
{
// These are the tiles that you originally rendered
// in your "draw"-Method
BufferedImage image =
getTileImage().getSubimage(
getTileX(tile),
getTileY(tile),
getTileWidth(),
getTileHeight());
// Create a new, managed copy of the image,
// and store it in the map
BufferedImage managedImage = convertToARGB(image);
tileImages.put(tile, managedImage);
}
}
private static BufferedImage convertToARGB(BufferedImage image)
{
BufferedImage newImage = new BufferedImage(
image.getWidth(), image.getHeight(),
BufferedImage.TYPE_INT_ARGB);
Graphics2D g = newImage.createGraphics();
g.drawImage(image, 0, 0, null);
g.dispose();
return newImage;
}
// This is the new method: For a given "tile" value
// that you found at map[x][y], this returns the
// appropriate tile:
public BufferedImage getTileImage(int tile)
{
return tileImages.get(tile);
}
}

OpenCV-Android: Import .png preserving transparency of empty areas

I am currently trying to transform an input .png file to a OpenCV:Mat, preserving its transparency on empty areas. Working on eclipse, using openCV4Android.
I've tried this (using a Drawable):
Inputs:
icon.png is a resource file that is correctly loaded as RGBA (4 channels).
Mat mcSprite (global field).
onCameraFrame method{
try {
mcSprite = Utils.loadResource(this, R.drawable.icon);
System.out.println(mcSprite.empty());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Imgproc.resize(mcSprite, mZoomWindow, mZoomWindow.size());
}
The resulting image:
PS: If i import using:
mcSprite = Utils.loadResource(this, R.drawable.icon , -1);
>0 Return a 3-channel color image.
=0 Return a grayscale image.
<0 Return the loaded image as is (with alpha channel).
no image is displayed.

A lot faster solution, using masks:
public Mat overlayImage(Mat background, Mat foreground)//, Point location)
{
Mat mask = new Mat();
Imgproc.resize(mCurrentMask, mask, background.size());
Mat source = new Mat();
Imgproc.resize(foreground, source, background.size());
source.copyTo(background,mask);
source.release();
mask.release();
return background;
}
public void createMask (Mat sprite){
mCurrentMask = new Mat(sprite.height(),sprite.width(),24);
double f[] = {1,1,1,0};
double e[] = {0,0,0,0};
for(int y = 0; y < (int)(sprite.rows()) ; ++y)
{
for(int x = 0; x < (int)(sprite.cols()) ; ++x)
{
double info[] = sprite.get(y, x);
if(info[3]>0) //rude but this is what I need
{
mCurrentMask.put(y, x, f);
}
else mCurrentMask.put(y, x, e);
}
}
}

Solved:
public void overlayImage(Mat background, Mat foreground,Mat output)//, Point location)
{
background.copyTo(output);
Mat dst = new Mat();
Imgproc.resize(foreground, dst, background.size());
double alpha;
// start at row 0/col 0
for(int y = 0; y < background.rows() ; ++y)
{
for(int x = 0; x < background.cols() ; ++x)
{
double info[] = dst.get(y, x);
alpha = info[3];
// and now combine the background and foreground pixel, using the opacity,but only if opacity > 0.
if(alpha>0) //rude but this is what I need
{
double infof[] = dst.get(y, x);
output.put(y, x, infof);
}
}
}
Final Result:

Making a Certain Color on a BufferedImage Become Transparent

A very similar question that has been answered: How to make a color transparent in a BufferedImage and save as PNG
Unfortunately I couldn't formulate an answer for myself out of that source.
Q: I draw a BufferedImage to my Canvas and would simply like to create a method that turns every pixel with the a certain color (in this case: [214, 127, 255] / 0xD67FFF) into a transparent one. The BufferedImage is of type ARGB.
I do not want to save the BufferedImage as a file, simply display it on my canvas.
Thanks in advance.

Iterate over all the pixels and perform the check and make transparent.
for (int y = 0; y < image.getHeight(); ++y) {
for (int x = 0; x < image.getWidth(); ++x) {
int argb = image.getRGB(x, y);
if ((argb & 0x00FFFFFF) == 0x00D67FFF)
{
image.setRGB(x, y, 0);
}
}
}
Make sure the BufferedImage uses an alpha channel, otherwise it will become black.
Note that this will affect your original image.
Edit: Note that I changed the check. Therefor it wouldn't have worked because of I assume your pixels were solid (alpha = 255).
(0xFFD67FFF & 0x00FFFFFF) will result in 0x00D67FFF
And, (0x00D67FFF == 0x00D67FFF)

For a complete solution, like loading, processing and writing, you can use this code:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class TransparentConverter {
private static final Color backColor = Color.GREEN;
private static final int THRESHOLD = 70;
private static final int TRANSPARENT = 0; // 0x00000000;
static File base = new File("C:\\images");
static File base2 = new File("C:\\images2");
public static void main(String[] args) throws IOException {
System.out.println("TransparentConverter.main()");
for (File file : base.listFiles()) {
System.out.println(file);
BufferedImage initImage = ImageIO.read(file);
int width = initImage.getWidth(null),
height = initImage.getHeight(null);
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics g = image.getGraphics();
g.drawImage(initImage, 0, 0, null);
//System.out.println("before: " + image.getRGB(0, 0));
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++) {
int pixel = image.getRGB(x, y);
Color color = new Color(pixel);
int dr = Math.abs(color.getRed() - backColor.getRed()),
dg = Math.abs(color.getGreen() - backColor.getGreen()),
db = Math.abs(color.getBlue() - backColor.getBlue());
if (dr < THRESHOLD && dg < THRESHOLD && db < THRESHOLD) {
image.setRGB(x, y, TRANSPARENT);
}
}
}
//System.out.println(" after: " + image.getRGB(0, 0));
file = new File(base2, file.getName());
//System.out.println(" " + file);
ImageIO.write(image, "png", file);
}
}
}