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How can I get white colored pixel value from gray scale image and replace it with another color?

I am trying to get the value of the White Colored pixel from a GrayScale image and replace it with another Color but when I run my code, the whole GrayScale image is transfered to another Color. Can anyone please tell me where is fault in the code or how can I get my desired results??
This is the code...
public class gray {
public static void main (String args[])throws IOException{
int width;
int height;
BufferedImage myImage = null;
File f = new File("E:\\eclipse\\workspace\\Graphs\\src\\ColorToGray\\1.png");
myImage = ImageIO.read(f);
width = myImage.getWidth();
height = myImage.getHeight();
BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_ARGB);
int pixels[];
pixels = new int[width * height];
myImage.getRGB(0, 0, width, height, pixels, 0, width);
for (int i = 0; i < pixels.length; i++) {
if (pixels[i] == 0xFFFFFF) {
pixels[i] = 0x000000FF;
}
}
File f2 = new File("E:\\eclipse\\workspace\\Graphs\\src\\ColorToGray\\out 1.png");
image.setRGB(0, 0, width, height, pixels, 0, width);
ImageIO.write( image, "jpg", f2);
}
}
Image Before:
Image Before Output
Image After:
Image After Output

I looked into it, and found a bunch of problems.
First of all, when specifying the filename to save, you supply a ".png" extension, but when you call the ImageIO.write() function, you specify file type "jpg". That tends not to work very well. If you try to open up the resulting file, most programs will give you a "this is not a valid .PNG file" error. Windows explorer tries to be smart, and re-interprets the .PNG as a .JPG, but this spared you from the chance of discovering your mistake.
This takes care of the strange redness problem.
However, if you specify "png" in ImageIO.write(), you still don't get the right image. One would expect an image that looks mostly like the original, with just a few patches of blue there where bright white used to be, but instead what we get is an overall brighter version of the original image.
I do not have enough time to look into your original image to find out what is really wrong with it, but I suspect that it is actually a bright image with an alpha mask that makes it look less bright, AND there is something wrong with the way the image gets saved that strips away alpha information, thus the apparent added brightness.
So, I tried your code with another image that I know has no tricks in it, and still your code did not appear to do anything. It turns out that the ARGB format of the int values you get from myImage.getRGB(); returns 255 for "A", which means that you need to be checking for 0xFFFFFFFF, not 0x00FFFFFF.
And of course when you replace a value, you must replace it with 0xFF0000FF, specifying a full alpha value. Replacing a pixel with 0x000000FF has no visible effect, because regardless of the high blue value, alpha is zero, so the pixel would be rendered transparent.

Fit setIcon to JButton Array

I know this has been asked a ton of times, but I've searched everywhere and still haven't found an answer. I'm relatively new to Java. I have
JButton b[][];
Later, I assign b[3][3].setIcon(path). However, the image at path is always a small section of the actual image the size of the JButton. What I want is to re-size the image to fit the size of the JButton. Is there any way to do this? By the way, here's some code that's (I think) is important:
int n = 8;
int m = 8;
...
b = new JButton[n][m];
setLayout(new GridLayout(n,m));
for (int y = 0;y<m;y++){
for (int x = 0;x<n;x++){
b[x][y] = new JButton(" ");
b[x][y].addActionListener(this);
add(b[x][y]);
b[x][y].setEnabled(true);
}
}

What I want is to re-size the image to fit the size of the JButton.
You can use the Stretch Icon class.
It will allow you to automatically resize the Icon:
to fill the space of the button, or
keep the Icon proportion and fill the space of the button
The resizing is done dynamically so you don't need scaled images.

What you obviously need is a Icon Resizer method, something in the way of what I have provided below:
public static Icon resizeIcon(ImageIcon icon, int resizedWidth, int resizedHeight) {
Image img = icon.getImage();
Image img = img.getScaledInstance(resizedWidth, resizedHeight, java.awt.Image.SCALE_SMOOTH);
return new ImageIcon(img);
}
You can call this method after the image has already been applied to the JButton and after it has been added to whatever panel:
b[3][3].setIcon(path)
b[3][3].setIcon(resizeIcon((ImageIcon) b[3][3].getIcon(),
b[3][3].getWidth() - 15, b[3][3].getHeight() - 15));
or you could do it this way:
ImageIcon img = new ImageIcon("MyImage.png");
Icon icn = resizeIcon(img, b[3][3].getWidth() - 15, b[3][3].getHeight() - 15);
b[3][3].setIcon(icn);

Upscale 2D low-res images

I am using the program ImageResizer with the XBR4x algorithm to upscale .gif images from an old 2D game from 32x32 to 48x48.
The exact procedure:
Manually rename all images to .jpeg because the program wont open .gif
Resize the images, they are saved by the program as .bmp
Manually rename the images to .gif again.
The problem:
When looking at the images in Paint they look very good, when drawn in my RGB BufferedImage they suddenly all have a white/grey ~1px border which is not the Background Color, the images are placed directly next to each other. As I have a whole mosaic of those images the white borders are a no go.
Image 32x32:
Image 48x48 after upscaling:
Ingame screenshot of 4 of those earth images with white borders:
The question:
How do those borders originate? And if not possible to answer this, are there more reliable methods of upscaling low resolution game images making them look less pixelated?

I think that is an artifact of the image resizing algorithm, the borders are actually visible one the upscaled image before it is combined, if you look at them in XnView, for example.
The best way to fix that would be to use another tool to resize the image, one which allows the user to control such borderline effects, but if you have to use this one you could still work around the problem by constructing a 3x3 grid of the original image (which would be 96x96), scaling it up to 144x144 and then cutting out the central 48x48 piece. This would eliminate the borderline effects.

The border is a result of a scaling procedure performed by the mentioned tool. Consider this demo that shows tiles based on scaled image from the question and scaled image created using Image.getScaledInstance().
Note that if you choose to stay with your own scaling method check out The Perils of Image.getScaledInstance() for more optimized solutions.
import java.awt.Graphics;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class TestImageScale {
public static void main(String[] args) {
try {
BufferedImage original = ImageIO.read(new URL(
"http://i.stack.imgur.com/rY2i8.gif"));
Image scaled = original.getScaledInstance(48, 48,
Image.SCALE_AREA_AVERAGING);
BufferedImage scaledOP = ImageIO.read(new URL(
"http://i.stack.imgur.com/Argxi.png"));
BufferedImage tilesOP = buildTiles(scaledOP, 3, 3);
BufferedImage tiles = buildTiles(scaled, 3, 3);
JPanel panel = new JPanel();
panel.add(new JLabel(new ImageIcon(tilesOP)));
panel.add(new JLabel(new ImageIcon(tiles)));
JOptionPane.showMessageDialog(null, panel,
"Tiles: OP vs getScaledInstance",
JOptionPane.INFORMATION_MESSAGE);
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e.getMessage(), "Failure",
JOptionPane.ERROR_MESSAGE);
e.printStackTrace();
}
}
static BufferedImage buildTiles(Image tile, int rows, int columns) {
int width = tile.getWidth(null);
int height = tile.getHeight(null);
BufferedImage dest = GraphicsEnvironment
.getLocalGraphicsEnvironment()
.getDefaultScreenDevice()
.getDefaultConfiguration()
.createCompatibleImage(width * rows, height * columns,
Transparency.TRANSLUCENT);
Graphics g = dest.getGraphics();
for (int row = 0; row < rows; row++) {
for (int col = 0; col < columns; col++) {
g.drawImage(tile, row * width, col * width, null);
}
}
g.dispose();
return dest;
}
}

Just a wild guess: Do the original images have an Alpha channel (or do you implicitly create one when resizing)? When resizing an image with alpha, the scaling process may assume the area outside the image to be transparent and the border pixels may become partially transparent, too.

I emailed Hawkynt, the developer of the tool and it seems the error is not in the tool but in Microsofts implementation and he fixed it (actually even bigger tools like Multiple Image Resizer .NET have the problem). This is what he said about his program:
"When you entered width and/or height manually, the image got resized by the chosen algorithm where everything went fine.
Afterwards I used the resample command from GDI+ which implements a Microsoft version of the bicubic resize algorithm.
This implementation is flawed, so it produces one pixel on the left and upper side for images under 300px.
I fixed it by simply making the resized image one pixel larger than wanted and shifting it to the left and up one pixel, so the white border is no longer visible and the target image hast he expected dimensions."

java image crop

I am aware of BufferedImage.getSubimage However, it cant deal with cropping images that are smaller than the cropping size throwing the exception:
java.awt.image.RasterFormatException: (y + height) is outside raster
I want to be able to crop either a PNG/JPG/GIF to a certain size however if the image is smaller than the cropping area centre itself on a white background. Is there a call to do this? Or do I need to create an image manually to centre the image on if so, how would I go about this?
Thanks

You cannot crop an image larger, only smaller. So, you start with the goal dimension,let's say 100x100. And your BufferedImage (bi), let's say 150x50.
Create a rectangle of your goal:
Rectangle goal = new Rectangle(100, 100);
Then intersect it with the dimensions of your image:
Rectangle clip = goal.intersection(new Rectangle(bi.getWidth(), bi.getHeight());
Now, clip corresponds to the portion of bi that will fit within your goal. In this case 100 x50.
Now get the subImage using the value of clip.
BufferedImage clippedImg = bi.subImage(clip,1, clip.y, clip.width, clip.height);
Create a new BufferedImage (bi2), the size of goal:
BufferedImage bi2 = new BufferedImage(goal.width, goal.height);
Fill it with white (or whatever bg color you choose):
Graphics2D big2 = bi2.getGraphics();
big2.setColor(Color.white);
big2.fillRect(0, 0, goal.width, goal.height);
and draw the clipped image onto it.
int x = goal.width - (clip.width / 2);
int y = goal.height - (clip.height / 2);
big2.drawImage(x, y, clippedImg, null);

How to get the coordinate of Gridlayout

I set my JPanel to GridLayout (6,6), with dimension (600,600)
Each cell of the grid will display one pictures with different widths and heights.
The picture first add to a JLabel, and the JLabel then added to the cells.
How can retrieved the coordinate of the pictures in the cells and not the coordinate of cells? So far the out give these coordinate which equal height and width even on screen the pictures showed in different sizes.
e.g.
java.awt.Rectangle[x=100,y=100,width=100,height=100]
java.awt.Rectangle[x=200,y=100,width=100,height=100]
java.awt.Rectangle[x=300,y=100,width=100,height=100]
The reason why I used GridLayout instead of gridBagLayout is that, I want each pictures to have boundary. If I use GridBagLayout, the grid will expand according to the picture size.
I want grid size to be in fix size.
JPanel pDraw = new JPanel(new GridLayout(6,6));
pDraw.setPreferredSize(new Dimension(600,600));
for (int i =0; i<(6*6); i++)
{
//get random number for height and width of the image
int x = rand.nextInt(40)+(50);
int y = rand.nextInt(40)+(50);
ImageIcon icon = createImageIcon("bird.jpg");
//rescale the image according to the size selected
Image img = icon.getImage().getScaledInstance(x,y,img.SCALE_SMOOTH);
icon.setImage(img );
JLabel label = new JLabel(icon);
pDraw.add(label);
}
for(Component component:components)
{
//retrieve the coordinate
System.out.println(component.getBounds());
}
EDITED: I have tried this but not working :-(
for(Component component: pDraw.getComponents()){
System.out.println(((JLabel)component).getIcon());
}
How can I get output like these?
java.awt.Rectangle[x=300,y=100,width=50,height=40]
java.awt.Rectangle[x=400,y=400,width=60,height=50]

Do your images appear at the desired size ?
i think so.
Anyway, from what your code seems to do, I guess it gets the labels size, and not the icons size. JLabel, like any JComponent, are in fact Container instance. As such, their size depends upon constraints. As a consequence, in a GridLayout, a JLabel will have the size of a cell, whereas the contained Icon will have the size of the image.
As a consquence, to get image size, you have to call ((JLabel) component).getIcon() to be able to retrieve effective image dimension.