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Cross-stitch image in Java

Let's say I have an image called testimage.jpg, and want to cross-stitch it with a DMC 208 floss (RGB value: 148,91,128)
I got these hints:
Read each pixel's RGB value
Compare it with the floss
Use bilinear interpolation for image scaling
Use Euclidean distance to get the closest color
I think I already figured out how to do step 1. Now I'm wondering how to do step 2, and 4.
BufferedImage img = ImageIO.read(new File("testimage.jpg"));
int imgWidth = img.getWidth();
int imgHeight = img.getHeight();
Color dmc208 = new Color(148,91,128);
Color currentPixel = null;
for (int x = 0; x < imgWidth; x++){
for (int y = 0; y < imgHeight; y++){
currentPixel = new Color(img.getRGB(x, y));
}
}
I know how to calculate the Eulicdean distance, but how to get the"closest" color at that distance?

creating tiles using bufferedImage in java

public static BufferedImage split(BufferedImage img) {
BufferedImage pic = new BufferedImage(img.getWidth(), img.getHeight(), BufferedImage.TYPE_INT_RGB);
Graphics g = pic.getGraphics();
int width = 2000/2;
int height = 2000/2;
int imageW = pic.getWidth();
int imageH = pic.getHeight();
// Tile the image to fill our area.
for (int x = 0; x < width; x += imageW) {
for (int y = 0; y < height; y += imageH) {
g.drawImage(pic, x, y, null);
}
}
return pic ;
}
the point of the code is to create a tile of 2x2 of the image (same image reproduce at a smaller size in a 2x2 grid). i want to updated pic so i can print it onto a jpanel. all i get is black image. can someone tell me whats wrong with the code. or tell me how to create a better piece of code.

I want to make four smaller images of the original and place it in a grid of 2x2 that is the same size as the original image
Something like...
public static BufferedImage split(BufferedImage img) {
BufferedImage pic = new BufferedImage(img.getWidth(), img.getHeight(), BufferedImage.TYPE_INT_RGB);
Graphics g = pic.getGraphics();
int width = pic.getWidth() / 4;
int height = pic.getHeight() / 4;
Image scaled = img.getScaledInstance(width, height, Image.SCALE_SMOOTH);
// Tile the image to fill our area.
for (int x = 0; x < pic.getWidth(); x += width) {
for (int y = 0; y < pic.getHeight(); y += height) {
g.drawImage(scaled, x, y, null);
}
}
g.dispose();
return pic;
}
You may also like to have a look at Java: maintaining aspect ratio of JPanel background image and Quality of Image after resize very low -- Java for more details about how you can improve the scaling algorithm

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

Taking a picture as input, Make grey scale and & then outputting

I'm attempting to take a picture as input, then manipulate said picture (I specifically want to make it greyscale) and then output the new image. This is a snippet of the code that I'm editing in order to do so but I'm getting stuck. Any ideas of what I can change/do next. Greatly appreciated!
public boolean recieveFrame (Image frame) {
int width = frame.width();
int height = frame.height();
for (int i = 0; i < width; i++) {
for (int j = 0; j < height; j++) {
Color c1 = frame.get(i, j);
double greyScale = (double) ((Color.red *.3) + (Color.green *.59) + (Color.blue * .11));
Color newGrey = Color.greyScale(greyScale);
frame.set(i, j, newGrey);
}
}
boolean shouldStop = displayImage(frame);
return shouldStop;
}

I'm going to try to stick as close as possible to what you already have. So, I'll assume that you are looking for how to do pixel-level processing on an Image, rather than just looking for a technique that happens to work for converting to greyscale.
The first step is that you need the image to be a BufferedImage. This is what you get by default from ImageIO, but if you have some other type of image, you can create a BufferedImage and paint the other image into it first:
BufferedImage buffer = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g = buffer.createGraphics();
g.drawImage(image, 0, 0);
g.dispose()
Then, you can operate on the pixels like this:
public void makeGrey(BufferedImage image) {
for(int x = 0; x < image.getWidth(); ++x) {
for(int y = 0; y < image.getHeight(); ++y) {
Color c1 = new Color(image.getRGB(x, y));
int grey = (int)(c1.getRed() * 0.3
+ c1.getGreen() * 0.59
+ c1.getBlue() * .11
+ .5);
Color newGrey = new Color(grey, grey, grey);
image.setRGB(x, y, newGrey.getRGB());
}
}
}
Note that this code is horribly slow. A much faster option is to extract all the pixels from the BufferedImage into an int[], operate on that, and then set it back into the image. This uses the other versions of the setRGB()/getRGB() methods that you'll find in the javadoc.

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);
}
}
}