Hi everyone i have problems in converting GrayScale bmp images into integer 2D-array (with values 0-255) in Java.
I have a pmb image that could be seen as an integer(0-255) 2D-array and i want to see that 2D-array in a Java data structure
i tried this way:
Image image = ImageIO.read(new File("my_img.bmp"));
BufferedImage img = new BufferedImage(image.getWidth(null), image.getHeight(null), BufferedImage.TYPE_BYTE_GRAY);
Graphics g = img.createGraphics();
g.drawImage(image, 0, 0, null);
g.dispose();
Then with my BufferedImage i create int[][] this way:
int w = img.getWidth();
int h = img.getHeight();
int[][] array = new int[w][h];
for (int j = 0; j < w; j++) {
for (int k = 0; k < h; k++) {
array[j][k] = img.getRGB(j, k);
}
}
But now all the 2D-array is full of number like "-9211021" or similar.
i think that the problem is in getRGB(j,k) but i don't know if it's possible to solve it.
edit:
i know RGB is not grayscale, so how can i get the grayscale value of a single pixel from a grayscale BufferedImage?
In a grayscale image, BufferedImage.getPixel(x,y) wont give values within the [0-255] range. Instead, it returns the corresponding value of a gray level(intensity) in the RGB colorspace. That's why you are getting values like "-9211021".
The following snippet should solve your problem :
Raster raster = image.getData();
for (int j = 0; j < w; j++) {
for (int k = 0; k < h; k++) {
array[j][k] = raster.getSample(j, k, 0);
}
}
where image is the created BufferedImage. The 0 in the getSample indicates that we are accessing the first byte/band(setting it to a greater value will throw a ArrayOutOfBoundException in grayscale images).
You can use Catalano Framework. Contains several filters for image processing.
http://code.google.com/p/catalano-framework/
Detail: That's it faster than using WritableRaster.
FastBitmap fb = new FastBitmap(bufferedImage);
int[][] image = new int[fb.getHeight()][fb.getWidth];
fb.toArrayGray(image);
//Do manipulations with image
//...
//Place the image into fastBitmap
fb.arrayToImage(image);
//Retrieve in bufferedImage if you desire.
bufferedImage = fb.toBufferedImage();
Related
I have an arary of double value (or can be float values as well). The range of the values are between 0-255. The array is in shape of [128][128][3], thus a RGB array of image. Now I want save this array as image (png or jpg). How this can be done in Java?
Ok, finally I could understand the image in Java.
after having an array of int[][][] nwimage = new int[128][128][3], convert all values from the float array to integer. The float array has shape of [128][128][3] as well.
now create a buffered image with the shape of nwimage as 2D which is 128x128.
BufferedImage bfImage = new BufferedImage(128, 128, BufferedImage.TYPE_INT_RGB);
now setRGB for each index of the bfImage as below;
for(int i = 0; i < 128; i++) {
for(int j = 0; j < 128; j++) {
Color myRGB = new Color(nwimage[i][j][0], nwimage[i][j][1], nwimage[i][j][2]);
int rgb = myRGB.getRGB();
bfImage.setRGB(i, j, rgb);
}
}
So after hours of searching I am ready to pull my hair out on this one.
I am doing some research in Computer Vision and am working with grayscale images. I need to end up with an "image" (a double scripted double array) of Sobel filtered double values. My Sobel converter is set up to take in a double scripted int array (int[][]) and go from there.
I am reading in a buffered image and I gather the grayscale int values via a method that I am 99% sure works perfectly (I can present it if need be).
Next I am attempting to convert this matrix of int values to a BufferedImage by the below method:
private BufferedImage getBIFromIntArr(int[][] matrix){
BufferedImage img = new BufferedImage(matrix.length * 4, matrix[0].length, BufferedImage.TYPE_INT_ARGB);
- Gather the pixels in the form of [alpha, r, g, b]
- multiply the size of the array by 4 for the model
int[] pixels = new int[(matrix.length * 4 * matrix[0].length)];
int index = 0;
for (int i = 0; i < matrix.length; i++) {
for (int j = 0; j < matrix[0].length; j++) {
int pixel = matrix[i][j];
pixels[index] = pixel;
index++;
for (int k = 0; k < 3; k++) {
pixels[index] = 0;
index++;
}
}
}
-get the raster
WritableRaster raster = img.getRaster();
-output the amount of pixels and a sample of the array
System.out.println(pixels.length);
for (int i = 0; i < pixels.length; i++) {
System.out.print(pixels[i] + " ");
}
- set the pixels of the raster
raster.setPixels(0, 0, matrix.length, matrix[0].length, pixels);
- paint the image via an external routing to check works (does not)
p.panel.setNewImage(img);
return img;
}
Here is my understanding. The ARGB Type consists of 4 values Alpha, Red, Green, and Blue. I am guessing that setting the alpha values in the new BufferedImage to the greyscale image int values (the matrix values passed in) then this will reproduce the image. Please correct me if I am wrong. So as you can see I create an array of pixels that stores the int values like this: [intValue, 0, 0, 0] repeatedly to try to stay with the 4 value model.
Then I create a writable raster and set the gathered pixels in it using the gathered pixels. The only thing is that I get nothing in the BufferedImage. No error with the code below and Im sure my indeces are correct.
What am I doing wrong? Im sure it is obvious but any help is appreciated because I cant see it. Perhaps my assumption about the model is wrong?
Thanks,
Chronic
I have an array called image[][] and i want to create a BufferedImage out of this so I can have the player store it in a file.
// Initialize Color[][] however you were already doing so.
Color[][] image;
// Initialize BufferedImage, assuming Color[][] is already properly populated.
BufferedImage bufferedImage = new BufferedImage(image.length, image[0].length,
BufferedImage.TYPE_INT_RGB);
// Set each pixel of the BufferedImage to the color from the Color[][].
for (int x = 0; x < image.length; x++) {
for (int y = 0; y < image[x].length; y++) {
bufferedImage.setRGB(x, y, image[x][y].getRGB());
}
}
This is a straightforward way of creating (and potentially storing) an image, if that's what you're trying to get at. However, this is not efficient by any means. Try it with a larger image and you'll see a noticeable speed difference.
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.
I'm creating a simple program which accepts a gray scale image as an input and what I simply want to do is retrieve the color information of each pixel, store it in an array of objects I call PixelClass. The ultimate goal is simply to repaint the image to a new BufferedImage using the said acquired color information.
Code used to create the pixel array from a given image.
public static PixelClass[][] getPixelArray(BufferedImage bi){
int height = bi.getHeight();
int width = bi.getWidth();
PixelClass[][] pixelArray = new PixelClass[height][width];
for(int i = 0 ; i < height ; i++){
for(int j = 0 ; j < width ; j++){
pixelArray [i] [j] = new PixelClass(bi.getRGB(j, i));
}
}
return pixelArray;
}
Code used to attempt to repaint the said image, using the array of PixelClass objects
public void paintToPanel(PixelClass [][] pc, int height, int width){
BufferedImage nbi = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
for ( int i = 0 ; i < height ; i++){
for ( int j = 0 ; j < width ; j++){
nbi.setRGB(j, i, pc[i][j].getRGBValue());
}
}
JLabel containerLabel = new JLabel(new ImageIcon(nbi));
containerLabel.setBounds(10,10,nbi.getHeight(), nbi.getWidth());
this.add(containerLabel);
}
Links to original images
http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs1364.snc4/163667_172099429501181_100001033756527_413302_3062182_n.jpg
As you can see there is significant degradation on the quality of the image. The resulting image appear to be faded.
I would suggest you use the MemoryImageSource class. Something like :
byte[] pixels = // your pixels
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY);
int bits[] = new int[] {8};
ColorModel cm = new ComponentColorModel(cs, bits, false, false, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
MemoryImageSource mis = new MemoryImageSource(width, height, cm, pixels, 0, width);
Image im = Toolkit.getDefaultToolkit().createImage(mis);