I would like to extract a rectangle of a BufferedImage.
Javadoc propose getSubImage(x,y,w,h) and getData(rectangle).
getData is cool but I don't want only the raster. I want the subimage as a BufferedImage object but I also need a modified version of it data array but the javadoc says
public BufferedImage getSubimage(int x,int y,int w,int h) : Returns a subimage defined by a specified rectangular region. The returned BufferedImage shares the same data array as the original image.
Q: how can I extract a subimage with a shrinked data array ?
Given a BufferedImage image, here's 3 ways to create a "deep" copy subimage:
// Create an image
BufferedImage image = new BufferedImage(100, 100, BufferedImage.TYPE_4BYTE_ABGR);
// Fill with static
new Random().nextBytes(((DataBufferByte) image.getRaster().getDataBuffer()).getData());
Create an image around the already deep copy of the Raster you get from getData(rect). This involves casting to WritableRaster, so it may break with some Java implementations or in the future. Should be quite fast, as you only copy the data once:
// Get sub-raster, cast to writable and translate it to 0,0
WritableRaster data = ((WritableRaster) image.getData(new Rectangle(25, 25, 50, 50))).createWritableTranslatedChild(0, 0);
// Create new image with data
BufferedImage subOne = new BufferedImage(image.getColorModel(), data, image.isAlphaPremultiplied(), null);
Another option, creating a sub image the "normal way", then copying the raster into a new image. Involves creating one sub-raster, still copies only once (and no casting):
// Get subimage "normal way"
BufferedImage subimage = image.getSubimage(25, 25, 50, 50);
// Create empty compatible image
BufferedImage subTwo = new BufferedImage(image.getColorModel(), image.getRaster().createCompatibleWritableRaster(50, 50), image.isAlphaPremultiplied(), null);
// Copy data into the new, empty image
subimage.copyData(subTwo.getRaster());
Finally, the easier route, just painting the subimage over a new empty image. Could be slightly slower, as it involves the rendering pipeline, but I think it should perform reasonably still.
// Get subimage "normal way"
BufferedImage subimage = image.getSubimage(25, 25, 50, 50);
// Create new empty image of same type
BufferedImage subThree = new BufferedImage(50, 50, image.getType());
// Draw the subimage onto the new, empty copy
Graphics2D g = subThree.createGraphics();
try {
g.drawImage(subimage, 0, 0, null);
}
finally {
g.dispose();
}
I had the same issue a long time ago, I didn't want a shared raster. The only solution I found was to create a BufferedImage that represents the sub-image, and then copy the pixels into the sub-image.
In order to have something really fast, I access directly the DataBuffer and I make array copies (line by line) using System.arraycopy()
Related
I'm writing an application that needs to work with 16-bit "5-5-5" RGB colors (that is, 5 bits for each color and one bit of padding). In order to handle these images, I am using the BufferedImage class provided by AWT. The BufferedImage class specifically allows for the usage of non-RGB color spaces by taking either a ColorModel object or a predefined image type constant - one of which is the 5-5-5 pixel format that I need.
My problem is this: the BufferedImage "setRGB()" method states in its description that color values provided are "assumed to be in the default RGB color model, TYPE_INT_ARGB, and default sRGB color space" (per the BufferedImage documentation page). No other method seems to accept values designed for different color spaces, either.
Is there a way to use my non-standard color space directly with BufferedImage, or would I have to rely on the class's internal color conversion mechanisms to handle all of my colors? (Or am I just misreading/misunderstanding something about how the class works?)
BufferedImage.TYPE_USHORT_555_RGB still uses a completely standard RGB color space (in fact, it uses sRGB), so I don't think a different color space is what you are looking for.
If you want to perform painting or other operations in Java, just use the normal methods like setRGB/getRGB() and createGraphics()/Grapics2D. Everything will be properly converted to and from the packed USHORT_555_RGB format for you.
For example:
BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_USHORT_555_RGB);
// Do some custom painting
Graphics2D g = image.createGraphics();
g.drawImage(otherImage, 0, 0, null); // image type here does not matter
g.setColor(Color.ORANGE); // Color in sRGB, but does not matter
g.fillOval(0, 0, w, h);
g.dispose();
image.setRGB(0, h/2, w, 1, new int[w]); // Silly way to create a horizontal black line at the center of the image... Don't do this, use fillRect(0, h/2, 1, w)! ;-)
// image will still be USHORT_555_RGB *internally*
However, if you have pixel data in the USHORT_555_RGB format (ie. from an external library/api/service), it may be faster and more accurate to set these values directly to the raster/databuffer. Or if you need to pass the pixel values back to the same library/api/service.
For example, using the Raster:
BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_USHORT_555_RGB);
// Some fictional API. It's assumed that data.length == w * h
short[] apiPixels = api.getPixelsUSHORT_555_RGB(w, h);
WritableRaster raster = image.getRaster();
// Set short values to image
raster.setDataElements(0, 0, w, h, apiPixels);
// Get short values from image
short[] pixels = (short[]) raster.getDataElements(0, 0, w, h, null); // TYPE_USHORT_555_RGB -> always short[]
api.setPixels(pixels, w, h); // Another fictional API
Or, alternatively, use the DataBuffer:
BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_USHORT_555_RGB);
// Some fictional API. It's assumed that data.length == w * h
short[] apiPixels = api.getPixelsUSHORT_555_RGB(w, h);
DataBufferUShort buffer = (DataBufferUShort) image.getRaster().getDataBuffer(); // TYPE_USHORT_555_RGB -> always DataBufferUShort
// Set short values to image
System.arraycopy(apiPixels, 0, buffer.getData(), 0, apiPixels.length);
// Get short values from image
api.setPixels(buffer.getData(), w, h);
In most cases it does not matter which method you use, but the first approach (using Raster only) may keep the image managed, which will make images display faster on screen from your Java process.
PS: If a different color space is really what you need (ie. the pixel array from the external library/api/service uses a different color space, and you need to view the pixels in this color space), you can create a BufferedImage in USHORT_555_RGB style with a custom color space like this:
// Either use one of the built-in color spaces, or load one from disk
ColorSpace colorSpace = ColorSpace.getInstance(ColorSpace.CS_LINEAR_RGB);
ColorSpace colorSpaceToo = new ICC_ColorSpace(ICC_Profile.getInstance(Files.newInputStream(new File("/path/to/custom_rgb_profile.icc").toPath())));
// Create a color model using your color space, TYPE_USHORT and 5/5/5 mask, no transparency
ColorModel colorModel = new DirectColorModel(colorSpace, 15, 0x7C00, 0x03E0, 0x001F, 0, false, DataBuffer.TYPE_USHORT);
// And finally, create an image from the color model and a compatible raster
BufferedImage imageToo = new BufferedImage(colorModel, colorModel.createCompatibleWritableRaster(w, h), colorModel.isAlphaPremultiplied(), null);
Just remember that as the Java2D graphics operations and setRGB/getRGB are still using sRGB, now all operations on your image will be converted back and forth between your color space and sRGB. Performance will not be as good.
I need a function/method that can mold(crop and resize) an imported (.png format) image into a circle of exact 150x150 pixels and it should keep transparency. I have searched all over internet, also I have my own code but I think its completely useless. I need this function for a code I am using to make GUI of a social-media app database.
private ImageIcon logo = new ImageIcon(getClass().getResource("/test/test200x200.png"));
toCircle(logo);
I need the code for the following function:
public ImageIcon toCircle(ImageIcon icon)
{
//code
return icon;
}
This function should convert this picture:
To this:
Create a new transparent image
Get a Graphics object from the image.
Set a clip for the graphics object.
Paint the PNG format image.
See also this answer that uses a clipped region.
An alternative approach, that might be more straight-forward to implement for this use case, is:
Create a transparent BufferedImage the size of your icon
Create Graphics2D from image, set hints for antialias
Fill a circle the size of your background circle
Draw the image on top of your circle, using AlphaComposite.SrcIn
Something like:
public Icon toCircle(ImageIcon logo) {
BufferedImage image = new BufferedImage(150, 150); // Assuming logo 150x150
Graphics2D g = image.createGraphics();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.fillOval(1, 1, 148, 148); // Leaving some room for antialiasing if needed
g.setComposite(AlphaComposite.SrcIn);
g.drawImage(logo.getImage(), 0, 0, null);
g.dispose();
return new ImageIcon(image);
}
I am trying to read a PNG image file from disk, draw some rectangles on it and save the modified image on the disk. Here's the scala code:
//l is a list of Rectangle objects of the form (x1,x2,y1,y2)
val image = ImageIO.read(sourceimage);
val graph=image.createGraphics()
graph.setColor(Color.GREEN)
l.foreach(x=>graph.draw(new java.awt.Rectangle(x.x1,x.y1,x.x2-x.x1,x.y2-x.y1)))
graph.dispose()
ImageIO.write(image,"png",new File(destimage))
The rectangles are drawn but in GREY color instead of GREEN. What am I doing wrong?
If the source image is a gray scale image, then it's unlikely that it will be capable of using any color of any sort.
Instead, you need to create a second, colored, BufferedImage and paint the original to it.
BufferedImage original = ImageIO.read(sourceimage);
BufferedImage iamge = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = image.createGraphics();
g2d.drawImage(original, 0, 0, null);
// Continue with what you have
Sorry, I have no experience with PIL, but that's how you'd do it (basically) in pure Java
So I have an assignment where I need to create a catalog.
The catalog needs to have a list, an image and a description.
My entire code works, so I have no issue with the coding as such.
I do have an issue with the image size.
How do I take care of images on a java gui program to make them all into one size when it is running.
Please let me know :D
When you read in an image, create a new BufferedImage that is the exact size that you desire, get it's Graphics object via getGraphics(), draw the original image into the new image using Graphics#drawImage(Image img, int x, int y, int width, int height, ImageObserver observer) where x and y are 0 and width and height are from the dimensions of the new image, dispose() of the Graphics object, and then display the new Image as an ImageIcon in a JLabel. Make sure though that the original image is the same size or larger than the new one, else your images will look gawd-awful.
For example, and note that this code may not be exactly correct since I don't have my IDE up:
BufferedImage originalImage = ImageIO.read(something); // read in original image
// create new empty image of desired size
BufferedImage newImage = new BufferedImage(desiredWidth, desiredHeight, BufferedImage.TYPE_INT_ARGB);
Graphics g = newImage.getGraphics(); // get its graphics object
// draw old image into new image
g.drawImage(originalImage, 0, 0, desiredWidth, desiredHeight, null);
g.dispose(); // get rid of Graphics object
// create ImageIcon and put in JLabel to display
Icon newIcon = new ImageIcon(newImage);
myJLabel.setIcon(newIcon);
I would propably create a JPanel to draw on one Image, and then work with the method:
myPanel.setSize(new Dimension(x,y))
or
myPanel.setPreferredSize(new Dimension....)
There is a method (image = imgobj.getScaledInstance(width, height, hints)) in awt.Image class which provides re-sizing capabilities very nicely, I always use this to re-size my images when I need. Please see here some examples :-), I hope it will work for you, it is the most convenient way to scale images I have ever seen. create a method pass the image to the method and size of the image you want and return the image back in return to reuse the code ;)
I'm currently turning an array of pixel values (originally created with a java.awt.image.PixelGrabber object) into an Image object using the following code:
public Image getImageFromArray(int[] pixels, int width, int height) {
MemoryImageSource mis = new MemoryImageSource(width, height, pixels, 0, width);
Toolkit tk = Toolkit.getDefaultToolkit();
return tk.createImage(mis);
}
Is it possible to achieve the same result using classes from the ImageIO package(s) so I don't have to use the AWT Toolkit?
Toolkit.getDefaultToolkit() does not seem to be 100% reliable and will sometimes throw an AWTError, whereas the ImageIO classes should always be available, which is why I'm interested in changing my method.
You can create the image without using ImageIO. Just create a BufferedImage using an image type matching the contents of the pixel array.
public static Image getImageFromArray(int[] pixels, int width, int height) {
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
WritableRaster raster = (WritableRaster) image.getData();
raster.setPixels(0,0,width,height,pixels);
return image;
}
When working with the PixelGrabber, don't forget to extract the RGBA info from the pixel array before calling getImageFromArray. There's an example of this in the handlepixelmethod in the PixelGrabber javadoc. Once you do that, make sure the image type in the BufferedImage constructor to BufferedImage.TYPE_INT_ARGB.
Using the raster I got an ArrayIndexOutOfBoundsException even when I created the BufferedImage with TYPE_INT_ARGB. However, using the setRGB(...) method of BufferedImage worked for me.
JavaDoc on BufferedImage.getData() says: "a Raster that is a copy of the image data."
This code works for me but I doubt in it's efficiency:
// Получаем картинку из массива.
int[] pixels = new int[width*height];
// Рисуем диагональ.
for (int j = 0; j < height; j++) {
for (int i = 0; i < width; i++) {
if (i == j) {
pixels[j*width + i] = Color.RED.getRGB();
}
else {
pixels[j*width + i] = Color.BLUE.getRGB();
//pixels[j*width + i] = 0x00000000;
}
}
}
BufferedImage pixelImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
pixelImage.setRGB(0, 0, width, height, pixels, 0, width);
I've had good success using java.awt.Robot to grab a screen shot (or a segment of the screen), but to work with ImageIO, you'll need to store it in a BufferedImage instead of the memory image source. Then you can call one static method of ImageIO and save the file. Try something like:
// Capture whole screen
Rectangle region = new Rectangle(Toolkit.getDefaultToolkit().getScreenSize());
BufferedImage capturedImage = new Robot().createScreenCapture(region);
// Save as PNG
File imageFile = new File("capturedImage.png");
ImageIO.write(capturedImage, "png", imageFile);
As this is one of the highest voted question tagged with ImageIO on SO, I think there's still room for a better solution, even if the question is old. :-)
Have a look at the BufferedImageFactory.java class from my open source imageio project at GitHub.
With it, you can simply write:
BufferedImage image = new BufferedImageFactory(image).getBufferedImage();
The other good thing is that this approach, as a worst case, has about the same performance (time) as the PixelGrabber-based examples already in this thread. For most of the common cases (typically JPEG), it's about twice as fast. In any case, it uses less memory.
As a side bonus, the color model and pixel layout of the original image is kept, instead of translated to int ARGB with default color model. This might save additional memory.
(PS: The factory also supports subsampling, region-of-interest and progress listeners if anyone's interested. :-)
I had the same problem of everyone else trying to apply the correct answer of this question, my int array actually get an OutOfboundException where i fixed it adding one more index because the length of the array has to be widht*height*3 after this i could not get the image so i fixed it setting the raster to the image
public static Image getImageFromArray(int[] pixels, int width, int height) {
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
WritableRaster raster = (WritableRaster) image.getData();
raster.setPixels(0,0,width,height,pixels);
image.setData(raster);
return image;
}
And you can see the image if u show it on a label on a jframe like this
JFrame frame = new JFrame();
frame.getContentPane().setLayout(new FlowLayout());
frame.getContentPane().add(new JLabel(new ImageIcon(image)));
frame.pack();
frame.setVisible(true);
setting the image on the imageIcon().
Last advice you can try to change the Bufferedimage.TYPE_INT_ARGB to something else that matches the image you got the array from this type is very important i had an array of 0 and -1 so I used this type BufferedImage.TYPE_3BYTE_BGR