Fit Java Image into JFrame - java

I'm trying to display an Image that is bigger than the JFrame Dimensions. If I try to resize the Image smaller, then the Image quality is lost.
If I make the Image larger, the quality is not lost. Is this normal behavior in Java image package?
I guess what I'm trying to figure out is that probably I'm doing something wrong when reducing the Image size. So does Java provide a method to automatically do this without loosing image quality?
Same behavior like JButtons, where java automatically adjusts the space occupied by a JButton in a JPanel.
bufferedImage = resize(bufImage,500,600);
ImageIcon imageIcon = new ImageIcon(bufferedImage);
resizedIMage = imageIcon.getImage();
The actual resize is below. I took it from the internet.
private static BufferedImage resize(BufferedImage image, int width, int height) {
int type = image.getType() == 0? BufferedImage.TYPE_INT_ARGB : image.getType();
BufferedImage resizedImage = new BufferedImage(width, height, type);
Graphics2D g = resizedImage.createGraphics();
g.setComposite(AlphaComposite.Src);
g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g.setRenderingHint(RenderingHints.KEY_RENDERING,
RenderingHints.VALUE_RENDER_QUALITY);
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g.drawImage(image, 0, 0, width, height, null);
g.dispose();
return resizedImage;
}

If you are using Java 5 or newer you can try RenderingHints.VALUE_INTERPOLATION_BICUBIC for your interpolation hint.
There is a very detailed description of the different scaling behaviours of Java2D in this article: perils-of-getScaledInstance
It contains examples of the different downscale results you can expect to see with the different approaches available in Java.
It also provides sample code that uses a multi-step aproach to downscale the image which appears to produce much better results than VALUE_INTERPOLATION_BILINEAR.

Override the paintComponent(Graphics g) method of whatever component will display the image and look at Graphics.drawImage()
You can even cast your Graphics instance into a Graphics2D for more functionalities. For example setRenderingHings()
Graphics2D g2 = (Graphics2D) g;
RenderingHints rh = g2.getRenderingHints ();
rh.put (RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setRenderingHints (rh);

I would get rid of this:
int type = image.getType() == 0? BufferedImage.TYPE_INT_ARGB : image.getType();
And always use BufferedImage.TYPE_INT_ARGB
That seems to give me good results.

Related

How do you simply obtain an array of pixel data from an image by java?

I need to work code to analyze the image to pixels in the form of an array.
Please help me
Paint the Image to a BufferedImage:
BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D graphics = bi.createGraphics();
graphics.drawImage(originalImage, 0, 0, null);
graphics.dispose();
Now you can use method of the BufferedImage class to manipulate the image.
Maybe using the getRGB(...) or getSubImage(...) methods?

Compare Pictures has different sizes in selenium by openCV

I am trying to include image validation in my test project, so I can validate on some ares of the website as image like teaser, footer..etc
I take a screenshot by selenium and save it as PNG file in the first time, then in every test case I will take a new screenshot and compare both of then by ShutterBug library and print the different.
The main issue that when I take a screenshot each browser has a different size and When I resize it by Graphics2D it will not be the same. I tried also with openCV but it doesn't work. because the anti-aliasing.
private static BufferedImage resize(BufferedImage img, int height, int width, int imageType) throws IOException {
Image tmp = img.getScaledInstance(width, -1, Image.SCALE_SMOOTH);
BufferedImage resized = new BufferedImage(width, height, imageType);
Graphics2D g2d = resized.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
g2d.drawImage(tmp, 0, 0, null);
g2d.dispose();
return resized;
}
private Mat resize(BufferedImage image, int height, int width){
Size size = new Size(width, height);
Mat img = Imgcodecs.imdecode(new MatOfByte(bufferedImageToByteArray(image)), Imgcodecs.IMREAD_COLOR);
Mat resized=new Mat(size,CvType.CV_64FC4);
Imgproc.resize(img, resized, size,INTER_AREA);
return resized;
}
I have tried all these options but at the end i am now using
https://github.com/newsuk/AyeSpy
Aye Spy is a high performance visual regression tool to catch UI regressions.
It's very simple and manageable.
You just need to setup selenium grid and run the json file.
It will compare perfectly and give you the comparison result like
You can try it one time.Hope it will help you to generate comparison result for testing
There are several open source solutions for comparing screenshots in the UI automation testing, which just does the same things as you are working on. I suggest you can try Micoo which is a visual testing service, self-hosted and open source. When you get used to Micoo, you will find it's quite easy to do visual testing with it, of course, compare with different size of images is not a problem at all.

Is there a way to scale an image down to a specific size?

I am currently trying to get some kind of 2D dungeoncrawler (think: roguelike) running. Now I want to work with square tiles (32x32) but I wonder if there's a way to make my textures in a higher resolution, say 64x64, and scale them down onto a 32x32 square?
I imagine there has to be since almost all games do this in one way or another but all I can seem to find online is about 3D stuff.
Yeah. When you draw an image, you can add the new width and height to it to resize it.
public static BufferedImage resizeImage(BufferedImage image, int newwidth, int newheight) {
BufferedImage image2 = new BufferedImage(newwidth, newheight, BufferedImage.TYPE_INT_ARGB);
Graphics g = image2.getGraphics();
g.drawImage(image, 0, 0, newwidth, newheight, null);
g.dispose();
return image2;
}
Refer to here for more info.

How to make a rounded corner image in Java

I want to make a image with rounded corners. A image will come from input and I will make it rounded corner then save it. I use pure java. How can I do that? I need a function like
public void makeRoundedCorner(Image image, File outputFile){
.....
}
Edit : Added an image for information.
I suggest this method that takes an image and produces an image and keeps the image IO outside:
Edit: I finally managed to make Java2D soft-clip the graphics with the help of Java 2D Trickery: Soft Clipping by Chris Campbell. Sadly, this isn't something Java2D supports out of the box with some RenderhingHint.
public static BufferedImage makeRoundedCorner(BufferedImage image, int cornerRadius) {
int w = image.getWidth();
int h = image.getHeight();
BufferedImage output = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = output.createGraphics();
// This is what we want, but it only does hard-clipping, i.e. aliasing
// g2.setClip(new RoundRectangle2D ...)
// so instead fake soft-clipping by first drawing the desired clip shape
// in fully opaque white with antialiasing enabled...
g2.setComposite(AlphaComposite.Src);
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(Color.WHITE);
g2.fill(new RoundRectangle2D.Float(0, 0, w, h, cornerRadius, cornerRadius));
// ... then compositing the image on top,
// using the white shape from above as alpha source
g2.setComposite(AlphaComposite.SrcAtop);
g2.drawImage(image, 0, 0, null);
g2.dispose();
return output;
}
Here's a test driver:
public static void main(String[] args) throws IOException {
BufferedImage icon = ImageIO.read(new File("icon.png"));
BufferedImage rounded = makeRoundedCorner(icon, 20);
ImageIO.write(rounded, "png", new File("icon.rounded.png"));
}
This it what the input/output of the above method looks like:
Input:
Ugly, jagged output with setClip():
Nice, smooth output with composite trick:
Close up of the corners on gray background (setClip() obviously left, composite right):
I am writing a follow up to Philipp Reichart's answer.
the answer of as an answer.
To remove the white background (seems to be black in the pictures), change g2.setComposite(AlphaComposite.SrcAtop);
to g2.setComposite(AlphaComposite.SrcIn);
This was a big problem for me because I have different images with transparency that I don't want to lose.
My original image:
If I use g2.setComposite(AlphaComposite.SrcAtop);:
When I use g2.setComposite(AlphaComposite.SrcIn); the background is transparent.
I found another way using TexturePaint:
ImageObserver obs = ...;
int w = img.getWidth(obs);
int h = img.getHeight(obs);
// any shape can be used
Shape clipShape = new RoundRectangle2D.Double(0, 0, w, h, 20, 20);
// create a BufferedImage with transparency
BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics2D bg = bi.createGraphics();
// make BufferedImage fully transparent
bg.setComposite(AlphaComposite.Clear);
bg.fillRect(0, 0, w, h);
bg.setComposite(AlphaComposite.SrcOver);
// copy/paint the actual image into the BufferedImage
bg.drawImage(img, 0, 0, w, h, obs);
// set the image to be used as TexturePaint on the target Graphics
g.setPaint(new TexturePaint(bi, new Rectangle2D.Float(0, 0, w, h)));
// activate AntiAliasing
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
// translate the origin to where you want to paint the image
g.translate(x, y);
// draw the Image
g.fill(clipShape);
// reset paint
g.setPaint(null);
This code can be simplified if you have a non-animated image, by creating the BufferedImage only once and keeping it for each paint.
If your image is animated though you have to recreate the BufferedImage on each paint. (Or at least i have not found a better solution for this yet.)

Custom JLabel icon

I want to use java JLabel with an Icon in custom size on my GUI. like this :
I used this code to change size of original Icon :
ImageIcon imageIcon = (ImageIcon) jLabel1.getIcon();// new ImageIcon( "Play-Hot-icon.png");
ImageIcon thumbnailIcon = new ImageIcon(getScaledImage(imageIcon.getImage(), 25 , 25));
jLabel1.setIcon(thumbnailIcon);
and here is code for resize image
private Image getScaledImage(Image srcImg, int w, int h){
BufferedImage resizedImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = resizedImg.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2.drawImage(srcImg, 0, 0, w, h, null);
g2.dispose();
return resizedImg;
}
but after resizing image and using this code the result is this! :
how can I have desired image on my JLabel??
regards,
sajad
The problem is that when you create the scaled image, you use BufferedImage.TYPE_INT_RGB for your new image, and transparency gets rendered as black with just TYPE_INT_RGB.
In order to keep transparency, you need to replace that with BufferedImage.TYPE_INT_ARGB, since you need an alpha component.
However, calling Image.getScaledInstance on imageIcon's image will return a scaled image, already with an alpha component, and you can pass it rendering hints to play with the quality of the scaled image, doing essentially the same as your getScaledImage function, but with less of the hassle.

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