Hello I have a QR code Image , and I want to resize it , when I try to resize it to a small image using this code , I always get a blury image , and the QR code is no longer valid when I scan it , but it works fine when I resize to a big sized images with the same code :
public BufferedImage getScaledInstance(BufferedImage img,
int targetWidth,
int targetHeight,
Object hint,
boolean higherQuality)
{
int type = (img.getTransparency() == Transparency.OPAQUE) ?
BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB;
BufferedImage ret = (BufferedImage)img;
int w, h;
if (higherQuality) {
// Use multi-step technique: start with original size, then
// scale down in multiple passes with drawImage()
// until the target size is reached
w = img.getWidth();
h = img.getHeight();
} else {
// Use one-step technique: scale directly from original
// size to target size with a single drawImage() call
w = targetWidth;
h = targetHeight;
}
do {
if (higherQuality && w > targetWidth) {
w /= 2;
if (w < targetWidth) {
w = targetWidth;
}
}
if (higherQuality && h > targetHeight) {
h /= 2;
if (h < targetHeight) {
h = targetHeight;
}
}
BufferedImage tmp = new BufferedImage(w, h, type);
Graphics2D g2 = tmp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, hint);
// g2.setRenderingHint(RenderingHints.KEY_DITHERING, hint);
g2.drawImage(ret, 0, 0, w, h, null);
g2.dispose();
ret = tmp;
} while (w != targetWidth || h != targetHeight);
return ret;
}
what is the problem , I don't exactly understand , please give me at least a hint , thank you
One of the simplest ways to resize an image in the HTML is using the height and width attributes on the img tag. These values specify the height and width of the image element. The values are set in px i.e. CSS pixels.
I use affine transformation to achieve this task, here is my code, hope it helps
/**
* scale image
*
* @param sbi image to scale
* @param imageType type of image
* @param dWidth width of destination image
* @param dHeight height of destination image
* @param fWidth x-factor for transformation / scaling
* @param fHeight y-factor for transformation / scaling
* @return scaled image
*/
public static BufferedImage scale(BufferedImage sbi, int imageType, int dWidth, int dHeight, double fWidth, double fHeight) {
BufferedImage dbi = null;
if(sbi != null) {
dbi = new BufferedImage(dWidth, dHeight, imageType);
Graphics2D g = dbi.createGraphics();
AffineTransform at = AffineTransform.getScaleInstance(fWidth, fHeight);
g.drawRenderedImage(sbi, at);
}
return dbi;
}
Based on @A4L's answer:
A more straigt forward version. Also his solution did only scale the canvas not the image itself.
public static BufferedImage scale(BufferedImage imageToScale, int dWidth, int dHeight) {
BufferedImage scaledImage = null;
if (imageToScale != null) {
scaledImage = new BufferedImage(dWidth, dHeight, imageToScale.getType());
Graphics2D graphics2D = scaledImage.createGraphics();
graphics2D.drawImage(imageToScale, 0, 0, dWidth, dHeight, null);
graphics2D.dispose();
}
return scaledImage;
}
to increase the quality you could add
graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
graphics2D.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With