Devo ridimensionare un'immagine, utilizzo il seguente codice che funziona ma mi cambia i colori dell'imamgine
(l'immagine di partenza è un file jpg 640*480 con colori grigio e azzurro e mi ritrovo un'immagine 150*112 rossastra
Se non la ridimensiono i colori sono corretti, quindi è nel metodo getScaledInstance che c'è qualche problema.
sapete aiutarmi?
codice:
int newWidth = 150;
int newHeight = 112;
Image image = ImageUtil.getImageFromFile(fileImmagine);
Image resizedImage = image.getScaledInstance(newWidth, newHeight, Image.SCALE_SMOOTH);
BufferedImage bufferedResizedImage = ImageUtil.toBufferedImage(resizedImage);
ImageUtil.saveImage(bufferedResizedImage, nomeImmagineModificato,
Constants.IMAGES_THUMB_PATH);
codice:
public static Image getImageFromFile(File file) throws IOException {
Image image = ImageIO.read(file);
return image;
}
// This method returns a buffered image with the contents of an image
public static BufferedImage toBufferedImage(Image image) {
if (image instanceof BufferedImage) {
return (BufferedImage) image;
}
// This code ensures that all the pixels in the image are loaded
image = new ImageIcon(image).getImage();
// Determine if the image has transparent pixels; for this method's
// implementation, see e661 Determining If an Image Has Transparent
// Pixels
boolean hasAlpha = hasAlpha(image);
// Create a buffered image with a format that's compatible with the
// screen
BufferedImage bimage = null;
GraphicsEnvironment ge = GraphicsEnvironment
.getLocalGraphicsEnvironment();
try {
// Determine the type of transparency of the new buffered image
int transparency = Transparency.OPAQUE;
if (hasAlpha) {
transparency = Transparency.BITMASK;
}
// Create the buffered image
GraphicsDevice gs = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gs.getDefaultConfiguration();
bimage = gc.createCompatibleImage(image.getWidth(null), image
.getHeight(null), transparency);
} catch (HeadlessException e) {
// The system does not have a screen
}
if (bimage == null) {
// Create a buffered image using the default color model
int type = BufferedImage.TYPE_INT_RGB;
if (hasAlpha) {
type = BufferedImage.TYPE_INT_ARGB;
}
bimage = new BufferedImage(image.getWidth(null), image
.getHeight(null), type);
}
// Copy image to buffered image
Graphics g = bimage.createGraphics();
// Paint the image onto the buffered image
g.drawImage(image, 0, 0, null);
g.dispose();
return bimage;
}
// This method returns true if the specified image has transparent pixels
public static boolean hasAlpha(Image image) {
// If buffered image, the color model is readily available
if (image instanceof BufferedImage) {
BufferedImage bimage = (BufferedImage) image;
return bimage.getColorModel().hasAlpha();
}
// Use a pixel grabber to retrieve the image's color model;
// grabbing a single pixel is usually sufficient
PixelGrabber pg = new PixelGrabber(image, 0, 0, 1, 1, false);
try {
pg.grabPixels();
} catch (InterruptedException e) {
}
// Get the image's color model
ColorModel cm = pg.getColorModel();
return cm.hasAlpha();
}