Java将图像转换为BufferedImage
Java将图像转换为BufferedImage
提问于 2012-11-28 20:37:50
StackOverflow上已经有类似这样的问题了，公认的答案是"casting"：
Image image = ImageIO.read(new File(file));
BufferedImage buffered = (BufferedImage) image;在我的程序中，我尝试：
final float FACTOR = 4f;
BufferedImage img = ImageIO.read(new File("graphic.png"));
int scaleX = (int) (img.getWidth() * FACTOR);
int scaleY = (int) (img.getHeight() * FACTOR);
Image image = img.getScaledInstance(scaleX, scaleY, Image.SCALE_SMOOTH);
BufferedImage buffered = (BufferedImage) image;不幸的是，我得到了运行时错误：
无法将
sun.awt.image.ToolkitImage转换为java.awt.image.BufferedImage
显然，强制转换不起作用。
问题是:什么是(或有没有)将图像转换为BufferedImage的正确方法？
回答 4
Stack Overflow用户
回答已采纳
发布于 2012-11-28 20:47:11
/**
* Converts a given Image into a BufferedImage
*
* @param img The Image to be converted
* @return The converted BufferedImage
*/
public static BufferedImage toBufferedImage(Image img)
{
if (img instanceof BufferedImage)
{
return (BufferedImage) img;
}
// Create a buffered image with transparency
BufferedImage bimage = new BufferedImage(img.getWidth(null), img.getHeight(null), BufferedImage.TYPE_INT_ARGB);
// Draw the image on to the buffered image
Graphics2D bGr = bimage.createGraphics();
bGr.drawImage(img, 0, 0, null);
bGr.dispose();
// Return the buffered image
return bimage;
}Stack Overflow用户
发布于 2012-11-28 20:51:09
处理这种情况的一种方法是创建一个新的图形，并告诉它的BufferedImage对象将缩放的图像绘制到新的BufferedImage中：
final float FACTOR = 4f;
BufferedImage img = ImageIO.read(new File("graphic.png"));
int scaleX = (int) (img.getWidth() * FACTOR);
int scaleY = (int) (img.getHeight() * FACTOR);
Image image = img.getScaledInstance(scaleX, scaleY, Image.SCALE_SMOOTH);
BufferedImage buffered = new BufferedImage(scaleX, scaleY, TYPE);
buffered.getGraphics().drawImage(image, 0, 0 , null);这应该可以在不进行强制转换的情况下完成此操作。
Stack Overflow用户
发布于 2017-11-27 20:42:36
如果你使用Kotlin，你可以用Sri Harsha建议的相同方式向Image添加一个扩展方法。
fun Image.toBufferedImage(): BufferedImage {
if (this is BufferedImage) {
return this
}
val bufferedImage = BufferedImage(this.getWidth(null), this.getHeight(null), BufferedImage.TYPE_INT_ARGB)
val graphics2D = bufferedImage.createGraphics()
graphics2D.drawImage(this, 0, 0, null)
graphics2D.dispose()
return bufferedImage
}并像这样使用它：
myImage.toBufferedImage()页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/13605248
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