Java9 多分辨率图像 API
在Java 9中，引入了一个新的多分辨率图像 API，支持具有不同分辨率变体的多个图像。此 API 允许一组具有不同分辨率的图像作为单个多分辨率图像使用。以下是多分辨率图像的主要操作。
Image getResolutionVariant(double destImageWidth, double destImageHeight) − 获取此逻辑图像在指定大小上最佳变体的特定图像。
List <Image> getResolutionVariants() − 获取所有分辨率变体的可读列表。
示例
import java.io.IOException;import java.net.URL;import java.net.MalformedURLException;import java.util.ArrayList;import java.util.List;import java.awt.Image;import java.awt.image.MultiResolutionImage;import java.awt.image.BaseMultiResolutionImage;import javax.imageio.ImageIO;public class Tester { public static void main(String[] args) throws IOException, MalformedURLException { List<String> imgUrls = List.of("http://www.tutorialspoint.com/java9/images/logo.png", "http://www.tutorialspoint.com/java9/images/mini_logo.png", "http://www.tutorialspoint.com/java9/images/large_logo.png"); List<Image> images = new ArrayList<Image>(); for (String url : imgUrls) { images.add(ImageIO.read(new URL(url))); } // read all images into one multiresolution image MultiResolutionImage multiResolutionImage = new BaseMultiResolutionImage(images.toArray(new Image[0])); // get all variants of images List<Image> variants = multiResolutionImage.getResolutionVariants(); System.out.println("Total number of images: " + variants.size()); for (Image img : variants) { System.out.println(img); } // get a resolution-specific image variant for each indicated size Image variant1 = multiResolutionImage.getResolutionVariant(156, 45); System.out.printf("\nImage for destination[%d,%d]: [%d,%d]", 156, 45, variant1.getWidth(null), variant1.getHeight(null)); Image variant2 = multiResolutionImage.getResolutionVariant(311, 89); System.out.printf("\nImage for destination[%d,%d]: [%d,%d]", 311, 89, variant2.getWidth(null), variant2.getHeight(null)); Image variant3 = multiResolutionImage.getResolutionVariant(622, 178); System.out.printf("\nImage for destination[%d,%d]: [%d,%d]", 622, 178, variant3.getWidth(null), variant3.getHeight(null)); Image variant4 = multiResolutionImage.getResolutionVariant(300, 300); System.out.printf("\nImage for destination[%d,%d]: [%d,%d]", 300, 300, variant4.getWidth(null), variant4.getHeight(null)); } }
输出
Total number of images: 3BufferedImage@7ce6a65d: type = 6 ColorModel: #pixelBits = 32 numComponents = 4 color space =java.awt.color.ICC_ColorSpace@548ad73b transparency = 3 has alpha = true isAlphaPre = false ByteInterleavedRaster: width =311 height = 89 #numDataElements 4 dataOff[0] = 3BufferedImage@4c762604: type = 6 ColorModel: #pixelBits = 32 numComponents = 4 color space =java.awt.color.ICC_ColorSpace@548ad73b transparency = 3 has alpha = true isAlphaPre = false ByteInterleavedRaster: width =156 height = 45 #numDataElements 4 dataOff[0] = 3BufferedImage@2641e737: type = 6 ColorModel: #pixelBits = 32 numComponents = 4 color space =java.awt.color.ICC_ColorSpace@548ad73b transparency = 3 has alpha = true isAlphaPre = false ByteInterleavedRaster: width =622 height = 178 #numDataElements 4 dataOff[0] = 3Image for destination[156,45]: [311,89]Image for destination[311,89]: [311,89]Image for destination[622,178]: [622,178]Image for destination[300,300]: [622,178]
