1.23

Author: MORIMORI0317

build.gradle

@@ -6,7 +6,7 @@ plugins {
 
 group 'dev.felnull'
 archivesBaseName = "felnull-java-library"
-version '1.22'
+version '1.23'
 
 repositories {
     mavenCentral()

src/main/java/dev/felnull/fnjl/BuildIn.java

@@ -1,7 +1,7 @@
 package dev.felnull.fnjl;
 
 public class BuildIn {
-    protected static final String VERSION = "1.22";
+    protected static final String VERSION = "1.23";
 
     protected static final int NATIVE_LIB_VERSION = 2;
 }

src/main/java/dev/felnull/fnjl/util/FNImageUtil.java

@@ -96,4 +96,43 @@ public static void inputToOutputStream(InputStream in, OutputStream out) throws
             out.write(buffer, 0, len);
         }
     }
+
+    /**
+     * バイト配列が画像かどうか
+     *
+     * @param data 検体
+     * @return 画像かどうか
+     */
+    public static boolean isImage(byte[] data) {
+        try {
+            ImageIO.read(new ByteArrayInputStream(data));
+            return true;
+        } catch (IOException e) {
+            return false;
+        }
+    }
+
+    /**
+     * 画像を指定サイズまで縮小する
+     *
+     * @param image 対象画像
+     * @param size  サイズ
+     * @return 縮小済み
+     * @throws IOException exception
+     */
+    public static BufferedImage reductionSize(BufferedImage image, long size) throws IOException {
+        long lastSize = toByteArray(image, "png").length;
+        if (lastSize <= size) return image;
+        float scale = (float) size / lastSize;
+        BufferedImage nimg = resize(image, (int) (image.getWidth() * scale), (int) (image.getHeight() * scale));
+        return reductionSizeW(nimg, size, lastSize);
+    }
+
+    private static BufferedImage reductionSizeW(BufferedImage image, long size, long lastSize) throws IOException {
+        byte[] data = toByteArray(image, "png");
+        if (data.length == lastSize) throw new IOException("Can't be smaller than this");
+        if (data.length <= size) return image;
+        BufferedImage nimg = resize(image, image.getWidth() / 2, image.getHeight() / 2);
+        return reductionSizeW(nimg, size, data.length);
+    }
 }

src/test/java/dev/felnull/TestMain.java

@@ -1,10 +1,18 @@
 package dev.felnull;
 
-import dev.felnull.fnjl.util.FNMath;
+import dev.felnull.fnjl.util.FNImageUtil;
+import dev.felnull.fnjl.util.FNStringUtil;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.File;
 
 public class TestMain {
     public static void main(String[] args) throws Exception {
-        System.out.println(FNMath.scale(512, 1024));
+        System.out.println(FNStringUtil.getByteDisplay(1000 * 1000));
+        BufferedImage img = FNImageUtil.reductionSize(ImageIO.read(new File("V:\\dev\\java\\FelNullJavaLibrary\\test\\t.png")), 1000 * 1000);
+        ImageIO.write(img, "png", new File("V:\\dev\\java\\FelNullJavaLibrary\\test\\t2.png"));
+        //System.out.println(FNMath.scale(512, 1024));
       /*  long time = System.currentTimeMillis();
         FNRuntimeUtil.multipleRun("Ikisugi", 2, () -> {
             try {