ImageUtil for EPWING

- Bump EB4j@2.3.0
- Use ImageUtil in EB4j
- Refactoring ImageUtils

Signed-off-by: Hiroshi Miura <miurahr@linux.com>

build.gradle.kts

@@ -68,7 +68,7 @@ repositories {
 }
 
 dependencies {
-    implementation("io.github.eb4j:eb4j:2.2.2")
+    implementation("io.github.eb4j:eb4j:2.3.0")
     implementation("org.slf4j:slf4j-simple:1.7.32")
 
     implementation("commons-io:commons-io:2.11.0")

src/main/java/io/github/eb4j/ebview/dictionary/epwing/EBDictStringHook.java

@@ -4,6 +4,7 @@
 import io.github.eb4j.GraphicData;
 import io.github.eb4j.SoundData;
 import io.github.eb4j.SubBook;
+import io.github.eb4j.ebview.utils.ImageUtils;
 import io.github.eb4j.hook.Hook;
 import io.github.eb4j.hook.HookAdapter;
 import io.github.eb4j.util.ImageUtil;
@@ -305,7 +306,7 @@ public void endMonoGraphic(final long pos) {
         try {
             byte[] bytes = graphicData.getMonoGraphic(pos, lastWidth, lastHeight);
             output.append("\" src=\"data:image/png;base64,");
-            output.append(Utils.convertMonoGraphic2Base64(bytes, lastWidth, lastHeight)).append("\"/>");
+            output.append(ImageUtils.convertMonoGraphic2Base64(bytes, lastWidth, lastHeight)).append("\"/>");
         } catch (EBException | IOException e) {
             e.printStackTrace();
         }
@@ -317,12 +318,12 @@ public void beginInlineColorGraphic(final int format, final long pos) {
             byte[] bytes = graphicData.getColorGraphic(pos);
             if (format == Hook.JPEG) {
                 output.append("<img src=\"data:image/jpeg;base64,");
-                output.append(Utils.convertImage2Base64("jpeg", bytes));
+                output.append(ImageUtils.convertImage2Base64("jpeg", bytes));
                 output.append("\" alt=\"");
             } else {
                 bytes = ImageUtil.dibToPNG(bytes);
                 output.append("<img src=\"data:image/png;base64,");
-                output.append(Utils.convertImage2Base64("png", bytes));
+                output.append(ImageUtils.convertImage2Base64("png", bytes));
                 output.append("\" alt=\"");
             }
         } catch (EBException | IOException e) {

src/main/java/io/github/eb4j/ebview/dictionary/epwing/Gaiji.java

@@ -4,6 +4,7 @@
 import io.github.eb4j.ExtFont;
 import io.github.eb4j.SubAppendix;
 import io.github.eb4j.SubBook;
+import io.github.eb4j.ebview.utils.ImageUtils;
 import io.github.eb4j.ext.UnicodeMap;
 import io.github.eb4j.util.HexUtil;
 import org.apache.commons.lang3.StringUtils;
@@ -91,7 +92,7 @@ public String getAltCode(final int code, final boolean narrow) {
 
     private String convertImage(final byte[] data, final int width, final int height) throws IOException {
         StringBuilder sb = new StringBuilder("<img src=\"data:image/png;base64,");
-        sb.append(Utils.convertMonoGraphic2Base64(data, width, height));
+        sb.append(ImageUtils.convertMonoGraphic2Base64(data, width, height));
         sb.append("\"/>");
         return sb.toString();
     }

src/main/java/io/github/eb4j/ebview/utils/ImageUtils.java

@@ -0,0 +1,49 @@
+package io.github.eb4j.ebview.utils;
+
+import io.github.eb4j.util.ImageUtil;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.Base64;
+
+
+public final class ImageUtils {
+    private ImageUtils() {
+    }
+
+    /**
+     * convert image data to base64.
+     * @param format image format.
+     * @param data image data
+     * @return base64 string
+     * @throws IOException when conversion failed
+     */
+    public static String convertImage2Base64(final String format, final byte[] data) throws IOException {
+        byte[] bytes;
+        Base64.Encoder base64Encoder = Base64.getEncoder();
+        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
+            final BufferedImage res = ImageIO.read(new ByteArrayInputStream(data));
+            ImageIO.write(res, format, baos);
+            baos.flush();
+            bytes = baos.toByteArray();
+        }
+        return base64Encoder.encodeToString(bytes);
+    }
+
+    /**
+     * Convert eb_bitmap to PNG, and convert to Base64 String.
+     *
+     * @param data  eb_bitmap font data
+     * @param width  image width
+     * @param height image height
+     * @return String Base64 encoded PNG data.
+     * @throws IOException when the image is broken or caused error.
+     */
+    public static String convertMonoGraphic2Base64(final byte[] data, final int width, final int height)
+            throws IOException {
+        return convertImage2Base64("png", ImageUtil.ebBitmap2BMP(data, width, height));
+    }
+}

src/test/java/io/github/eb4j/ebview/dictionary/epwing/GaijiTest.java

@@ -1,5 +1,6 @@
 package io.github.eb4j.ebview.dictionary.epwing;
 
+import io.github.eb4j.ebview.utils.ImageUtils;
 import org.junit.jupiter.api.Test;
 
 import java.io.IOException;
@@ -14,7 +15,7 @@ public void convertImageTest() throws IOException {
         byte[] data = new byte[] {0x00, 0x00, 0x00, 0x00, 0x00, (byte) 0xe0, 0x03, (byte) 0x80, 0x00,
                 0x00, 0x00, 0x00, 0x03, (byte) 0xc0, 0x04, 0x20, 0x00, 0x20, 0x00,
                 (byte) 0xe0, 0x03, 0x20, 0x04, 0x20, 0x04, 0x60, 0x03, (byte) 0xa0, 0x00, 0x00, 0x00, 0x00};
-        String image = Utils.convertMonoGraphic2Base64(data, 16, 16);
+        String image = ImageUtils.convertMonoGraphic2Base64(data, 16, 16);
         assertEquals("iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAQMAAAAlPW0iAAAABlBMVEX///8AAABVwtN+AAAAKklEQVR4Xm"
                         + "NggIAHzMz8EBYj815GFhmmPwxMDAcYmWWZGIEMB6b/DhBZAHKDBT9OJvDqAAAAAElFTkSuQmCC", image);
     }