diff --git a/core/src/main/java/net/momirealms/craftengine/core/pack/AbstractPackManager.java b/core/src/main/java/net/momirealms/craftengine/core/pack/AbstractPackManager.java
index cc0be3102..e43115a29 100644
--- a/core/src/main/java/net/momirealms/craftengine/core/pack/AbstractPackManager.java
+++ b/core/src/main/java/net/momirealms/craftengine/core/pack/AbstractPackManager.java
@@ -43,6 +43,7 @@ import org.yaml.snakeyaml.Yaml;
 import org.yaml.snakeyaml.scanner.ScannerException;
 
 import javax.imageio.ImageIO;
+import javax.imageio.ImageReader;
 import java.awt.image.BufferedImage;
 import java.io.*;
 import java.nio.charset.StandardCharsets;
@@ -1150,6 +1151,9 @@ public abstract class AbstractPackManager implements PackManager {
     private byte[] optimizeImage(byte[] previousImageBytes) throws IOException {
         try (ByteArrayInputStream is = new ByteArrayInputStream(previousImageBytes)) {
             BufferedImage src = ImageIO.read(is);
+            if (src.getType() == BufferedImage.TYPE_CUSTOM) {
+                return previousImageBytes;
+            }
             ByteArrayOutputStream baos = new ByteArrayOutputStream();
             new PngOptimizer(src).write(baos);
             return baos.toByteArray();
diff --git a/core/src/main/java/net/momirealms/craftengine/core/util/PngOptimizer.java b/core/src/main/java/net/momirealms/craftengine/core/util/PngOptimizer.java
index 2308654ca..03e1a17b5 100644
--- a/core/src/main/java/net/momirealms/craftengine/core/util/PngOptimizer.java
+++ b/core/src/main/java/net/momirealms/craftengine/core/util/PngOptimizer.java
@@ -94,37 +94,22 @@ public class PngOptimizer {
 
     private BufferedImage convertTo8BitRGB(BufferedImage src) {
         int type = src.getType();
-        if (type == BufferedImage.TYPE_INT_ARGB ||
-                type == BufferedImage.TYPE_INT_RGB ||
-                type == BufferedImage.TYPE_BYTE_INDEXED) {
-            return src;
-        }
-
-        BufferedImage eightBitImage = new BufferedImage(
-                src.getWidth(),
-                src.getHeight(),
-                src.getColorModel().hasAlpha() ? BufferedImage.TYPE_INT_ARGB : BufferedImage.TYPE_INT_RGB
-        );
-
-        // 32 bit 位深 -> 8 bit 位深
-        if (type == BufferedImage.TYPE_4BYTE_ABGR || type == BufferedImage.TYPE_4BYTE_ABGR_PRE) {
-            for (int y = 0; y < src.getHeight(); y++) {
-                for (int x = 0; x < src.getWidth(); x++) {
-                    int rgb = src.getRGB(x, y);
-                    eightBitImage.setRGB(x, y, rgb);
-                }
-            }
+        if (type == BufferedImage.TYPE_BYTE_GRAY || type == BufferedImage.TYPE_USHORT_GRAY) {
+            BufferedImage eightBitImage = new BufferedImage(
+                    src.getWidth(),
+                    src.getHeight(),
+                    BufferedImage.TYPE_4BYTE_ABGR
+            );
+            Graphics2D g2d = eightBitImage.createGraphics();
+            g2d.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY);
+            g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
+            g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_DISABLE);
+            g2d.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY);
+            g2d.drawImage(src, 0, 0, null);
+            g2d.dispose();
             return eightBitImage;
         }
-
-        Graphics2D g2d = eightBitImage.createGraphics();
-        g2d.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY);
-        g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
-        g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_DISABLE);
-        g2d.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY);
-        g2d.drawImage(src, 0, 0, null);
-        g2d.dispose();
-        return eightBitImage;
+        return src;
     }
 
     private ImageData findBestFileStructure(BufferedImage src, ImageColorInfo info) throws IOException {
diff --git a/gradle.properties b/gradle.properties
index 5d77f81af..e89c90a04 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -39,7 +39,7 @@ zstd_version=1.5.7-4
 commons_io_version=2.20.0
 commons_lang3_version=3.19.0
 sparrow_nbt_version=0.10.6
-sparrow_util_version=0.58
+sparrow_util_version=0.60
 fastutil_version=8.5.18
 netty_version=4.1.127.Final
 joml_version=1.10.8