Merge pull request #657 from glenrobson/fix-gray-turbo

Fix gray turbo
cantaloupe-project · Jul 31, 2024 · e1a9d6d · e1a9d6d
2 parents 322f101 + bd9e6aa
commit e1a9d6d
Show file tree

Hide file tree

Showing 2 changed files with 17 additions and 1 deletion.
diff --git a/src/main/java/edu/illinois/library/cantaloupe/processor/codec/jpeg/TurboJPEGImageWriter.java b/src/main/java/edu/illinois/library/cantaloupe/processor/codec/jpeg/TurboJPEGImageWriter.java
@@ -167,6 +167,11 @@ public void write(BufferedImage image,
         image = Java2DUtil.removeAlpha(image, bgColor);
         image = Java2DUtil.convertCustomToRGB(image);
 
+        // Gray subsampling required to handle grayscale input
+        if (image.getType() == BufferedImage.TYPE_BYTE_GRAY) {
+            setSubsampling(TJ.SAMP_GRAY);
+        }
+
         try (TJCompressor tjc = new TJCompressor()) {
             tjc.setSubsamp(subsampling);
             tjc.setJPEGQuality(quality);

diff --git a/...t/java/edu/illinois/library/cantaloupe/processor/codec/jpeg/TurboJPEGImageWriterTest.java b/...t/java/edu/illinois/library/cantaloupe/processor/codec/jpeg/TurboJPEGImageWriterTest.java
@@ -164,6 +164,17 @@ public void testWriteWithBufferedImage() throws Exception {
         }
     }
 
+    @Test
+    public void testWriteWithGrayBufferedImage() throws Exception {
+        BufferedImage image = new BufferedImage(50, 50,
+                BufferedImage.TYPE_BYTE_GRAY);
+
+        try (ByteArrayOutputStream os = new ByteArrayOutputStream()) {
+            instance.write(image, os);
+            assertDimensions(os, image.getWidth(), image.getHeight());
+        }
+    }
+
     @Test
     public void testWriteWithBufferedImageWithBackgroundColor()
             throws Exception {
@@ -184,4 +195,4 @@ public void testWriteWithBufferedImageWithBackgroundColor()
         }
     }
 
-}
+}