codec: add a null check in ImageIOJPEGImageWriter, other small impr…

…ovements

echosvg-codec/src/main/java/io/sf/carte/echosvg/ext/awt/image/codec/imageio/ImageIOImageWriter.java

@@ -59,19 +59,11 @@ public ImageIOImageWriter(String mime) {
 		this.targetMIME = mime;
 	}
 
-	/**
-	 * @see ImageWriter#writeImage(java.awt.image.RenderedImage,
-	 *      java.io.OutputStream)
-	 */
 	@Override
 	public void writeImage(RenderedImage image, OutputStream out) throws IOException {
 		writeImage(image, out, null);
 	}
 
-	/**
-	 * @see ImageWriter#writeImage(java.awt.image.RenderedImage,
-	 *      java.io.OutputStream, ImageWriterParams)
-	 */
 	@Override
 	public void writeImage(RenderedImage image, OutputStream out, ImageWriterParams params) throws IOException {
 		Iterator<javax.imageio.ImageWriter> iter = ImageIO.getImageWritersByMIMEType(getMIMEType());

echosvg-codec/src/main/java/io/sf/carte/echosvg/ext/awt/image/codec/imageio/ImageIOJPEGImageWriter.java

@@ -127,13 +127,16 @@ private static IIOMetadata addAdobeTransform(IIOMetadata meta) {
 	protected ImageWriteParam getDefaultWriteParam(ImageWriter iiowriter, RenderedImage image,
 			ImageWriterParams params) {
 		JPEGImageWriteParam param = new JPEGImageWriteParam(iiowriter.getLocale());
-		param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
-		param.setCompressionQuality(params.getJPEGQuality());
-		if (params.getCompressionMethod() != null && !"JPEG".equals(params.getCompressionMethod())) {
-			throw new IllegalArgumentException("No compression method other than JPEG is supported for JPEG output!");
-		}
-		if (params.getJPEGForceBaseline()) {
-			param.setProgressiveMode(ImageWriteParam.MODE_DISABLED);
+		if (params != null) {
+			param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
+			param.setCompressionQuality(params.getJPEGQuality());
+			if (params.getCompressionMethod() != null && !"JPEG".equals(params.getCompressionMethod())) {
+				throw new IllegalArgumentException(
+						"No compression method other than JPEG is supported for JPEG output!");
+			}
+			if (params.getJPEGForceBaseline()) {
+				param.setProgressiveMode(ImageWriteParam.MODE_DISABLED);
+			}
 		}
 		return param;
 	}

echosvg-codec/src/main/java/io/sf/carte/echosvg/ext/awt/image/codec/imageio/ImageIOPNGImageWriter.java

@@ -30,6 +30,8 @@
 import javax.imageio.metadata.IIOMetadata;
 import javax.imageio.metadata.IIOMetadataNode;
 
+import io.sf.carte.echosvg.ext.awt.image.codec.impl.ColorUtil;
+
 /**
  * ImageWriter that encodes PNG images using Image I/O.
  *
@@ -47,7 +49,7 @@ public ImageIOPNGImageWriter() {
 
 	@Override
 	protected void updateColorMetadata(IIOMetadata meta, ColorSpace colorSpace) {
-		if (!colorSpace.isCS_sRGB() && colorSpace instanceof ICC_ColorSpace
+		if (!ColorUtil.isBuiltInColorSpace(colorSpace) && colorSpace instanceof ICC_ColorSpace
 				&& meta.isStandardMetadataFormatSupported()) {
 			final String metaName = "javax_imageio_png_1.0";
 			IIOMetadataNode root = (IIOMetadataNode) meta.getAsTree(metaName);

echosvg-codec/src/main/java/io/sf/carte/echosvg/ext/awt/image/codec/impl/ColorUtil.java

@@ -0,0 +1,49 @@
+/*
+
+   See the NOTICE file distributed with this work for additional
+   information regarding copyright ownership.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+ */
+package io.sf.carte.echosvg.ext.awt.image.codec.impl;
+
+import java.awt.color.ColorSpace;
+
+/**
+ * Color utilities.
+ *
+ * @version $Id$
+ */
+public class ColorUtil {
+
+	/**
+	 * Avoid instantiation.
+	 */
+	ColorUtil() {
+		super();
+	}
+
+	/**
+	 * 
+	 * @param colorSpace the color space.
+	 * @return {@code true} if it is a built-in color space.
+	 */
+	public static boolean isBuiltInColorSpace(ColorSpace colorSpace) {
+		return colorSpace.isCS_sRGB() || colorSpace == ColorSpace.getInstance(ColorSpace.CS_CIEXYZ)
+				|| colorSpace == ColorSpace.getInstance(ColorSpace.CS_GRAY)
+				|| colorSpace == ColorSpace.getInstance(ColorSpace.CS_LINEAR_RGB)
+				|| colorSpace == ColorSpace.getInstance(ColorSpace.CS_PYCC);
+	}
+
+}

echosvg-codec/src/main/java/io/sf/carte/echosvg/ext/awt/image/codec/impl/package-info.java

@@ -0,0 +1,22 @@
+/*
+
+   See the NOTICE file distributed with this work for additional
+   information regarding copyright ownership.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+ */
+/**
+ * Implementation classes, do not use outside of the codec module.
+ */
+package io.sf.carte.echosvg.ext.awt.image.codec.impl;

echosvg-codec/src/main/java/io/sf/carte/echosvg/ext/awt/image/codec/png/PNGImageEncoder.java

@@ -42,6 +42,7 @@
 import java.util.zip.Deflater;
 import java.util.zip.DeflaterOutputStream;
 
+import io.sf.carte.echosvg.ext.awt.image.codec.impl.ColorUtil;
 import io.sf.carte.echosvg.ext.awt.image.codec.util.ImageEncoderImpl;
 import io.sf.carte.echosvg.ext.awt.image.codec.util.PropertyUtil;
 
@@ -1093,7 +1094,7 @@ public void encode(RenderedImage im) throws IOException {
 
 	private void setICCProfileInfo(ColorModel colorModel) {
 		ColorSpace cs = colorModel.getColorSpace();
-		if (!cs.isCS_sRGB() && cs instanceof ICC_ColorSpace) {
+		if (!ColorUtil.isBuiltInColorSpace(cs) && cs instanceof ICC_ColorSpace) {
 			ICC_Profile profile = ((ICC_ColorSpace) cs).getProfile();
 			byte[] bdesc = profile.getData(ICC_Profile.icSigProfileDescriptionTag);
 			/*
@@ -1113,13 +1114,13 @@ private void setICCProfileInfo(ColorModel colorModel) {
 						String desc = new String(bdesc, offset, len, StandardCharsets.UTF_16BE).trim();
 						iccProfileName = desc;
 						iccProfileData = profile.getData();
+						return;
 					}
 				}
 			}
-		} else {
-			iccProfileName = null;
-			iccProfileData = null;
 		}
+		iccProfileName = null;
+		iccProfileData = null;
 	}
 
 	/**

echosvg-test/src/main/java/io/sf/carte/echosvg/test/TestUtil.java

@@ -90,7 +90,7 @@ public static String getProjectBuildURL(Class<?> cl, String projectDirname) {
 		String classUrl;
 		if (url == null) {
 			url = cwdURL();
-			File f =  new File(url.getFile(), projectDirname);
+			File f = new File(url.getFile(), projectDirname);
 			if (f.exists()) {
 				// CWD is root directory
 				try {

echosvg-test/src/main/java/io/sf/carte/echosvg/test/image/ImageComparator.java

@@ -34,6 +34,10 @@
  * comparisons with an arbitrary number of variants to match. See
  * {@link ImageVariants} for a description of the variants mechanism.
  * </p>
+ * <p>
+ * This software was written for image comparisons in the context of the EchoSVG
+ * project. Usage outside of that context is not supported.
+ * </p>
  */
 public class ImageComparator {
 
@@ -619,7 +623,7 @@ public static String getResultDescription(short code) {
 	 * @return an image comparing the two given images, one on each side.
 	 */
 	public static BufferedImage createCompareImage(BufferedImage ref, BufferedImage gen) {
-		BufferedImage cmp = new BufferedImage(ref.getWidth() * 2, ref.getHeight(), BufferedImage.TYPE_INT_ARGB);
+		BufferedImage cmp = createImageOfType(ref.getWidth() * 2, ref.getHeight(), ref);
 
 		Graphics2D g = cmp.createGraphics();
 		g.setPaint(Color.white);
@@ -650,7 +654,8 @@ public static BufferedImage createDiffImage(BufferedImage ref, BufferedImage gen
 		final int w = ref.getWidth();
 		final int h = ref.getHeight();
 
-		BufferedImage diff = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
+		BufferedImage diff = createImageOfType(w, h, ref);
+
 		WritableRaster refWR = ref.getRaster();
 		WritableRaster genWR = gen.getRaster();
 		WritableRaster dstWR = diff.getRaster();
@@ -701,6 +706,21 @@ public static BufferedImage createDiffImage(BufferedImage ref, BufferedImage gen
 		return diff;
 	}
 
+	private static BufferedImage createImageOfType(int width, int height, BufferedImage ref) {
+		BufferedImage image;
+
+		int type = ref.getType();
+		if (type != BufferedImage.TYPE_CUSTOM) {
+			image = new BufferedImage(width, height, type);
+		} else {
+			ColorModel cm = ref.getColorModel();
+			WritableRaster raster = cm.createCompatibleWritableRaster(width, height);
+			image = new BufferedImage(cm, raster, false, null);
+		}
+
+		return image;
+	}
+
 	/**
 	 * Creates a new image that is the exact difference between the two input
 	 * images.
@@ -722,7 +742,8 @@ public static BufferedImage createExactDiffImage(BufferedImage ref, BufferedImag
 					"Ref. image has height " + h + " but generated image is " + gen.getHeight());
 		}
 
-		BufferedImage diff = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
+		BufferedImage diff = createImageOfType(w, h, ref);
+
 		WritableRaster refWR = ref.getRaster();
 		WritableRaster genWR = gen.getRaster();
 		WritableRaster dstWR = diff.getRaster();
@@ -782,7 +803,8 @@ public static BufferedImage createMergedDiffImage(BufferedImage ref, BufferedIma
 		final int w = ref.getWidth();
 		final int h = ref.getHeight();
 
-		BufferedImage diff = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
+		BufferedImage diff = createImageOfType(w, h, ref);
+
 		WritableRaster refWR = ref.getRaster();
 		WritableRaster genWR = gen.getRaster();
 		WritableRaster rangeWR = rangeDiff.getRaster();