Allow to set image quality per media request (#33)

and add proper quality handling for web-optimized image delivery

changes.xml

@@ -28,6 +28,9 @@
         Add support for Web-Optimized Image Delivery (part of Next Generation Dynamic Media) - rendering asset renditions from AEM Sites instance on the edge.<br/>
         <b>This feature is active by default on AEMaaCS cloud instances, can be disabled via OSGi configuration</b>.
       ]]></action>
+      <action type="add" dev="sseifert" issue="33">
+        Allow to set image quality per media request.
+      </action>
       <action type="remove" dev="sseifert" issue="27">
         Remove deprecated functionality.
       </action>

src/main/java/io/wcm/handler/media/MediaArgs.java

@@ -68,6 +68,7 @@ public final class MediaArgs implements Cloneable {
   private Boolean includeAssetWebRenditions;
   private ImageSizes imageSizes;
   private PictureSource[] pictureSourceSets;
+  private Double imageQualityPercentage;
   private DragDropSupport dragDropSupport = DragDropSupport.AUTO;
   private IPERatioCustomize ipeRatioCustomize = IPERatioCustomize.AUTO;
   private boolean dynamicMediaDisabled;
@@ -672,6 +673,22 @@ public boolean isWebOptimizedImageDeliveryDisabled() {
     return this;
   }
 
+  /**
+   * @return Image quality in percent (0..1) for images with lossy compression (e.g. JPEG).
+   */
+  public @Nullable Double getImageQualityPercentage() {
+    return this.imageQualityPercentage;
+  }
+
+  /**
+   * @param value Image quality in percent (0..1) for images with lossy compression (e.g. JPEG).
+   * @return this
+   */
+  public @NotNull MediaArgs imageQualityPercentage(@Nullable Double value) {
+    this.imageQualityPercentage = value;
+    return this;
+  }
+
   /**
    * Drag&Drop support for media builder.
    * @return Drag&Drop support
@@ -809,6 +826,9 @@ public String toString() {
     if (pictureSourceSets != null && pictureSourceSets.length > 0) {
       sb.append("pictureSourceSets", "[" + StringUtils.join(pictureSourceSets, ",") + "]");
     }
+    if (imageQualityPercentage != null) {
+      sb.append("imageQualityPercentage ", imageQualityPercentage);
+    }
     if (dragDropSupport != DragDropSupport.AUTO) {
       sb.append("dragDropSupport ", dragDropSupport);
     }
@@ -856,6 +876,7 @@ public MediaArgs clone() { //NOPMD
     clone.includeAssetWebRenditions = this.includeAssetWebRenditions;
     clone.imageSizes = this.imageSizes;
     clone.pictureSourceSets = ArrayUtils.clone(this.pictureSourceSets);
+    clone.imageQualityPercentage = this.imageQualityPercentage;
     clone.dragDropSupport = this.dragDropSupport;
     clone.ipeRatioCustomize = this.ipeRatioCustomize;
     clone.dynamicMediaDisabled = this.dynamicMediaDisabled;

src/main/java/io/wcm/handler/media/MediaBuilder.java

@@ -231,6 +231,13 @@ public interface MediaBuilder {
   @NotNull
   MediaBuilder dummyImageUrl(@NotNull String value);
 
+  /**
+   * @param value Image quality in percent (0..1) for images with lossy compression (e.g. JPEG).
+   * @return this
+   */
+  @NotNull
+  MediaBuilder imageQualityPercentage(@NotNull Double value);
+
   /**
    * @param value Defines which types of AEM-generated renditions (with <code>cq5dam.</code> prefix) are taken into
    *          account when trying to resolve the media request.

src/main/java/io/wcm/handler/media/MediaFileType.java

@@ -22,6 +22,7 @@
 import java.util.EnumSet;
 import java.util.Set;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.apache.commons.lang3.StringUtils;
 import org.jetbrains.annotations.NotNull;
@@ -40,36 +41,40 @@ public enum MediaFileType {
   /**
    * JPEG
    */
-  JPEG(new String[] { ContentType.JPEG }, new String[] { FileExtension.JPEG, "jpeg" }),
+  JPEG(new String[] { ContentType.JPEG }, new String[] { FileExtension.JPEG, "jpeg" }, true),
 
   /**
    * PNG
    */
-  PNG(new String[] { ContentType.PNG }, new String[] { FileExtension.PNG }),
+  PNG(new String[] { ContentType.PNG }, new String[] { FileExtension.PNG }, false),
 
   /**
    * GIF
    */
-  GIF(new String[] { ContentType.GIF }, new String[] { FileExtension.GIF }),
+  GIF(new String[] { ContentType.GIF }, new String[] { FileExtension.GIF }, false),
 
   /**
    * TIFF
    */
-  TIFF(new String[] { ContentType.TIFF }, new String[] { FileExtension.TIFF, "tiff" }),
+  TIFF(new String[] { ContentType.TIFF }, new String[] { FileExtension.TIFF, "tiff" }, false),
 
   /**
    * SVG
    */
-  SVG(new String[] { ContentType.SVG }, new String[] { FileExtension.SVG });
+  SVG(new String[] { ContentType.SVG }, new String[] { FileExtension.SVG }, false);
 
 
   private final Set<String> contentTypes;
   private final Set<String> extensions;
+  private final boolean imageQualityPercentage;
 
   @SuppressWarnings("null")
-  MediaFileType(@NotNull String @NotNull [] contentTypes, @NotNull String @NotNull [] extensions) {
+  MediaFileType(@NotNull String @NotNull [] contentTypes,
+      @NotNull String @NotNull [] extensions,
+      boolean imageQualityPercentage) {
     this.contentTypes = Set.of(contentTypes);
     this.extensions = Set.of(extensions);
+    this.imageQualityPercentage = imageQualityPercentage;
   }
 
   /**
@@ -86,6 +91,13 @@ public Set<String> getExtensions() {
     return extensions;
   }
 
+  /**
+   * @return true if this image type has lossy compression and image quality is specified in percentage
+   */
+  public boolean isImageQualityPercentage() {
+    return imageQualityPercentage;
+  }
+
   /**
    * All file types that are supported by the Media Handler for rendering as image.
    */
@@ -200,4 +212,38 @@ private static Set<String> getFileExtensions(@NotNull EnumSet<MediaFileType> fil
         .collect(Collectors.toSet());
   }
 
+  /**
+   * Get Media file type by content type.
+   * @param contentType Content type
+   * @return Media file type or null if not found
+   */
+  @SuppressWarnings("null")
+  public static @Nullable MediaFileType getByContentType(@Nullable String contentType) {
+    if (contentType == null) {
+      return null;
+    }
+    String contentTypeLowerCase = StringUtils.toRootLowerCase(contentType);
+    return Stream.of(MediaFileType.values())
+        .filter(type -> type.getContentTypes().contains(contentTypeLowerCase))
+        .findFirst()
+        .orElse(null);
+  }
+
+  /**
+   * Get Media file type by file extension.
+   * @param extension File extension
+   * @return Media file type or null if not found
+   */
+  @SuppressWarnings("null")
+  public static @Nullable MediaFileType getByFileExtensions(@Nullable String extension) {
+    if (extension == null) {
+      return null;
+    }
+    String extensionLowerCase = StringUtils.toRootLowerCase(extension);
+    return Stream.of(MediaFileType.values())
+        .filter(type -> type.getExtensions().contains(extensionLowerCase))
+        .findFirst()
+        .orElse(null);
+  }
+
 }

src/main/java/io/wcm/handler/media/impl/AbstractMediaFileServlet.java

@@ -33,6 +33,7 @@
 import org.apache.sling.api.resource.Resource;
 import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import io.wcm.sling.commons.request.RequestPath;
@@ -89,7 +90,7 @@ protected void doGet(@NotNull SlingHttpServletRequest request, @NotNull SlingHtt
    * @param request Request
    * @return Resource pointing to nt:file or nt:resource node
    */
-  protected Resource getBinaryDataResource(SlingHttpServletRequest request) {
+  protected @Nullable Resource getBinaryDataResource(SlingHttpServletRequest request) {
     return request.getResource();
   }
 
@@ -100,8 +101,8 @@ protected Resource getBinaryDataResource(SlingHttpServletRequest request) {
    * @param response Response
    * @return true if the resource is not modified and should not be delivered anew
    */
-  protected boolean isNotModified(Resource resource, SlingHttpServletRequest request,
-      SlingHttpServletResponse response) {
+  protected boolean isNotModified(@NotNull Resource resource, @NotNull SlingHttpServletRequest request,
+      @NotNull SlingHttpServletResponse response) {
     // check resource's modification date against the If-Modified-Since header and send 304 if resource wasn't modified
     // never send expires header on author or publish instance (performance optimization - if medialib items changes
     // users have to refresh browsers cache)
@@ -113,7 +114,8 @@ protected boolean isNotModified(Resource resource, SlingHttpServletRequest reque
    * @param resource Resource
    * @return Binary data or null if not binary data found
    */
-  protected byte[] getBinaryData(Resource resource, @SuppressWarnings("unused") SlingHttpServletRequest request) throws IOException {
+  protected byte @Nullable [] getBinaryData(@NotNull Resource resource,
+      @SuppressWarnings({ "unused", "java:S1172" }) @NotNull SlingHttpServletRequest request) throws IOException {
     InputStream is = resource.adaptTo(InputStream.class);
     if (is == null) {
       return null;
@@ -131,7 +133,8 @@ protected byte[] getBinaryData(Resource resource, @SuppressWarnings("unused") Sl
    * @param resource Resource
    * @return Content type (never null)
    */
-  protected String getContentType(Resource resource, @SuppressWarnings("unused") SlingHttpServletRequest request) {
+  protected @NotNull String getContentType(@NotNull Resource resource,
+      @SuppressWarnings({ "unused", "java:S1172" }) @NotNull SlingHttpServletRequest request) {
     String mimeType = JcrBinary.getMimeType(resource);
     if (StringUtils.isEmpty(mimeType)) {
       mimeType = ContentType.OCTET_STREAM;
@@ -146,8 +149,8 @@ protected String getContentType(Resource resource, @SuppressWarnings("unused") S
    * @param request Request
    * @param response Response
    */
-  protected void sendBinaryData(byte[] binaryData, String contentType,
-      SlingHttpServletRequest request, SlingHttpServletResponse response) throws IOException {
+  protected void sendBinaryData(byte @NotNull [] binaryData, @NotNull String contentType,
+      @NotNull SlingHttpServletRequest request, @NotNull SlingHttpServletResponse response) throws IOException {
 
     // set content type and length
     response.setContentType(contentType);
@@ -174,7 +177,7 @@ else if (StringUtils.equals(contentType, ContentType.SVG)) {
     out.flush();
   }
 
-  private void setContentDispositionAttachmentHeader(SlingHttpServletRequest request, SlingHttpServletResponse response) {
+  private void setContentDispositionAttachmentHeader(@NotNull SlingHttpServletRequest request, @NotNull SlingHttpServletResponse response) {
     // Construct disposition header
     StringBuilder dispositionHeader = new StringBuilder("attachment;");
     String suffix = request.getRequestPathInfo().getSuffix();

src/main/java/io/wcm/handler/media/impl/ImageFileServlet.java

@@ -19,15 +19,12 @@
  */
 package io.wcm.handler.media.impl;
 
-import static io.wcm.handler.media.impl.ImageTransformation.isValidRotation;
-
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 
 import javax.servlet.Servlet;
 
 import org.apache.commons.lang3.StringUtils;
-import org.apache.commons.lang3.math.NumberUtils;
 import org.apache.sling.api.SlingHttpServletRequest;
 import org.apache.sling.api.resource.Resource;
 import org.apache.sling.api.servlets.HttpConstants;
@@ -70,46 +67,23 @@ public final class ImageFileServlet extends AbstractMediaFileServlet {
   private AssetStore assetStore;
 
   @Override
-  protected byte[] getBinaryData(Resource resource, SlingHttpServletRequest request) throws IOException {
+  protected byte @Nullable [] getBinaryData(@NotNull Resource resource, @NotNull SlingHttpServletRequest request) throws IOException {
     // get media app config
     MediaHandlerConfig config = AdaptTo.notNull(request, MediaHandlerConfig.class);
 
-    // check for image scaling parameters
-    int width = 0;
-    int height = 0;
-    String[] selectors = request.getRequestPathInfo().getSelectors();
-    if (selectors.length >= 3) {
-      width = NumberUtils.toInt(selectors[1]);
-      height = NumberUtils.toInt(selectors[2]);
-    }
+    // parse selectors
+    ImageFileServletSelector params = new ImageFileServletSelector(request.getRequestPathInfo().getSelectors());
+    int width = params.getWidth();
+    int height = params.getHeight();
+    CropDimension cropDimension = params.getCropDimension();
+    int rotation = params.getRotation();
+    int quality = params.getQuality();
+
+    // ensure valid image size
     if (width < 0 || height < 0 || (width == 0 && height == 0)) {
       return null;
     }
 
-    // check for cropping parameter
-    CropDimension cropDimension = null;
-    if (selectors.length >= 4) {
-      String cropString = selectors[3];
-      if (!StringUtils.equals(cropString, "-")) {
-        try {
-          cropDimension = CropDimension.fromCropString(cropString);
-        }
-        catch (IllegalArgumentException ex) {
-          // ignore
-        }
-      }
-    }
-
-    // check for rotation parameter
-    int rotation = 0;
-    if (selectors.length >= 5) {
-      String rotationString = selectors[4];
-      rotation = NumberUtils.toInt(rotationString);
-      if (!isValidRotation(rotation)) {
-        rotation = 0;
-      }
-    }
-
     Layer layer = ResourceLayerUtil.toLayer(resource, assetStore);
     if (layer == null) {
       return null;
@@ -153,16 +127,25 @@ else if (height == 0) {
       layer.resize(width, height);
     }
 
+    // determine layer quality with fallback to default image quality if not set
+    String contentType = getContentType(resource, request);
+    double layerQuality;
+    if (quality > 0) {
+      layerQuality = quality / 100d;
+    }
+    else {
+      layerQuality = config.getDefaultImageQuality(contentType);
+    }
+
     // stream to byte array
     ByteArrayOutputStream bos = new ByteArrayOutputStream();
-    String contentType = getContentType(resource, request);
-    layer.write(contentType, config.getDefaultImageQuality(contentType), bos);
+    layer.write(contentType, layerQuality, bos);
     bos.flush();
     return bos.toByteArray();
   }
 
   @Override
-  protected String getContentType(Resource resource, SlingHttpServletRequest request) {
+  protected @NotNull String getContentType(@NotNull Resource resource, @NotNull SlingHttpServletRequest request) {
 
     // get filename from suffix to get extension
     String fileName = request.getRequestPathInfo().getSuffix();
@@ -213,37 +196,4 @@ public static String getImageFileName(@NotNull String originalFilename,
     return namePart + "." + extensionPart;
   }
 
-  /**
-   * Build selector string for this servlet.
-   * @param width Width
-   * @param height Height
-   * @param cropDimension Crop dimension
-   * @param rotation Rotation
-   * @param contentDispositionAttachment Content disposition attachment
-   * @return Selector string
-   */
-  public static @NotNull String buildSelectorString(long width, long height,
-      @Nullable CropDimension cropDimension, @Nullable Integer rotation,
-      boolean contentDispositionAttachment) {
-    StringBuilder result = new StringBuilder()
-        .append(SELECTOR)
-        .append(".").append(Long.toString(width))
-        .append(".").append(Long.toString(height));
-
-    if (cropDimension != null) {
-      result.append(".").append(cropDimension.getCropString());
-    }
-    else if (rotation != null) {
-      result.append(".-");
-    }
-    if (rotation != null) {
-      result.append(".").append(rotation.toString());
-    }
-    if (contentDispositionAttachment) {
-      result.append(".").append(AbstractMediaFileServlet.SELECTOR_DOWNLOAD);
-    }
-
-    return result.toString();
-  }
-
 }