Package org.hippoecm.frontend.plugins.gallery.imageutil

Class ScaleImageOperation

java.lang.Object
org.hippoecm.frontend.plugins.gallery.imageutil.AbstractImageOperation
org.hippoecm.frontend.plugins.gallery.imageutil.AbstractScaleImageOperation
org.hippoecm.frontend.plugins.gallery.imageutil.ScaleImageOperation
All Implemented Interfaces:
ImageOperation
Direct Known Subclasses:
CropAndScaleImageOperation
public class ScaleImageOperation extends AbstractScaleImageOperation

Creates a scaled version of an image. The given scaling parameters define a bounding box with a certain width and height. Images that do not fit in this box (i.e. are too large) are always scaled down such that they do fit. If the aspect ratio of the original image differs from that of the bounding box, either the width or the height of scaled image will be less than that of the box.

Unless of course cropping is set to true, then the original images is cropped to fill the bounding box.

Smaller images are scaled up in the same way as large images are scaled down, but only if upscaling is true. When upscaling is false and the image is smaller than the bounding box, the scaled image will be equal to the original.

If the width or height of the scaling parameters is 0 or less, that side of the bounding box does not exist (i.e. is unbounded). If both sides of the bounding box are unbounded, the scaled image will be equal to the original.

  • Constructor Details

    • ScaleImageOperation

      public ScaleImageOperation(ScalingParameters parameters)
      Creates a scaling operation from a complete set of scaling parameters.
      Parameters:
      parameters - the parameters to use for the scaling

    • ScaleImageOperation

      @Deprecated public ScaleImageOperation(int width, int height, boolean upscaling)
      Deprecated.
      Use ScalingParameters.Builder instead.
      Creates a image scaling operation, defined by the bounding box of a certain width and height. The strategy will be set to ImageUtils.ScalingStrategy.QUALITY, and the maximum memory usage to zero (i.e. undefined).
      Parameters:
      width - the width of the bounding box in pixels
      height - the height of the bounding box in pixels
      upscaling - whether to enlarge images that are smaller than the bounding box

    • ScaleImageOperation

      @Deprecated public ScaleImageOperation(int width, int height, boolean upscaling, ImageUtils.ScalingStrategy strategy)
      Deprecated.
      Use ScalingParameters.Builder instead.
      Creates a image scaling operation, defined by the bounding box of a certain width and height.
      Parameters:
      width - the width of the bounding box in pixels
      height - the height of the bounding box in pixels
      upscaling - whether to enlarge images that are smaller than the bounding box
      strategy - the strategy to use for scaling the image (e.g. optimize for speed, quality, a trade-off between these two, etc.)

    • ScaleImageOperation

      @Deprecated public ScaleImageOperation(int width, int height, boolean upscaling, ImageUtils.ScalingStrategy strategy, float compressionQuality)
      Deprecated.
      Use ScalingParameters.Builder instead.
      Creates a image scaling operation, defined by the bounding box of a certain width and height.
      Parameters:
      width - the width of the bounding box in pixels
      height - the height of the bounding box in pixels
      upscaling - whether to enlarge images that are smaller than the bounding box
      strategy - the strategy to use for scaling the image (e.g. optimize for speed, quality, a trade-off between these two, etc.)
      compressionQuality - a float between 0 and 1 indicating the compression quality to use for writing the scaled image data.

    • ScaleImageOperation

      @Deprecated public ScaleImageOperation(int width, int height, boolean upscaling, boolean cropping, ImageUtils.ScalingStrategy strategy, float compressionQuality)
      Deprecated.
      Use ScalingParameters.Builder instead.
      Creates a image scaling operation, defined by the bounding box of a certain width and height.
      Parameters:
      width - the width of the bounding box in pixels
      height - the height of the bounding box in pixels
      upscaling - whether to enlarge images that are smaller than the bounding box
      cropping - whether to crop to original to fill the bounding box
      strategy - the strategy to use for scaling the image (e.g. optimize for speed, quality, a trade-off between these two, etc.)
      compressionQuality - a float between 0 and 1 indicating the compression quality to use for writing the scaled image data.

  • Method Details

    • run

      public ImageOperationResult run(InputStream data, String mimeType) throws GalleryException
      Description copied from interface: ImageOperation
      Runs an image operation and returns the result.
      Specified by:
      run in interface ImageOperation
      Overrides:
      run in class AbstractImageOperation
      Parameters:
      data - the image data. The stream is closed by this method.
      mimeType - MIME type of the image
      Throws:
      GalleryException - when the image operation fails

    • execute

      public void execute(InputStream data, ImageReader reader, ImageWriter writer) throws IOException
      Creates a scaled version of an image. The given scaling parameters define a bounding box with a certain width and height. Images that do not fit in this box (i.e. are too large) are always scaled down such that they do fit. If the aspect ratio of the original image differs from that of the bounding box, either the width or the height of scaled image will be less than that of the box.

      Smaller images are scaled up in the same way as large images are scaled down, but only if upscaling is true. When upscaling is false and the image is smaller than the bounding box, the scaled image will be equal to the original.

      If the width or height of the scaling parameters is 0 or less, that side of the bounding box does not exist (i.e. is unbounded). If both sides of the bounding box are unbounded, the scaled image will be equal to the original.

      Specified by:
      execute in class AbstractImageOperation
      Parameters:
      data - the original image data
      reader - reader for the image data
      writer - writer for the image data
      Throws:
      IOException - when the image operation fails

    • processImage

      protected BufferedImage processImage(ImageReader reader, int originalWidth, int originalHeight) throws IOException
      Throws:
      IOException