# ImagesServiceFactory
Date: 2012-02-24

## com.google.appengine.api.images
Class ImagesServiceFactory

    java.lang.Object
      com.google.appengine.api.images.ImagesServiceFactory

    public final class ImagesServiceFactory

extends java.lang.Object

Factory for creating an `ImagesService`, `Image`s and `Transform`s.

Method Summary
`static ImagesService` `getImagesService()` Creates an implementation of the ImagesService.
`static Composite` `makeComposite(Image image, int xOffset, int yOffset, float opacity, Composite.Anchor anchor)` Creates an image composition operation.
`static CompositeTransform` `makeCompositeTransform()` Creates a composite transform that can represent multiple transforms applied in series.
`static CompositeTransform` `makeCompositeTransform(java.util.Collection<Transform> transforms)` Creates a composite transform that can represent multiple transforms applied in series.
`static Transform` `makeCrop(double leftX, double topY, double rightX, double bottomY)` Creates a transform that will crop an image to fit within the bounding box specified.
`static Transform` `makeCrop(float leftX, float topY, float rightX, float bottomY)` Creates a transform that will crop an image to fit within the bounding box specified.
`static Transform` `makeHorizontalFlip()` Creates a transform that will horizontally flip an image.
`static Image` `makeImage(byte[] imageData)` Creates an image from the provided `imageData`.
`static Image` `makeImageFromBlob(BlobKey blobKey)` Create an image backed by the specified `blobKey`.
`static Transform` `makeImFeelingLucky()` Creates a transform that automatically adjust contrast and color levels.
`static Transform` `makeResize(int width, int height)` Creates a transform that will resize an image to fit within a box with width `width` and height `height`.
`static Transform` `makeResize(int width, int height, boolean allowStretch)` Creates a resize transform that will resize an image to fit within a box of width `width` and height `height`.
`static Transform` `makeResize(int width, int height, double cropOffsetX, double cropOffsetY)` Creates a transform that will resize an image to exactly fit a box with width `width` and height `height` by resizing to the less constraining dimension and cropping the other.
`static Transform` `makeResize(int width, int height, float cropOffsetX, float cropOffsetY)` Creates a transform that will resize an image to exactly fit a box with width `width` and height `height` by resizing to the less constraining dimension and cropping the other.
`static Transform` `makeRotate(int degrees)` Creates a transform that rotates an image by `degrees` degrees clockwise.
`static Transform` `makeVerticalFlip()` Creates a transform that will vertically flip an image.

Methods inherited from class java.lang.Object
`equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Method Detail

### getImagesService

    public static ImagesService getImagesService()

  Creates an implementation of the ImagesService.

  Returns:
    an images service

### makeImage

    public static Image makeImage(byte[] imageData)

  Creates an image from the provided `imageData`.

  Parameters:
    `imageData` - image data to store in the image
  Returns:
    an Image containing the supplied image data
  Throws:
    `java.lang.IllegalArgumentException` - If `imageData` is null or empty.

### makeImageFromBlob

    public static Image makeImageFromBlob(BlobKey blobKey)

  Create an image backed by the specified `blobKey`. Note that the returned `Image` object can be used with all `ImagesService` methods, but most of the methods on the Image itself will currently throw `UnsupportedOperationException`.

  Parameters:
    `blobKey` - referencing the image
  Returns:
    an Image that references the specified blob data

### makeResize

    public static Transform makeResize(int width,
                                       int height)

  Creates a transform that will resize an image to fit within a box with width `width` and height `height`.

  Parameters:
    `width` - width of the bounding box
    `height` - height of the bounding box
  Returns:
    a resize transform
  Throws:
    `java.lang.IllegalArgumentException` - If `width` or `height` are negative or greater than `MAX_RESIZE_DIMENSIONS` or if both `width` and `height` are 0.

### makeResize

    public static Transform makeResize(int width,
                                       int height,
                                       boolean allowStretch)

  Creates a resize transform that will resize an image to fit within a box of width `width` and height `height`. If `allowStretch` is `true`, the aspect ratio of the original image will be ignored.

  Parameters:
    `width` - width of the bounding box
    `height` - height of the bounding box
    `allowStretch` - allow the image to be resized ignoring the aspect ratio
  Returns:
    a resize transform
  Throws:
    `java.lang.IllegalArgumentException` - If `width` or `height` are negative or greater than `MAX_RESIZE_DIMENSIONS`, if both `width` and `height` are 0 or if is True and either `width` or `height` are 0.

### makeResize

    public static Transform makeResize(int width,
                                       int height,
                                       float cropOffsetX,
                                       float cropOffsetY)

  Creates a transform that will resize an image to exactly fit a box with width `width` and height `height` by resizing to the less constraining dimension and cropping the other. The center of the crop region is controlled by `cropOffsetX` and `cropOffsetY`.

  Parameters:
    `width` - width of the bounding box
    `height` - height of the bounding box
    `cropOffsetX` - the relative horizontal position of the center
    `cropOffsetY` - the relative vertical position of the center
  Returns:
    a resize transform
  Throws:
    `java.lang.IllegalArgumentException` - If `width` or `height` are negative or greater than `MAX_RESIZE_DIMENSIONS`, if either of `width` and `height` are 0 or if `cropOffsetX` or `cropOffsetY` are outside the range 0.0 to 1.0.

### makeResize

    public static Transform makeResize(int width,
                                       int height,
                                       double cropOffsetX,
                                       double cropOffsetY)

  Creates a transform that will resize an image to exactly fit a box with width `width` and height `height` by resizing to the less constraining dimension and cropping the other. The center of the crop region is controlled by `cropOffsetX` and `cropOffsetY`.

  Parameters:
    `width` - width of the bounding box
    `height` - height of the bounding box
    `cropOffsetX` - the relative horizontal position of the center
    `cropOffsetY` - the relative vertical position of the center
  Returns:
    a resize transform
  Throws:
    `java.lang.IllegalArgumentException` - If `width` or `height` are negative or greater than `MAX_RESIZE_DIMENSIONS`, if either of `width` and `height` are 0 or if `cropOffsetX` or `cropOffsetY` are outside the range 0.0 to 1.0.

### makeCrop

    public static Transform makeCrop(float leftX,
                                     float topY,
                                     float rightX,
                                     float bottomY)

  Creates a transform that will crop an image to fit within the bounding box specified. The arguments define the top left and bottom right corners of the bounding box used to crop the image as a percentage of the total image size. Each argument should be in the range 0.0 to 1.0 inclusive.

  Parameters:
    `leftX` - X coordinate of the top left corner of the bounding box
    `topY` - Y coordinate of the top left corner of the bounding box
    `rightX` - X coordinate of the bottom right corner of the bounding box
    `bottomY` - Y coordinate of the bottom right corner of the bounding box
  Returns:
    a crop transform
  Throws:
    `java.lang.IllegalArgumentException` - If any of the arguments are outside the range 0.0 to 1.0 or if `leftX >= rightX` or `topY >= bottomY`.

### makeCrop

    public static Transform makeCrop(double leftX,
                                     double topY,
                                     double rightX,
                                     double bottomY)

  Creates a transform that will crop an image to fit within the bounding box specified. The arguments define the top left and bottom right corners of the bounding box used to crop the image as a percentage of the total image size. Each argument should be in the range 0.0 to 1.0 inclusive.

  Parameters:
    `leftX` - X coordinate of the top left corner of the bounding box
    `topY` - Y coordinate of the top left corner of the bounding box
    `rightX` - X coordinate of the bottom right corner of the bounding box
    `bottomY` - Y coordinate of the bottom right corner of the bounding box
  Returns:
    a crop transform
  Throws:
    `java.lang.IllegalArgumentException` - If any of the arguments are outside the range 0.0 to 1.0 or if `leftX >= rightX` or `topY >= bottomY`.

### makeVerticalFlip

    public static Transform makeVerticalFlip()

  Creates a transform that will vertically flip an image.

  Returns:
    a vertical flip transform

### makeHorizontalFlip

    public static Transform makeHorizontalFlip()

  Creates a transform that will horizontally flip an image.

  Returns:
    a horizontal flip transform

### makeRotate

    public static Transform makeRotate(int degrees)

  Creates a transform that rotates an image by `degrees` degrees clockwise.

  Parameters:
    `degrees` - The number of degrees by which to rotate. Must be a multiple of 90.
  Returns:
    a rotation transform
  Throws:
    `java.lang.IllegalArgumentException` - If `degrees` is not divisible by 90

### makeImFeelingLucky

    public static Transform makeImFeelingLucky()

  Creates a transform that automatically adjust contrast and color levels. This is similar to the "I'm Feeling Lucky" button in Picasa.

  Returns:
    an ImFeelingLucky autolevel transform

### makeCompositeTransform

    public static CompositeTransform makeCompositeTransform(java.util.Collection<Transform> transforms)

  Creates a composite transform that can represent multiple transforms applied in series.

  Parameters:
    `transforms` - Transforms for this composite transform to apply.
  Returns:
    a composite transform containing the provided transforms

### makeCompositeTransform

    public static CompositeTransform makeCompositeTransform()

  Creates a composite transform that can represent multiple transforms applied in series.

  Returns:
    an empty composite transform

### makeComposite

    public static Composite makeComposite(Image image,
                                          int xOffset,
                                          int yOffset,
                                          float opacity,
                                          Composite.Anchor anchor)

  Creates an image composition operation.

  Parameters:
    `image` - The image to be composited.
    `xOffset` - Offset in the x axis from the anchor point.
    `yOffset` - Offset in the y axis from the anchor point.
    `opacity` - Opacity to be used for the image in range [0.0, 1.0].
    `anchor` - Anchor position from the enum `Composite.Anchor`. The anchor position of the image is aligned with the anchor position of the canvas and then the offsets are applied.
  Returns:
    A composition operation.
  Throws:
    `java.lang.IllegalArgumentException` - If `image` is null or empty, `xOffset` or `yOffset` is outside the range [-4000, 4000], `opacity` is outside the range [0.0, 1.0] or `anchor` is null.