# ImagesService
Date: 2012-02-24

## com.google.appengine.api.images
Interface ImagesService

    public interface ImagesService

The images service provides methods to apply transformations to images.

Nested Class Summary
`static class` `ImagesService.OutputEncoding` Valid output encoding formats usable for image transforms.

Field Summary
`static int` `MAX_COMPOSITES_PER_REQUEST`
`static int` `MAX_RESIZE_DIMENSIONS`
`static int` `MAX_TRANSFORMS_PER_REQUEST`
`static java.util.Set<java.lang.Integer>` `SERVING_CROP_SIZES` Deprecated.
`static java.util.Set<java.lang.Integer>` `SERVING_SIZES` Deprecated.
`static int` `SERVING_SIZES_LIMIT`

Method Summary
`Image` `applyTransform(Transform transform, Image image)` Applies the provided `transform` to the provided `image` encoding the transformed image stored using PNG file format.
`Image` `applyTransform(Transform transform, Image image, ImagesService.OutputEncoding encoding)` Applies the provided `transform` to the provided `image` encoding the transformed image stored using `encoding` file format.
`Image` `applyTransform(Transform transform, Image image, InputSettings inputSettings, OutputSettings ouputSettings)` Applies the provided `transform` to the provided `image` encoding the transformed image stored using `outputSettings` interpreting `image` according to `inputSettings`.
`Image` `applyTransform(Transform transform, Image image, OutputSettings settings)` Applies the provided `transform` to the provided `image` encoding the transformed image stored using `settings`.
`java.util.concurrent.Future<Image>` `applyTransformAsync(Transform transform, Image image)` Asynchronously applies the provided `transform` to the provided `image` encoding the transformed image stored using PNG file format.
`java.util.concurrent.Future<Image>` `applyTransformAsync(Transform transform, Image image, ImagesService.OutputEncoding encoding)` Asynchronously applies the provided `transform` to the provided `image` encoding the transformed image stored using `encoding` file format.
`java.util.concurrent.Future<Image>` `applyTransformAsync(Transform transform, Image image, InputSettings inputSettings, OutputSettings outputSettings)` Asynchronously applies the provided `transform` to the provided `image` encoding the transformed image stored using `settings` interpreting `image` according to `inputSettings`.
`java.util.concurrent.Future<Image>` `applyTransformAsync(Transform transform, Image image, OutputSettings settings)` Asynchronously applies the provided `transform` to the provided `image` encoding the transformed image stored using `settings`.
`Image` `composite(java.util.Collection<Composite> composites, int width, int height, long color)` Applies the provided `Collection` of `Composite`s using a canvas with dimensions determined by `width` and `height` and background color `color`.
`Image` `composite(java.util.Collection<Composite> composites, int width, int height, long color, ImagesService.OutputEncoding encoding)` Applies the provided `Collection` of `Composite`s using a canvas with dimensions determined by `width` and `height` and background color `color`.
`Image` `composite(java.util.Collection<Composite> composites, int width, int height, long color, OutputSettings settings)` Applies the provided `Collection` of `Composite`s using a canvas with dimensions determined by `width` and `height` and background color `color`.
`java.lang.String` `getServingUrl(BlobKey blobKey)` Obtains a URL that can serve the image stored as a blob dynamically.
`java.lang.String` `getServingUrl(BlobKey blobKey, int imageSize, boolean crop)` Calculates the serving URL for specific size and crop parameters from generic URL returned by `getServingUrl(BlobKey)`.
`int[][]` `histogram(Image image)` Calculates the histogram of the image.

Field Detail

### MAX_TRANSFORMS_PER_REQUEST

    static final int MAX_TRANSFORMS_PER_REQUEST

See Also:
  Constant Field Values

### MAX_RESIZE_DIMENSIONS

    static final int MAX_RESIZE_DIMENSIONS

See Also:
  Constant Field Values

### MAX_COMPOSITES_PER_REQUEST

    static final int MAX_COMPOSITES_PER_REQUEST

See Also:
  Constant Field Values

### SERVING_SIZES_LIMIT

    static final int SERVING_SIZES_LIMIT

See Also:
  Constant Field Values

### SERVING_SIZES

    @Deprecated
    static final java.util.Set<java.lang.Integer> SERVING_SIZES

  Deprecated.

### SERVING_CROP_SIZES

    @Deprecated
    static final java.util.Set<java.lang.Integer> SERVING_CROP_SIZES

  Deprecated.

Method Detail

### applyTransform

    Image applyTransform(Transform transform,
                         Image image)

  Applies the provided `transform` to the provided `image` encoding the transformed image stored using PNG file format. The transform is applied in place to the provided image.

  Parameters:
    `transform` - transform to be applied
    `image` - image to be transformed
  Returns:
    transformed image
  Throws:
    `java.lang.IllegalArgumentException` - If `transform` or `image` are invalid.
    `ImagesServiceFailureException` - If there is a problem with the Images Service

### applyTransformAsync

    java.util.concurrent.Future<Image> applyTransformAsync(Transform transform,
                                                           Image image)

  Asynchronously applies the provided `transform` to the provided `image` encoding the transformed image stored using PNG file format. The transform is applied in place to the provided image.

  Parameters:
    `transform` - transform to be applied
    `image` - image to be transformed
  Returns:
    A future containing the transformed image or one of the exceptions documented for `applyTransform(Transform, Image)`.

### applyTransform

    Image applyTransform(Transform transform,
                         Image image,
                         ImagesService.OutputEncoding encoding)

  Applies the provided `transform` to the provided `image` encoding the transformed image stored using `encoding` file format. The transform is applied in place to the provided image.

  Parameters:
    `transform` - transform to be applied
    `image` - image to be transformed
    `encoding` - output encoding to be used
  Returns:
    transformed image
  Throws:
    `java.lang.IllegalArgumentException` - If `transform`, `image` or `encoding` are invalid.
    `ImagesServiceFailureException` - If there is a problem with the Images Service

### applyTransformAsync

    java.util.concurrent.Future<Image> applyTransformAsync(Transform transform,
                                                           Image image,
                                                           ImagesService.OutputEncoding encoding)

  Asynchronously applies the provided `transform` to the provided `image` encoding the transformed image stored using `encoding` file format. The transform is applied in place to the provided image.

  Parameters:
    `transform` - transform to be applied
    `image` - image to be transformed
    `encoding` - output encoding to be used
  Returns:
    A future containing the transformed image or one of the exceptions documented for `applyTransform(Transform, Image, OutputEncoding)`.

### applyTransform

    Image applyTransform(Transform transform,
                         Image image,
                         OutputSettings settings)

  Applies the provided `transform` to the provided `image` encoding the transformed image stored using `settings`. The transform is applied in place to the provided image.

  Parameters:
    `transform` - transform to be applied
    `image` - image to be transformed
    `settings` - output settings to be used
  Returns:
    transformed image
  Throws:
    `java.lang.IllegalArgumentException` - If `transform`, `image` or `settings` are invalid.
    `ImagesServiceFailureException` - If there is a problem with the Images Service

### applyTransformAsync

    java.util.concurrent.Future<Image> applyTransformAsync(Transform transform,
                                                           Image image,
                                                           OutputSettings settings)

  Asynchronously applies the provided `transform` to the provided `image` encoding the transformed image stored using `settings`. The transform is applied in place to the provided image.

  Parameters:
    `transform` - transform to be applied
    `image` - image to be transformed
    `settings` - output settings to be used
  Returns:
    A future containing the transformed image or one of the exceptions documented for `applyTransform(Transform, Image, OutputSettings)`.

### applyTransform

    Image applyTransform(Transform transform,
                         Image image,
                         InputSettings inputSettings,
                         OutputSettings ouputSettings)

  Applies the provided `transform` to the provided `image` encoding the transformed image stored using `outputSettings` interpreting `image` according to `inputSettings`. The transform is applied in place to the provided image.

  Parameters:
    `transform` - transform to be applied
    `image` - image to be transformed
    `inputSettings` - input settings to be used
    `outputSettings` - output settings to be used
  Returns:
    transformed image
  Throws:
    `java.lang.IllegalArgumentException` - If `transform`, `image`, `inputSettings` or `outputSettings` are invalid.
    `ImagesServiceFailureException` - If there is a problem with the Images Service

### applyTransformAsync

    java.util.concurrent.Future<Image> applyTransformAsync(Transform transform,
                                                           Image image,
                                                           InputSettings inputSettings,
                                                           OutputSettings outputSettings)

  Asynchronously applies the provided `transform` to the provided `image` encoding the transformed image stored using `settings` interpreting `image` according to `inputSettings`. The transform is applied in place to the provided image.

  Parameters:
    `transform` - transform to be applied
    `image` - image to be transformed
    `inputSettings` - input settings to be used
    `outputSettings` - output settings to be used
  Returns:
    A future containing the transformed image or one of the exceptions documented for `applyTransform(Transform, Image, InputSettings, OutputSettings)`.

### composite

    Image composite(java.util.Collection<Composite> composites,
                    int width,
                    int height,
                    long color)

  Applies the provided `Collection` of `Composite`s using a canvas with dimensions determined by `width` and `height` and background color `color`. Uses PNG as its output encoding.

  Parameters:
    `composites` - Compositing operations to be applied.
    `width` - Width of the canvas in pixels.
    `height` - Height of the canvas in pixels.
    `color` - Background color of the canvas in ARGB format.
  Returns:
    A new image containing the result of composition.
  Throws:
    `java.lang.IllegalArgumentException` - If `width` or `height` is greater than 4000, color is outside the range [0, 0xffffffff], `composites` contains more than 16 elements or something is wrong with the contents of `composites`.
    `ImagesServiceFailureException` - If there is a problem with the Images Service

### composite

    Image composite(java.util.Collection<Composite> composites,
                    int width,
                    int height,
                    long color,
                    ImagesService.OutputEncoding encoding)

  Applies the provided `Collection` of `Composite`s using a canvas with dimensions determined by `width` and `height` and background color `color`.

  Parameters:
    `composites` - Compositing operations to be applied.
    `width` - Width of the canvas in pixels.
    `height` - Height of the canvas in pixels.
    `color` - Background color of the canvas in ARGB format.
    `encoding` - Encoding to be used for the resulting image.
  Returns:
    A new image containing the result of composition.
  Throws:
    `java.lang.IllegalArgumentException` - If `width` or `height` is greater than 4000, color is outside the range [0, 0xffffffff], `composites` contains more than 16 elements or something is wrong with the contents of `composites`.
    `ImagesServiceFailureException` - If there is a problem with the Images Service

### composite

    Image composite(java.util.Collection<Composite> composites,
                    int width,
                    int height,
                    long color,
                    OutputSettings settings)

  Applies the provided `Collection` of `Composite`s using a canvas with dimensions determined by `width` and `height` and background color `color`.

  Parameters:
    `composites` - Compositing operations to be applied.
    `width` - Width of the canvas in pixels.
    `height` - Height of the canvas in pixels.
    `color` - Background color of the canvas in ARGB format.
    `settings` - OutputSettings to be used for the resulting image.
  Returns:
    A new image containing the result of composition.
  Throws:
    `java.lang.IllegalArgumentException` - If `width` or `height` is greater than 4000, color is outside the range [0, 0xffffffff], `composites` contains more than 16 elements or something is wrong with the contents of `composites`.
    `ImagesServiceFailureException` - If there is a problem with the Images Service

### histogram

    int[][] histogram(Image image)

  Calculates the histogram of the image.

  Parameters:
    `image` - image for which to calculate a histogram
  Returns:
    An array of 3 arrays of length 256, each containing the image histogram for one color channel. The channels are ordered RGB from entry 0 to 3. Each channel ranges from 0 where the color is not present to 255 where the color is fully bright.

### getServingUrl

    java.lang.String getServingUrl(BlobKey blobKey)

  Obtains a URL that can serve the image stored as a blob dynamically.

  This URL is served by a high-performance dynamic image serving infrastructure that is available globally. The URL returned by this method is always public, but not guessable; private URLs are not currently supported. If you wish to stop serving the URL, delete the underlying blob key. This takes up to 24 hours to take effect. The URL format also allows dynamic resizing and crop with certain restrictions. To get dynamic resizing and cropping simply append options to the end of the url obtained via this call. Here is an example: `getServingUrl -> "http://lh3.ggpht.com/SomeCharactersGoesHere"`

  To get a 32 pixel sized version (aspect-ratio preserved) simply append "=s32" to the url: `"http://lh3.ggpht.com/SomeCharactersGoesHere=s32"`

  To get a 32 pixel cropped version simply append "=s32-c": `"http://lh3.ggpht.com/SomeCharactersGoesHere=s32-c"`

  Valid sizes are any integer in the range [0, 1600] and is available as SERVING_SIZES_LIMIT.

  Parameters:
    `blobKey` - blob key of the image to serve by the returned URL.
  Returns:
    a URL that can serve the image dynamically.
  Throws:
    `java.lang.IllegalArgumentException` - If blob key is not valid or doesn't contain an image.
    `ImagesServiceFailureException` - If there is a problem with the Images Service

### getServingUrl

    java.lang.String getServingUrl(BlobKey blobKey,
                                   int imageSize,
                                   boolean crop)

  Calculates the serving URL for specific size and crop parameters from generic URL returned by `getServingUrl(BlobKey)`.

  Parameters:
    `blobKey` - blob key of the image to serve by the returned URL with specified size and crop.
    `imageSize` - size of the served image in pixels.
    `crop` - controls whether the image should be resized or cropped.
  Returns:
    a URL that can serve the image dynamically.
  Throws:
    `java.lang.IllegalArgumentException` - If blob key is not valid or doesn't contain an image or specified size is not supported by the service.
    `ImagesServiceFailureException` - If there is a problem with the Images Service
  See Also:
    `getServingUrl(BlobKey)`