com.facebook.spectrum

Class Configuration

java.lang.Object

com.facebook.spectrum.Configuration

public class Configuration
extends java.lang.Object

The Configuration class defines configuration parameters that can be used to tweak low level options of how an operation is performed. Each of these configurations have a default value which can be overridden at two levels:

• At the Spectrum instance which can be created with a custom configuration object.
• At the operation which can provide a configuration override through its options.

See the external documentation for details on these options.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Configuration.Builder
static class	Configuration.ImageHint Optional hint when encoding WebP images
static class	Configuration.SamplingMethod Sampling algorithms for the exact resize block

Field Summary

Fields

Modifier and Type	Field and Description
ImageChromaSamplingMode	chromaSamplingModeOverride General: The ImageChromaSamplingMode to use when encoding.
ImageColor	defaultBackgroundColor General: Default background color to merge transparent images onto.
java.lang.Boolean	interpretMetadata General: Whether to read and interpret metadata such as EXIF for JPEG files.
java.lang.Boolean	propagateChromaSamplingModeFromSource General: Whether to propagate sampling mode from the source image.
Configuration.SamplingMethod	samplingMethod General: The sampling mode to use when scaling the image.
java.lang.Boolean	useCompatibleDcScanOpt Jpeg: Whether to use compatible DC scan configuration (keeping all DC components in the first scan) when encoding JPEG images.
java.lang.Boolean	useInterlacing Png: Whether to save PNG images with interlaced encoding.
java.lang.Boolean	useOptimizeScan Jpeg: Whether to use scan optimization when encoding JPEG images.
java.lang.Boolean	useProgressive Jpeg: Whether to save JPEG images in progressive scan encoding.
java.lang.Boolean	usePsnrQuantTable Jpeg: Whether to use an alternative quantization table optimized for PSNR when encoding JPEG images.
java.lang.Boolean	useTrellis Jpeg: Whether to use trellis optimization when encoding JPEG images.
Configuration.ImageHint	webpImageHint Webp: Provides an optional Configuration.ImageHint to the webp encoder
java.lang.Integer	webpMethod Webp: Compression quality/speed tradeoff where 0 is the fastest and 6 is the slowest/best compression.

Method Summary

Modifier and Type	Method and Description
static Configuration.Builder	Builder()
boolean	equals(java.lang.Object o)
int	hashCode()
static Configuration	makeEmpty()
static Configuration	makeForImageContainingGraphics()
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

defaultBackgroundColor

@Nullable
public final ImageColor defaultBackgroundColor

General: Default background color to merge transparent images onto.

interpretMetadata

@Nullable
public final java.lang.Boolean interpretMetadata

General: Whether to read and interpret metadata such as EXIF for JPEG files.

samplingMethod

@Nullable
public final Configuration.SamplingMethod samplingMethod

General: The sampling mode to use when scaling the image.

chromaSamplingModeOverride

@Nullable
public final ImageChromaSamplingMode chromaSamplingModeOverride

General: The ImageChromaSamplingMode to use when encoding.

propagateChromaSamplingModeFromSource

@Nullable
public final java.lang.Boolean propagateChromaSamplingModeFromSource

General: Whether to propagate sampling mode from the source image. If enabled, a source image with S444 will make the output default to S444.

useTrellis

@Nullable
public final java.lang.Boolean useTrellis

Jpeg: Whether to use trellis optimization when encoding JPEG images.

useProgressive

@Nullable
public final java.lang.Boolean useProgressive

Jpeg: Whether to save JPEG images in progressive scan encoding.

useOptimizeScan

@Nullable
public final java.lang.Boolean useOptimizeScan

Jpeg: Whether to use scan optimization when encoding JPEG images.

useCompatibleDcScanOpt

@Nullable
public final java.lang.Boolean useCompatibleDcScanOpt

Jpeg: Whether to use compatible DC scan configuration (keeping all DC components in the first scan) when encoding JPEG images.

usePsnrQuantTable

@Nullable
public final java.lang.Boolean usePsnrQuantTable

Jpeg: Whether to use an alternative quantization table optimized for PSNR when encoding JPEG images.

useInterlacing

@Nullable
public final java.lang.Boolean useInterlacing

Png: Whether to save PNG images with interlaced encoding.

webpMethod

@Nullable
public final java.lang.Integer webpMethod

Webp: Compression quality/speed tradeoff where 0 is the fastest and 6 is the slowest/best compression.

webpImageHint

@Nullable
public final Configuration.ImageHint webpImageHint

Webp: Provides an optional Configuration.ImageHint to the webp encoder

Method Detail

makeEmpty

public static Configuration makeEmpty()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

makeForImageContainingGraphics

public static Configuration makeForImageContainingGraphics()

Builder

public static Configuration.Builder Builder()

Returns:

A new builder to be used for creating Configuration objects.

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object