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Interface: ImageData

Defined in: storage/image.ts:25

Loaded image data providing one or more OpenSeadragon-compatible tile sources

Image data is either multi-channel, in which case it provides one tile source per channel, addressed by channel index; or it is not, in which case it provides a single tile source that is not addressed by channel. ImageData.getSizeC returns undefined for image data that is not multi-channel.

Multi-channel image data that implements RasterData.getTileData provides a single sample ("grayscale value") per pixel and channel, which the renderer contrast-stretches and colorizes (see ImageData.getChannelContrastLimits and ImageData.getChannelColor). Multi-channel image data that does not implement it is free to provide grayscale or RGB tile sources per channel, which are drawn as they are.

Extends​

Properties​

getChannelColor?​

optional getChannelColor?: (c) => Color | undefined

Defined in: storage/image.ts:66

Returns the color of a specific channel, or undefined if not available

Channels without a color (neither configured on the image nor returned here) are colorized with a default color derived from the channel index (see ImageUtils.getDefaultChannelColor), so that multi-channel image data without any color information renders as distinguishable channels rather than as a single white blob. This fallback is data-agnostic: if colors are available for only some channels, data providers should return suitable default colors for the remaining ones themselves, so that all channels of an image are colored consistently and the index-based fallback does not mix with colors from image metadata.

Parameters​

c​

number

The channel index (0-based)

Returns​

Color | undefined

The channel's color, or undefined if not available

getChannelContrastLimits?​

optional getChannelContrastLimits?: (c) => [number, number] | undefined

Defined in: storage/image.ts:84

Returns the contrast limits of a specific channel, or undefined if not available

The renderer scales each channel value linearly between the contrast limits, clamps the result to [0, 1] and multiplies it with the channel's color. Channels without contrast limits (neither configured on the image nor returned here) are stretched over the value range that the data type of their channel data can hold, as returned by ImageUtils.getDataTypeRange (the full integer range for integer typed arrays, [0, 1] for floating-point typed arrays, [0, 255] for plain arrays).

Parameters​

c​

number

The channel index (0-based)

Returns​

[number, number] | undefined

The channel's contrast limits, in the channel's value range, or undefined if not available

getChannelName?​

optional getChannelName?: (c) => string | undefined

Defined in: storage/image.ts:42

Returns the name of a specific channel, or undefined if not available

Parameters​

c​

number

Returns​

string | undefined

getChannelOpacity?​

optional getChannelOpacity?: (c) => number | undefined

Defined in: storage/image.ts:48

Returns the opacity of a specific channel, or undefined if not available

Parameters​

c​

number

Returns​

number | undefined

getChannelVisibility?​

optional getChannelVisibility?: (c) => boolean | undefined

Defined in: storage/image.ts:45

Returns the visibility of a specific channel, or undefined if not available

Parameters​

c​

number

Returns​

boolean | undefined

getTileData?​

optional getTileData?: (event) => Promise<{ height: number; values: NumericArray; width: number; }>

Defined in: storage/base.ts:101

Extracts the raw values of an invalidated tile

Provided by raster data whose tiles carry values rather than colors (e.g. label IDs, or one sample per pixel of an image channel), which the renderer recolors through a data transfer; raster data whose tiles are drawn as they are does not provide it. The tile in event already belongs to one of this raster's tile sources, which identifies the channel for multi-channel data.

The raster does not need to be cropped to the tile's source bounds: it may cover the full tile size, as the renderer crops it when drawing.

Parameters​

event​

TileInvalidatedEvent

The tile invalidation event

Returns​

Promise<{ height: number; values: NumericArray; width: number; }>

The values of the invalidated tile, one per raster pixel in row-major order, along with the width and height of the raster in pixels

Throws​

Error if the event does not contain raster data

Inherited from​

RasterData.getTileData

Methods​

close()​

close(): void

Defined in: storage/base.ts:18

Releases all resources held by this data object

Returns​

void

Inherited from​

RasterData.close

getSizeC()​

getSizeC(): number | undefined

Defined in: storage/image.ts:27

Returns the number of channels in the image, or undefined if not multi-channel

Returns​

number | undefined

getTileSource()​

getTileSource(c?): string | object | CustomTileSource

Defined in: storage/image.ts:39

Returns the tile source of a channel, or the only tile source of image data that is not multi-channel

Parameters​

c?​

number

The channel index (0-based), required for multi-channel image data and to be omitted otherwise

Returns​

string | object | CustomTileSource

The tile source, which can be a URL string, a TileSourceConfig object, or a CustomTileSource object

Throws​

Error if c is omitted for multi-channel image data, if c is passed for image data that is not multi-channel, or if c is out of bounds

Overrides​

RasterData.getTileSource