copper3d / Modules / Utils/segmentation/core/MaskVolume / MaskVolume

Class: MaskVolume ​

Utils/segmentation/core/MaskVolume.MaskVolume

Table of contents ​

Constructors ​

• constructor

Properties ​

• bytesPerSlice
• colorMap
• data
• dims
• numChannels
• version

Methods ​

• buildRgbToChannelMap
• clear
• clearSlice
• clone
• getBytesPerSlice
• getChannelColor
• getChannels
• getColorMap
• getDimensions
• getIndex
• getMemoryUsage
• getRawData
• getSliceDimensions
• getSliceImageData
• getSliceUint8
• getVersion
• getVoxel
• hasData
• renderBlended
• renderColoredMulti
• renderColoredSingle
• renderGrayscale
• renderLabelSliceInto
• resetChannelColors
• setChannelColor
• setRawData
• setSliceFromImageData
• setSliceLabelsFromImageData
• setSliceUint8
• setVoxel
• validateSliceIndex

Constructors ​

constructor ​

• new MaskVolume(width, height, depth, channels?, customColorMap?)

Create a new MaskVolume.

All voxels are initialised to 0.

Parameters ​

Throws

If any dimension or the channel count is < 1.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:90

Properties ​

bytesPerSlice ​

• Private Readonly bytesPerSlice: number

Number of bytes in one complete z-slice. Equal to width × height × channels.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:58

colorMap ​

• Private colorMap: ChannelColorMap

Per-channel color map used for colored rendering modes.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:61

data ​

• Private data: Uint8Array

Contiguous backing buffer — layout [z][y][x][channel].

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:46

dims ​

• Private Readonly dims: Dimensions

Volume size in voxels.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:49

numChannels ​

• Private Readonly numChannels: number

Number of value channels per voxel (≥ 1).

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:52

version ​

• Private version: number = 0

Monotonic data-mutation counter.

Incremented by every method that mutates voxel data (not color). Consumers (e.g. the contour cache in RenderingUtils) key cached derivations on this value so an edit automatically invalidates them — it is impossible to forget an invalidation point because every write bumps the version. Color-map changes do not bump it (colors are applied at fill time, never cached).

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:73

Methods ​

buildRgbToChannelMap ​

▸ Private buildRgbToChannelMap(): Map<number, number>

Build a Map from RGB packed integer to channel label for reverse lookup. Uses this instance's colorMap (channels 1-8, skips 0 = transparent).

Instance method ensures custom per-layer colors are correctly reverse-mapped.

Returns ​

Map<number, number>

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:619

clear ​

▸ clear(): void

Zero every voxel in the entire volume (all channels).

Returns ​

void

Example

vol.clear();
vol.getVoxel(256, 256, 50); // 0

vol.clear();
vol.getVoxel(256, 256, 50); // 0

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:860

clearSlice ​

▸ clearSlice(sliceIndex, axis?, channel?): void

Zero every voxel in a single slice along the given axis.

If channel is provided, only that channel is cleared; otherwise all channels in the slice are cleared.

Parameters ​

Returns ​

void

Throws

If sliceIndex is out of bounds.

Example

// Erase a single axial slice
vol.clearSlice(50, 'z');

// Erase only channel 1 of slice 50
vol.clearSlice(50, 'z', 1);

// Erase a single axial slice
vol.clearSlice(50, 'z');

// Erase only channel 1 of slice 50
vol.clearSlice(50, 'z', 1);

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:915

clone ​

▸ clone(): MaskVolume

Create an independent deep copy of this volume.

The clone has the same dimensions, channels, data, and color map but shares no references with the original.

Returns ​

MaskVolume

A new MaskVolume with identical content.

Example

// Undo support: snapshot before an operation
const snapshot = vol.clone();
performEdit(vol);
// Rollback: vol.setRawData(snapshot.getRawData());

// Undo support: snapshot before an operation
const snapshot = vol.clone();
performEdit(vol);
// Rollback: vol.setRawData(snapshot.getRawData());

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:834

getBytesPerSlice ​

▸ getBytesPerSlice(): number

Return the number of bytes in one complete z-slice.

Equal to width × height × channels. Useful for direct buffer index arithmetic in performance-critical code paths.

Returns ​

number

Bytes per z-slice.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:752

getChannelColor ​

▸ getChannelColor(channel): RGBAColor

Get the current color for a channel.

Falls back to the background color (transparent) if no color is defined.

Parameters ​

Returns ​

RGBAColor

A copy of the RGBA color.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:246

getChannels ​

▸ getChannels(): number

Return the number of channels per voxel.

Returns ​

number

Channel count (≥ 1).

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:740

getColorMap ​

▸ getColorMap(): ChannelColorMap

Get a shallow copy of the entire color map.

Returns ​

ChannelColorMap

A copy of the color map (safe to mutate).

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:274

getDimensions ​

▸ getDimensions(): Dimensions

Return a copy of the volume dimensions.

Returns ​

Dimensions

{ width, height, depth } — a fresh object (safe to mutate).

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:731

getIndex ​

▸ Private getIndex(x, y, z, channel?): number

Map 3D coordinates + channel to a flat 1D index.

Memory layout (slice-major):

index = (z × height × width × channels)
      + (y × width × channels)
      + (x × channels)
      + channel

index = (z × height × width × channels)
      + (y × width × channels)
      + (x × channels)
      + channel

Parameters ​

Returns ​

number

Flat 1D index into this.data.

Throws

If any coordinate or channel is out of bounds.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:150

getMemoryUsage ​

▸ getMemoryUsage(): number

Return total memory used by the backing buffer, in bytes.

Returns ​

number

width × height × depth × channels bytes.

Example

const vol = new MaskVolume(512, 512, 100);
vol.getMemoryUsage(); // 26_214_400 (~25 MB)

const vol = new MaskVolume(512, 512, 100);
vol.getMemoryUsage(); // 26_214_400 (~25 MB)

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:767

getRawData ​

▸ getRawData(): Uint8Array

Return a reference to the raw backing buffer.

Use this for direct read access (e.g. serialisation, GPU upload). Mutating the returned array mutates the volume.

Returns ​

Uint8Array

The underlying Uint8Array.

Example

// Serialise for network transfer
const bytes = vol.getRawData();
socket.send(bytes.buffer);

// Serialise for network transfer
const bytes = vol.getRawData();
socket.send(bytes.buffer);

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:788

getSliceDimensions ​

▸ Private getSliceDimensions(axis): [number, number]

Get the 2D slice dimensions for a given axis.

Parameters ​

Returns ​

[number, number]

[width, height] of the slice.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:1087

getSliceImageData ​

▸ getSliceImageData(sliceIndex, axis?, options?): ImageData

Extract a 2D slice as an ImageData with color mapping.

Slice dimensions depend on the axis:

Parameters ​

Returns ​

ImageData

ImageData ready for ctx.putImageData().

Throws

If sliceIndex is out of bounds for the given axis.

Example

// Grayscale (default, backward compatible)
const gs = vol.getSliceImageData(50, 'z');

// Colored single-channel
const cs = vol.getSliceImageData(50, 'z', {
  mode: RenderMode.COLORED_SINGLE,
  channel: 0,
});

// Multi-channel priority
const mc = vol.getSliceImageData(50, 'z', {
  mode: RenderMode.COLORED_MULTI,
  visibleChannels: [false, true, true, true],
});

// Grayscale (default, backward compatible)
const gs = vol.getSliceImageData(50, 'z');

// Colored single-channel
const cs = vol.getSliceImageData(50, 'z', {
  mode: RenderMode.COLORED_SINGLE,
  channel: 0,
});

// Multi-channel priority
const mc = vol.getSliceImageData(50, 'z', {
  mode: RenderMode.COLORED_MULTI,
  visibleChannels: [false, true, true, true],
});

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:322

getSliceUint8 ​

▸ getSliceUint8(sliceIndex, axis?): Object

Extract a 2D slice as a flat Uint8Array (one byte per voxel per channel).

For a 1-channel volume the result is sliceWidth × sliceHeight bytes, each byte being the label value at that pixel. This is suitable for sending to a backend that expects raw label data (e.g. NIfTI slice replacement).

Parameters ​

Returns ​

Object

A copy of the slice data plus its dimensions.

Throws

If sliceIndex is out of bounds.

Example

const { data, width, height } = vol.getSliceUint8(50, 'z');
// data.length === width * height * channels

const { data, width, height } = vol.getSliceUint8(50, 'z');
// data.length === width * height * channels

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:987

getVersion ​

▸ getVersion(): number

Return the current data-mutation version.

Increments on every voxel write. Use as a cache key so derived data (e.g. extracted contours) is invalidated whenever the volume changes.

Returns ​

number

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:212

getVoxel ​

▸ getVoxel(x, y, z, channel?): number

Read a single voxel value.

Parameters ​

Returns ​

number

The stored value (0 – 255).

Throws

If any coordinate is out of bounds.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:184

hasData ​

▸ hasData(): boolean

Check if the volume contains any non-zero voxel data.

Returns true if at least one voxel has a non-zero value, false if all voxels are zero (empty mask).

This is useful for determining if a layer has actual mask annotations before saving or exporting.

Returns ​

boolean

True if any voxel is non-zero, false if all zeros.

Example

const vol = new MaskVolume(512, 512, 100);
vol.hasData(); // false (all zeros)

vol.setVoxel(256, 256, 50, 255);
vol.hasData(); // true

const vol = new MaskVolume(512, 512, 100);
vol.hasData(); // false (all zeros)

vol.setVoxel(256, 256, 50, 255);
vol.hasData(); // true

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:885

renderBlended ​

▸ Private renderBlended(pixels, width, height, sliceIndex, axis, colorMap, visibleChannels, opacity): void

Render all visible channels with additive blending.

Each channel contributes its color weighted by intensity × opacity. RGB values are clamped to 255.

Parameters ​

Returns ​

void

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:1312

renderColoredMulti ​

▸ Private renderColoredMulti(pixels, width, height, sliceIndex, axis, colorMap, visibleChannels, opacity): void

Render all visible channels with distinct colors.

The highest-index non-zero visible channel wins (priority-based).

Parameters ​

Returns ​

void

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:1238

renderColoredSingle ​

▸ Private renderColoredSingle(pixels, width, height, sliceIndex, axis, channel, colorMap, opacity): void

Render a single channel with its predefined color.

Alpha is modulated by the voxel intensity and the opacity multiplier.

Parameters ​

Returns ​

void

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:1177

renderGrayscale ​

▸ Private renderGrayscale(pixels, width, height, sliceIndex, axis, channel): void

Render a single channel as grayscale (original behaviour).

Non-zero voxels are fully opaque (A = 255), zero voxels are transparent (A = 0).

Parameters ​

Returns ​

void

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:1124

renderLabelSliceInto ​

▸ renderLabelSliceInto(sliceIndex, axis?, target, channelVisible?, opacity?): void

Render a 1-channel label slice into a pre-allocated RGBA ImageData buffer.

Each voxel stores a label value (0-8). Label 0 = transparent. Labels 1-8 are mapped to colors via MASK_CHANNEL_COLORS, filtered by the channelVisible array.

Parameters ​

Returns ​

void

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:647

resetChannelColors ​

▸ resetChannelColors(channel?): void

Reset the color map for one or all labels to defaults.

Parameters ​

Returns ​

void

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:256

setChannelColor ​

▸ setChannelColor(channel, color): void

Update the color for a specific label/channel in the color map.

For label-based volumes (1-channel), the channel parameter refers to the label value (0-8), not the storage channel index.

Parameters ​

Returns ​

void

Throws

If channel is outside valid label range [0, 8].

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:229

setRawData ​

▸ setRawData(newData): void

Replace the entire backing buffer.

The provided array must have exactly the same length as the current buffer (width × height × depth × channels).

Parameters ​

Returns ​

void

Throws

If the length does not match.

Example

// Restore from a saved snapshot
const saved = new Uint8Array(savedBuffer);
vol.setRawData(saved);

// Restore from a saved snapshot
const saved = new Uint8Array(savedBuffer);
vol.setRawData(saved);

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:808

setSliceFromImageData ​

▸ setSliceFromImageData(sliceIndex, imageData, axis?, channel?): void

Write a 2D ImageData back into the volume for the given axis/slice.

When the volume has 4 channels, all RGBA components are stored (ch0=R, ch1=G, ch2=B, ch3=A) for lossless round-trip. Otherwise, the R channel of each pixel is used as grayscale.

Parameters ​

Returns ​

void

Throws

If sliceIndex is out of bounds.

Throws

If imageData dimensions don't match.

Example

const imgData = ctx.getImageData(0, 0, 512, 512);
vol.setSliceFromImageData(50, imgData, 'z');

const imgData = ctx.getImageData(0, 0, 512, 512);
vol.setSliceFromImageData(50, imgData, 'z');

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:386

setSliceLabelsFromImageData ​

▸ setSliceLabelsFromImageData(sliceIndex, imageData, axis?, activeChannel?, channelVisible?): void

/**

• Store label data from canvas RGBA ImageData into a 1-channel volume.
• For each pixel: matches the RGB color against MASK_CHANNEL_COLORS to
• determine which channel label to store. If no match is found, falls
• back to activeChannel. Transparent pixels (alpha === 0) are stored as 0.
• This is the write counterpart to renderLabelSliceInto.

Parameters ​

Returns ​

void

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:499

setSliceUint8 ​

▸ setSliceUint8(sliceIndex, data, axis?): void

Write a 2D slice from a flat Uint8Array back into the volume.

This is the inverse of getSliceUint8. The data array must have exactly sliceWidth × sliceHeight × channels bytes.

Parameters ​

Returns ​

void

Throws

If sliceIndex is out of bounds.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:1040

setVoxel ​

▸ setVoxel(x, y, z, value, channel?): void

Write a single voxel value.

Values are clamped to the Uint8 range [0, 255] by the typed array.

Parameters ​

Returns ​

void

Throws

If any coordinate is out of bounds.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:201

validateSliceIndex ​

▸ Private validateSliceIndex(sliceIndex, axis): void

Validate that a slice index is within bounds for the given axis.

Parameters ​

Returns ​

void

Throws

If out of bounds.

Defined in ​

src/Utils/segmentation/core/MaskVolume.ts:1103