Class Canvas

constructor

• new Canvas(width, height, type?): Canvas

• Parameters

  • width: number

  • height: number

  • Optional type: "image" | "svg" | "pdf"

  Returns Canvas

Readonly PNG_ALL_FILTERS

Readonly PNG_FILTER_AVG

Readonly PNG_FILTER_NONE

Readonly PNG_FILTER_PAETH

Readonly PNG_FILTER_SUB

Readonly PNG_FILTER_UP

Readonly PNG_NO_FILTERS

height

Readonly stride

Readonly type

width

createJPEGStream

• createJPEGStream(config?): JPEGStream

• Parameters

  • Optional config: JpegConfig

  Returns JPEGStream

createPDFStream

• createPDFStream(config?): PDFStream

• Parameters

  • Optional config: PdfConfig

  Returns PDFStream

createPNGStream

• createPNGStream(config?): PNGStream

• Parameters

  • Optional config: PngConfig

  Returns PNGStream

getContext

• getContext(contextId, contextAttributes?): CanvasRenderingContext2D

• Parameters

  • contextId: "2d"

  • Optional contextAttributes: NodeCanvasRenderingContext2DSettings

  Returns CanvasRenderingContext2D

toBuffer

• toBuffer(cb): void

• For image canvases, encodes the canvas as a PNG. For PDF canvases, encodes the canvas as a PDF. For SVG canvases, encodes the canvas as an SVG.

  Parameters

  • cb: ((err, result) => void)

    • • (err, result): void

      • Parameters

        • err: null | Error

        • result: Buffer

        Returns void

  Returns void
• toBuffer(cb, mimeType, config?): void

• Parameters

  • cb: ((err, result) => void)

    • • (err, result): void

      • Parameters

        • err: null | Error

        • result: Buffer

        Returns void

  • mimeType: "image/png"

  • Optional config: PngConfig

  Returns void

• toBuffer(cb, mimeType, config?): void

• Parameters

  • cb: ((err, result) => void)

    • • (err, result): void

      • Parameters

        • err: null | Error

        • result: Buffer

        Returns void

  • mimeType: "image/jpeg"

  • Optional config: JpegConfig

  Returns void

• toBuffer(): Buffer

• For image canvases, encodes the canvas as a PNG. For PDF canvases, encodes the canvas as a PDF. For SVG canvases, encodes the canvas as an SVG.

  Returns Buffer
• toBuffer(mimeType, config?): Buffer

• Parameters

  • mimeType: "image/png"

  • Optional config: PngConfig

  Returns Buffer

• toBuffer(mimeType, config?): Buffer

• Parameters

  • mimeType: "image/jpeg"

  • Optional config: JpegConfig

  Returns Buffer

• toBuffer(mimeType, config?): Buffer

• Parameters

  • mimeType: "application/pdf"

  • Optional config: PdfConfig

  Returns Buffer

• toBuffer(mimeType): Buffer

• Returns the unencoded pixel data, top-to-bottom. On little-endian (most) systems, the array will be ordered BGRA; on big-endian systems, it will be ARGB.

  Parameters

  • mimeType: "raw"

  Returns Buffer

toDataURL

• toDataURL(): string

• Defaults to PNG image.

  Returns string
• toDataURL(mimeType): string

• Parameters

  • mimeType: "image/png"

  Returns string

• toDataURL(mimeType, quality?): string

• Parameters

  • mimeType: "image/jpeg"

  • Optional quality: number

  Returns string

• toDataURL(cb): void

• Non-standard. Defaults to PNG image.

  Parameters

  • cb: ((err, result) => void)

    • • (err, result): void

      • Parameters

        • err: null | Error

        • result: string

        Returns void

  Returns void
• toDataURL(mimeType, cb): void

• Non-standard.

  Parameters

  • mimeType: "image/png"

  • cb: ((err, result) => void)

    • • (err, result): void

      • Parameters

        • err: null | Error

        • result: string

        Returns void

  Returns void
• toDataURL(mimeType, cb): void

• Non-standard.

  Parameters

  • mimeType: "image/jpeg"

  • cb: ((err, result) => void)

    • • (err, result): void

      • Parameters

        • err: null | Error

        • result: string

        Returns void

  Returns void
• toDataURL(mimeType, config, cb): void

• Non-standard.

  Parameters

  • mimeType: "image/jpeg"

  • config: JpegConfig

  • cb: ((err, result) => void)

    • • (err, result): void

      • Parameters

        • err: null | Error

        • result: string

        Returns void

  Returns void
• toDataURL(mimeType, quality, cb): void

• Non-standard.

  Parameters

  • mimeType: "image/jpeg"

  • quality: number

  • cb: ((err, result) => void)

    • • (err, result): void

      • Parameters

        • err: null | Error

        • result: string

        Returns void

  Returns void