Table of Contents

toFile

Write output image data to a file.

If an explicit output format is not selected, it will be inferred from the extension, with JPEG, PNG, WebP, TIFF, DZI, and libvips' V format supported. Note that raw pixel data is only supported for buffer output.

A Promises/A+ promise is returned when callback is not provided.

Parameters

  • fileOut String the path to write the image data to.
  • callback Function? called on completion with two arguments (err, info). info contains the output image format, size (bytes), width, height and channels.

  • Throws Error Invalid parameters

Returns Promise<Object> when no callback is provided

toBuffer

Write output to a Buffer. JPEG, PNG, WebP, and RAW output are supported. By default, the format will match the input image, except GIF and SVG input which become PNG output.

callback, if present, gets three arguments (err, buffer, info) where:

  • err is an error message, if any.
  • buffer is the output image data.
  • info contains the output image format, size (bytes), width, height and channels. A Promises/A+ promise is returned when callback is not provided.

Parameters

Returns Promise<Buffer> when no callback is provided

withMetadata

Include all metadata (EXIF, XMP, IPTC) from the input image in the output image. The default behaviour, when withMetadata is not used, is to strip all metadata and convert to the device-independent sRGB colour space. This will also convert to and add a web-friendly sRGB ICC profile.

Parameters

  • withMetadata Object?

    • withMetadata.orientation Number? value between 1 and 8, used to update the EXIF Orientation tag.
  • Throws Error Invalid parameters

Returns Sharp

jpeg

Use these JPEG options for output image.

Parameters

  • options Object? output options

    • options.quality Number? quality, integer 1-100 (optional, default 80)
    • options.progressive Boolean? use progressive (interlace) scan (optional, default false)
    • options.chromaSubsampling String? set to '4:4:4' to prevent chroma subsampling when quality <= 90 (optional, default '4:2:0')
    • options.trellisQuantisation Boolean? apply trellis quantisation, requires mozjpeg (optional, default false)
    • options.overshootDeringing Boolean? apply overshoot deringing, requires mozjpeg (optional, default false)
    • options.optimiseScans Boolean? optimise progressive scans, forces progressive, requires mozjpeg (optional, default false)
    • options.optimizeScans Boolean? alternative spelling of optimiseScans (optional, default false)
    • options.force Boolean? force JPEG output, otherwise attempt to use input format (optional, default true)
  • Throws Error Invalid options

Returns Sharp

png

Use these PNG options for output image.

Parameters

  • options Object?

    • options.progressive Boolean? use progressive (interlace) scan (optional, default false)
    • options.compressionLevel Number? zlib compression level (optional, default 6)
    • options.adaptiveFiltering Boolean? use adaptive row filtering (optional, default true)
    • options.force Boolean? force PNG output, otherwise attempt to use input format (optional, default true)
  • Throws Error Invalid options

Returns Sharp

webp

Use these WebP options for output image.

Parameters

  • options Object? output options

    • options.quality Number? quality, integer 1-100 (optional, default 80)
    • options.alphaQuality Number? quality of alpha layer, integer 0-100 (optional, default 100)
    • options.lossless Boolean? use lossless compression mode (optional, default false)
    • options.nearLossless Boolean? use near_lossless compression mode (optional, default false)
    • options.force Boolean? force WebP output, otherwise attempt to use input format (optional, default true)
  • Throws Error Invalid options

Returns Sharp

tiff

Use these TIFF options for output image.

Parameters

  • options Object? output options

    • options.quality Number? quality, integer 1-100 (optional, default 80)
    • options.force Boolean? force TIFF output, otherwise attempt to use input format (optional, default true)
  • Throws Error Invalid options

Returns Sharp

raw

Force output to be raw, uncompressed uint8 pixel data.

Returns Sharp

toFormat

Force output to a given format.

Parameters

  • format (String | Object) as a String or an Object with an 'id' attribute
  • options Object output options

  • Throws Error unsupported format or options

Returns Sharp

tile

Use tile-based deep zoom (image pyramid) output. Set the format and options for tile images via the toFormat, jpeg, png or webp functions. Use a .zip or .szi file extension with toFile to write to a compressed archive file format.

Parameters

  • tile Object?
    • tile.size Number? tile size in pixels, a value between 1 and 8192. (optional, default 256)
    • tile.overlap Number? tile overlap in pixels, a value between 0 and 8192. (optional, default 0)
    • tile.container String? tile container, with value fs (filesystem) or zip (compressed file). (optional, default 'fs')
    • tile.layout String? filesystem layout, possible values are dz, zoomify or google. (optional, default 'dz')

Examples

sharp('input.tiff')
  .png()
  .tile({
    size: 512
  })
  .toFile('output.dz', function(err, info) {
    // output.dzi is the Deep Zoom XML definition
    // output_files contains 512x512 tiles grouped by zoom level
  });
  • Throws Error Invalid parameters

Returns Sharp