transformers.js/pr_1649/en/api/utils/image.md

utils/image

Helper module for image processing.

These functions and classes are only used internally, meaning an end-user shouldn't need to access anything here.

• utils/image
  • static
    • .RawImage
      • new RawImage(data, width, height, channels)
      • instance
        • .size ⇒ Array
        • .grayscale() ⇒ RawImage
        • .rgb() ⇒ RawImage
        • .rgba() ⇒ RawImage
        • .putAlpha(mask) ⇒ RawImage
        • .resize(width, height, options) ⇒ Promise.<RawImage>
        • .split() ⇒ Array
        • .clone() ⇒ RawImage
        • .convert(numChannels) ⇒ RawImage
        • .save(path) ⇒ Promise.<void>
        • .toSharp() ⇒ Sharp
      • static
        • .read(input) ⇒ Promise.<RawImage>
        • .fromCanvas(canvas) ⇒ RawImage
        • .fromURL(url) ⇒ Promise.<RawImage>
        • .fromBlob(blob) ⇒ Promise.<RawImage>
        • .fromTensor(tensor)
    • .load_image
  • inner
    • ~CONTENT_TYPE_MAP

---

utils/image.RawImage

Kind: static class of utils/image

• .RawImage
  • new RawImage(data, width, height, channels)
  • instance
    • .size ⇒ Array
    • .grayscale() ⇒ RawImage
    • .rgb() ⇒ RawImage
    • .rgba() ⇒ RawImage
    • .putAlpha(mask) ⇒ RawImage
    • .resize(width, height, options) ⇒ Promise.<RawImage>
    • .split() ⇒ Array
    • .clone() ⇒ RawImage
    • .convert(numChannels) ⇒ RawImage
    • .save(path) ⇒ Promise.<void>
    • .toSharp() ⇒ Sharp
  • static
    • .read(input) ⇒ Promise.<RawImage>
    • .fromCanvas(canvas) ⇒ RawImage
    • .fromURL(url) ⇒ Promise.<RawImage>
    • .fromBlob(blob) ⇒ Promise.<RawImage>
    • .fromTensor(tensor)

---

new RawImage(data, width, height, channels)

Create a new RawImage object.

  ParamTypeDescription




dataUint8ClampedArray | Uint8ArrayThe pixel data.


widthnumberThe width of the image.


heightnumberThe height of the image.


channels1 | 2 | 3 | 4The number of channels.

  

---

rawImage.size ⇒ Array

Returns the size of the image (width, height).

Kind: instance property of RawImage
Returns: Array - The size of the image (width, height).

---

rawImage.grayscale() ⇒ RawImage

Convert the image to grayscale format.

Kind: instance method of RawImage
Returns: RawImage - this to support chaining.

---

rawImage.rgb() ⇒ RawImage

Convert the image to RGB format.

Kind: instance method of RawImage
Returns: RawImage - this to support chaining.

---

rawImage.rgba() ⇒ RawImage

Convert the image to RGBA format.

Kind: instance method of RawImage
Returns: RawImage - this to support chaining.

---

rawImage.putAlpha(mask) ⇒ RawImage

Apply an alpha mask to the image. Operates in place.

Kind: instance method of RawImage
Returns: RawImage - The masked image.
Throws:

• Error If the mask is not the same size as the image.

• Error If the image does not have 4 channels.

• Error If the mask is not a single channel.

  ParamTypeDescription
  

  maskRawImageThe mask to apply. It should have a single channel.

---

rawImage.resize(width, height, options) ⇒ Promise.<RawImage>

Resize the image to the given dimensions. This method uses the canvas API to perform the resizing.

Kind: instance method of RawImage
Returns: Promise.<RawImage> - this to support chaining.

  ParamTypeDescription




widthnumberThe width of the new image. null or -1 will preserve the aspect ratio.


heightnumberThe height of the new image. null or -1 will preserve the aspect ratio.


optionsObjectAdditional options for resizing.


[options.resample]0 | 1 | 2 | 3 | 4 | 5 | stringThe resampling method to use.

  

---

rawImage.split() ⇒ Array

Split this image into individual bands. This method returns an array of individual image bands from an image. For example, splitting an "RGB" image creates three new images each containing a copy of one of the original bands (red, green, blue).

Inspired by PIL's Image.split() function.

Kind: instance method of RawImage
Returns: Array - An array containing bands.

---

rawImage.clone() ⇒ RawImage

Clone the image

Kind: instance method of RawImage
Returns: RawImage - The cloned image

---

rawImage.convert(numChannels) ⇒ RawImage

Helper method for converting image to have a certain number of channels

Kind: instance method of RawImage
Returns: RawImage - this to support chaining.

  ParamTypeDescription




numChannelsnumberThe number of channels. Must be 1, 3, or 4.

  

---

rawImage.save(path) ⇒ Promise.<void>

Save the image to the given path.

Kind: instance method of RawImage

  ParamTypeDescription




pathstringThe path to save the image to.

  

---

rawImage.toSharp() ⇒ Sharp

Convert the image to a Sharp instance.

Kind: instance method of RawImage
Returns: Sharp - The Sharp instance.

---

RawImage.read(input) ⇒ Promise.<RawImage>

Helper method for reading an image from a variety of input types.

Kind: static method of RawImage
Returns: Promise.<RawImage> - The image object.

Example: Read image from a URL.

let image = await RawImage.read('https://huggingface.co/datasets/Xenova/transformers.js-docs/resolve/main/football-match.jpg');
// RawImage {
//   "data": Uint8ClampedArray [ 25, 25, 25, 19, 19, 19, ... ],
//   "width": 800,
//   "height": 533,
//   "channels": 3
// }

  ParamType




inputRawImage | string | URL | Blob | HTMLCanvasElement | OffscreenCanvas
  

---

RawImage.fromCanvas(canvas) ⇒ RawImage

Read an image from a canvas.

Kind: static method of RawImage
Returns: RawImage - The image object.

  ParamTypeDescription




canvasHTMLCanvasElement | OffscreenCanvasThe canvas to read the image from.

  

---

RawImage.fromURL(url) ⇒ Promise.<RawImage>

Read an image from a URL or file path.

Kind: static method of RawImage
Returns: Promise.<RawImage> - The image object.

  ParamTypeDescription




urlstring | URLThe URL or file path to read the image from.

  

---

RawImage.fromBlob(blob) ⇒ Promise.<RawImage>

Helper method to create a new Image from a blob.

Kind: static method of RawImage
Returns: Promise.<RawImage> - The image object.

  ParamTypeDescription




blobBlobThe blob to read the image from.

  

---

RawImage.fromTensor(tensor)

Helper method to create a new Image from a tensor

Kind: static method of RawImage

  ParamType




tensorTensor
  

---

utils/image.load_image

Helper function to load an image from a URL, path, etc.

Kind: static constant of utils/image

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utils/image~CONTENT_TYPE_MAP

Mapping from file extensions to MIME types.

Kind: inner constant of utils/image

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