transformers.js/pr_1452/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 ⇒ *
        • .grayscale() ⇒ RawImage
        • .rgb() ⇒ RawImage
        • .rgba() ⇒ RawImage
        • .putAlpha(mask) ⇒ RawImage
        • .resize(width, height, options) ⇒ Promise.<RawImage>
        • .split() ⇒ Array.<RawImage>
        • .clone() ⇒ RawImage
        • .convert(numChannels) ⇒ RawImage
        • .save(path)
      • static
        • .read(input) ⇒ *
        • .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 ⇒ *
    • .grayscale() ⇒ RawImage
    • .rgb() ⇒ RawImage
    • .rgba() ⇒ RawImage
    • .putAlpha(mask) ⇒ RawImage
    • .resize(width, height, options) ⇒ Promise.<RawImage>
    • .split() ⇒ Array.<RawImage>
    • .clone() ⇒ RawImage
    • .convert(numChannels) ⇒ RawImage
    • .save(path)
  • static
    • .read(input) ⇒ *
    • .fromCanvas(canvas) ⇒ RawImage
    • .fromURL(url) ⇒ Promise.<RawImage>
    • .fromBlob(blob) ⇒ Promise.<RawImage>
    • .fromTensor(tensor)

---

new RawImage(data, width, height, channels)

Create a new RawImage object.

Param	Type	Description
data	Uint8ClampedArray | Uint8Array	The pixel data.
width	number	The width of the image.
height	number	The height of the image.
channels	1 | 2 | 3 | 4	The number of channels.

---

rawImage.size ⇒ *

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

Kind: instance property of RawImage
Returns: * - 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.

Param	Type	Description
mask	RawImage	The 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.

Param	Type	Description
width	number	The width of the new image. null or -1 will preserve the aspect ratio.
height	number	The height of the new image. null or -1 will preserve the aspect ratio.
options	Object	Additional options for resizing.
[options.resample]	0 | 1 | 2 | 3 | 4 | 5 | string	The resampling method to use.

---

rawImage.split() ⇒ Array.<RawImage>

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.<RawImage> - 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.

Param	Type	Description
numChannels	number	The number of channels. Must be 1, 3, or 4.

---

rawImage.save(path)

Save the image to the given path.

Kind: instance method of RawImage

Param	Type	Description
path	string	The path to save the image to.

---

RawImage.read(input) ⇒ *

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

Kind: static method of RawImage
Returns: * - 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 

Param	Type
input	RawImage | 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.

Param	Type	Description
canvas	HTMLCanvasElement | OffscreenCanvas	The 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.

Param	Type	Description
url	string | URL	The 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.

Param	Type	Description
blob	Blob	The blob to read the image from.

---

RawImage.fromTensor(tensor)

Helper method to create a new Image from a tensor

Kind: static method of RawImage

Param	Type
tensor	Tensor

---

utils/image.load_image

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

Kind: static constant of utils/image

---

utils/image~CONTENT_TYPE_MAP

Mapping from file extensions to MIME types.

Kind: inner constant of utils/image

---