<!-- Generated by documentation.js. Update this documentation by updating the source code. -->

## metadata

Fast access to (uncached) image metadata without decoding any compressed image data.
A `Promise` is returned when `callback` is not provided.

*   `format`: Name of decoder used to decompress image data e.g. `jpeg`, `png`, `webp`, `gif`, `svg`
*   `size`: Total size of image in bytes, for Stream and Buffer input only
*   `width`: Number of pixels wide (EXIF orientation is not taken into consideration)
*   `height`: Number of pixels high (EXIF orientation is not taken into consideration)
*   `space`: Name of colour space interpretation e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...][1]
*   `channels`: Number of bands e.g. `3` for sRGB, `4` for CMYK
*   `depth`: Name of pixel depth format e.g. `uchar`, `char`, `ushort`, `float` [...][2]
*   `density`: Number of pixels per inch (DPI), if present
*   `chromaSubsampling`: String containing JPEG chroma subsampling, `4:2:0` or `4:4:4` for RGB, `4:2:0:4` or `4:4:4:4` for CMYK
*   `isProgressive`: Boolean indicating whether the image is interlaced using a progressive scan
*   `pages`: Number of pages/frames contained within the image, with support for TIFF, HEIF, PDF, animated GIF and animated WebP
*   `pageHeight`: Number of pixels high each page in a multi-page image will be.
*   `loop`: Number of times to loop an animated image, zero refers to a continuous loop.
*   `delay`: Delay in ms between each page in an animated image, provided as an array of integers.
*   `pagePrimary`: Number of the primary page in a HEIF image
*   `levels`: Details of each level in a multi-level image provided as an array of objects, requires libvips compiled with support for OpenSlide
*   `subifds`: Number of Sub Image File Directories in an OME-TIFF image
*   `background`: Default background colour, if present, for PNG (bKGD) and GIF images, either an RGB Object or a single greyscale value
*   `compression`: The encoder used to compress an HEIF file, `av1` (AVIF) or `hevc` (HEIC)
*   `hasProfile`: Boolean indicating the presence of an embedded ICC profile
*   `hasAlpha`: Boolean indicating the presence of an alpha transparency channel
*   `orientation`: Number value of the EXIF Orientation header, if present
*   `exif`: Buffer containing raw EXIF data, if present
*   `icc`: Buffer containing raw [ICC][3] profile data, if present
*   `iptc`: Buffer containing raw IPTC data, if present
*   `xmp`: Buffer containing raw XMP data, if present
*   `tifftagPhotoshop`: Buffer containing raw TIFFTAG_PHOTOSHOP data, if present

### Parameters

*   `callback` **[Function][4]?** called with the arguments `(err, metadata)`

### Examples

```javascript
const image = sharp(inputJpg);
image
  .metadata()
  .then(function(metadata) {
    return image
      .resize(Math.round(metadata.width / 2))
      .webp()
      .toBuffer();
  })
  .then(function(data) {
    // data contains a WebP image half the width and height of the original JPEG
  });
```

Returns **([Promise][5]<[Object][6]> | Sharp)** 

## stats

Access to pixel-derived image statistics for every channel in the image.
A `Promise` is returned when `callback` is not provided.

*   `channels`: Array of channel statistics for each channel in the image. Each channel statistic contains
    *   `min` (minimum value in the channel)
    *   `max` (maximum value in the channel)
    *   `sum` (sum of all values in a channel)
    *   `squaresSum` (sum of squared values in a channel)
    *   `mean` (mean of the values in a channel)
    *   `stdev` (standard deviation for the values in a channel)
    *   `minX` (x-coordinate of one of the pixel where the minimum lies)
    *   `minY` (y-coordinate of one of the pixel where the minimum lies)
    *   `maxX` (x-coordinate of one of the pixel where the maximum lies)
    *   `maxY` (y-coordinate of one of the pixel where the maximum lies)
*   `isOpaque`: Is the image fully opaque? Will be `true` if the image has no alpha channel or if every pixel is fully opaque.
*   `entropy`: Histogram-based estimation of greyscale entropy, discarding alpha channel if any (experimental)
*   `sharpness`: Estimation of greyscale sharpness based on the standard deviation of a Laplacian convolution, discarding alpha channel if any (experimental)
*   `dominant`: Object containing most dominant sRGB colour based on a 4096-bin 3D histogram (experimental)

**Note**: Statistics are derived from the original input image. Any operations performed on the image must first be
written to a buffer in order to run `stats` on the result (see third example).

### Parameters

*   `callback` **[Function][4]?** called with the arguments `(err, stats)`

### Examples

```javascript
const image = sharp(inputJpg);
image
  .stats()
  .then(function(stats) {
     // stats contains the channel-wise statistics array and the isOpaque value
  });
```

```javascript
const { entropy, sharpness, dominant } = await sharp(input).stats();
const { r, g, b } = dominant;
```

```javascript
const image = sharp(input);
// store intermediate result
const part = await image.extract(region).toBuffer();
// create new instance to obtain statistics of extracted region
const stats = await sharp(part).stats();
```

Returns **[Promise][5]<[Object][6]>** 

[1]: https://libvips.github.io/libvips/API/current/VipsImage.html#VipsInterpretation

[2]: https://libvips.github.io/libvips/API/current/VipsImage.html#VipsBandFormat

[3]: https://www.npmjs.com/package/icc

[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function

[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise

[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object