mirror of
https://github.com/lovell/sharp.git
synced 2025-07-09 10:30:15 +02:00
103 lines
4.5 KiB
Markdown
103 lines
4.5 KiB
Markdown
<!-- 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
|
|
- `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)
|
|
|
|
### 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
|
|
});
|
|
```
|
|
|
|
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
|