[@astrojs/image] support additional resize options (#4438)

* working draft

* more sharp params

* add changeset

* fix typing

* wip

* add missing docblocks

* update lock file

* remove enlargement and reduction resize options

* add tests

* Add docs

* support crop options in pictures

* cleanup

* define crop types in docs

* cleanup

* remove kernel option

Co-authored-by: Tony Sullivan <tony.f.sullivan@outlook.com>

.changeset/breezy-flowers-pay.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/image': minor
+---
+
+Support additional Sharp resize options

packages/integrations/image/README.md

@@ -205,7 +205,27 @@ The parameter can be a [named HTML color](https://www.w3schools.com/tags/ref_col
 color representation with 3 or 6 hexadecimal characters in the form `#123[abc]`, or an RGB definition in the form
 `rgb(100,100,100)`.
 
-### `<Picture /`>
+#### fit
+
+<p>
+
+**Type:** `'cover' | 'contain' | 'fill' | 'inside' | 'outside'` <br>
+**Default:** `'cover'`
+</p>
+
+How the image should be resized to fit both `height` and `width`.
+
+#### position
+
+<p>
+
+**Type:** `'top' | 'right top' | 'right' | 'right bottom' | 'bottom' | 'left bottom' | 'left' | 'left top' | 'north' | 'northeast' | 'east' | 'southeast' | 'south' | 'southwest' | 'west' | 'northwest' | 'center' | 'centre' | 'cover' | 'entropy' | 'attention'` <br>
+**Default:** `'centre'`
+</p>
+
+Position of the crop when fit is `cover` or `contain`.
+
+### `<Picture />`
 
 #### src
 
@@ -304,6 +324,28 @@ The parameter can be a [named HTML color](https://www.w3schools.com/tags/ref_col
 color representation with 3 or 6 hexadecimal characters in the form `#123[abc]`, or an RGB definition in the form
 `rgb(100,100,100)`.
 
+#### fit
+
+<p>
+
+**Type:** `'cover' | 'contain' | 'fill' | 'inside' | 'outside'` <br>
+**Default:** `'cover'`
+</p>
+
+How the image should be resized to fit both `height` and `width`.
+
+#### position
+
+<p>
+
+**Type:** `'top' | 'right top' | 'right' | 'right bottom' | 'bottom' | 'left bottom' | 'left' | 'left top' |
+  'north' | 'northeast' | 'east' | 'southeast' | 'south' | 'southwest' | 'west' | 'northwest' |
+  'center' | 'centre' | 'cover' | 'entropy' | 'attention'` <br>
+**Default:** `'centre'`
+</p>
+
+Position of the crop when fit is `cover` or `contain`.
+
 ### `getImage`
 
 This is the helper function used by the `<Image />` component to build `<img />` attributes for the transformed image. This helper can be used directly for more complex use cases that aren't currently supported by the `<Image />` component.

packages/integrations/image/components/Picture.astro

@@ -38,7 +38,9 @@ const {
 	sizes,
 	widths,
 	aspectRatio,
+	fit,
 	background,
+	position,
 	formats = ['avif', 'webp'],
 	loading = 'lazy',
 	decoding = 'async',
@@ -49,7 +51,15 @@ if (alt === undefined || alt === null) {
 	warnForMissingAlt();
 }
 
-const { image, sources } = await getPicture({ src, widths, formats, aspectRatio, background });
+const { image, sources } = await getPicture({
+	src,
+	widths,
+	formats,
+	aspectRatio,
+	fit,
+	background,
+	position,
+});
 ---
 
 <picture {...attrs}>

packages/integrations/image/src/lib/get-picture.ts

@@ -10,7 +10,9 @@ export interface GetPictureParams {
 	widths: number[];
 	formats: OutputFormat[];
 	aspectRatio?: TransformOptions['aspectRatio'];
+	fit?: TransformOptions['fit'];
 	background?: TransformOptions['background'];
+	position?: TransformOptions['position'];
 }
 
 export interface GetPictureResult {
@@ -41,7 +43,7 @@ async function resolveFormats({ src, formats }: GetPictureParams) {
 }
 
 export async function getPicture(params: GetPictureParams): Promise<GetPictureResult> {
-	const { src, widths } = params;
+	const { src, widths, fit, position, background } = params;
 
 	if (!src) {
 		throw new Error('[@astrojs/image] `src` is required');
@@ -64,8 +66,10 @@ export async function getPicture(params: GetPictureParams): Promise<GetPictureRe
 					src,
 					format,
 					width,
+					fit,
+					position,
+					background,
 					height: Math.round(width / aspectRatio!),
-					background: params.background,
 				});
 				return `${img.src} ${width}w`;
 			})
@@ -84,8 +88,10 @@ export async function getPicture(params: GetPictureParams): Promise<GetPictureRe
 		src,
 		width: Math.max(...widths),
 		aspectRatio,
+		fit,
+		position,
+		background,
 		format: allFormats[allFormats.length - 1],
-		background: params.background,
 	});
 
 	const sources = await Promise.all(allFormats.map((format) => getSource(format)));

packages/integrations/image/src/loaders/index.ts

@@ -21,6 +21,31 @@ export type ColorDefinition =
 	| `rgb(${number}, ${number}, ${number})`
 	| `rgb(${number},${number},${number})`;
 
+export type CropFit = 'cover' | 'contain' | 'fill' | 'inside' | 'outside';
+
+export type CropPosition =
+	| 'top'
+	| 'right top'
+	| 'right'
+	| 'right bottom'
+	| 'bottom'
+	| 'left bottom'
+	| 'left'
+	| 'left top'
+	| 'north'
+	| 'northeast'
+	| 'east'
+	| 'southeast'
+	| 'south'
+	| 'southwest'
+	| 'west'
+	| 'northwest'
+	| 'center'
+	| 'centre'
+	| 'cover'
+	| 'entropy'
+	| 'attention';
+
 export function isOutputFormat(value: string): value is OutputFormat {
 	return ['avif', 'jpeg', 'png', 'webp'].includes(value);
 }
@@ -105,6 +130,18 @@ export interface TransformOptions {
 	 * @example "rgb(255, 255, 255)" - an rgb color
 	 */
 	background?: ColorDefinition;
+	/**
+	 * How the image should be resized to fit both `height` and `width`.
+	 *
+	 * @default 'cover'
+	 */
+	fit?: CropFit;
+	/**
+	 * Position of the crop when fit is `cover` or `contain`.
+	 *
+	 * @default 'centre'
+	 */
+	position?: CropPosition;
 }
 
 export interface HostedImageService<T extends TransformOptions = TransformOptions> {

packages/integrations/image/src/loaders/sharp.ts

@@ -1,11 +1,12 @@
 import sharp from 'sharp';
-import { isAspectRatioString, isColor, isOutputFormat } from '../loaders/index.js';
+import { ColorDefinition, isAspectRatioString, isColor, isOutputFormat } from '../loaders/index.js';
 import type { OutputFormat, SSRImageService, TransformOptions } from './index.js';
 
 class SharpService implements SSRImageService {
 	async getImageAttributes(transform: TransformOptions) {
 		// strip off the known attributes
-		const { width, height, src, format, quality, aspectRatio, background, ...rest } = transform;
+		const { width, height, src, format, quality, aspectRatio, fit, position, background, ...rest } =
+			transform;
 
 		return {
 			...rest,
@@ -37,10 +38,18 @@ class SharpService implements SSRImageService {
 			searchParams.append('ar', transform.aspectRatio.toString());
 		}
 
+		if (transform.fit) {
+			searchParams.append('fit', transform.fit);
+		}
+
 		if (transform.background) {
 			searchParams.append('bg', transform.background);
 		}
 
+		if (transform.position) {
+			searchParams.append('p', encodeURI(transform.position));
+		}
+
 		return { searchParams };
 	}
 
@@ -76,11 +85,16 @@ class SharpService implements SSRImageService {
 			}
 		}
 
+		if (searchParams.has('fit')) {
+			transform.fit = searchParams.get('fit') as typeof transform.fit;
+		}
+
+		if (searchParams.has('p')) {
+			transform.position = decodeURI(searchParams.get('p')!) as typeof transform.position;
+		}
+
 		if (searchParams.has('bg')) {
-			const background = searchParams.get('bg')!;
+			transform.background = searchParams.get('bg') as ColorDefinition | undefined;
-			if (isColor(background)) {
-				transform.background = background;
-			}
 		}
 
 		return transform;
@@ -95,7 +109,14 @@ class SharpService implements SSRImageService {
 		if (transform.width || transform.height) {
 			const width = transform.width && Math.round(transform.width);
 			const height = transform.height && Math.round(transform.height);
-			sharpImage.resize(width, height);
+
+			sharpImage.resize({
+				width,
+				height,
+				fit: transform.fit,
+				position: transform.position,
+				background: transform.background,
+			});
 		}
 
 		// remove alpha channel and replace with background color if requested

packages/integrations/image/test/sharp.test.js

@@ -15,6 +15,8 @@ describe('Sharp service', () => {
 			['aspect ratio string', { src, aspectRatio: '16:9' }],
 			['aspect ratio float', { src, aspectRatio: 1.7 }],
 			['background color', { src, format: 'jpeg', background: '#333333' }],
+			['crop fit', { src, fit: 'cover' }],
+			['crop position', { src, position: 'center' }],
 		].forEach(([description, props]) => {
 			it(description, async () => {
 				const { searchParams } = await sharp.serializeTransform(props);
@@ -32,6 +34,8 @@ describe('Sharp service', () => {
 				verifyProp(props.width, 'w');
 				verifyProp(props.height, 'h');
 				verifyProp(props.aspectRatio, 'ar');
+				verifyProp(props.fit, 'fit');
+				verifyProp(props.position, 'p');
 				verifyProp(props.background, 'bg');
 			});
 		});
@@ -55,6 +59,8 @@ describe('Sharp service', () => {
 				`f=jpeg&bg=%23333333&href=${href}`,
 				{ src, format: 'jpeg', background: '#333333' },
 			],
+			['crop fit', `fit=contain&href=${href}`, { src, fit: 'contain' }],
+			['crop position', `p=right%20top&href=${href}`, { src, position: 'right top' }],
 		].forEach(([description, params, expected]) => {
 			it(description, async () => {
 				const searchParams = new URLSearchParams(params);