Add support for IIIF v3 tile-based output

docs/api-output.md

@@ -546,10 +546,10 @@ Use a `.zip` or `.szi` file extension with `toFile` to write to a compressed arc
     *   `options.depth` **[string][2]?** how deep to make the pyramid, possible values are `onepixel`, `onetile` or `one`, default based on layout.
     *   `options.skipBlanks` **[number][9]** threshold to skip tile generation, a value 0 - 255 for 8-bit images or 0 - 65535 for 16-bit images (optional, default `-1`)
     *   `options.container` **[string][2]** tile container, with value `fs` (filesystem) or `zip` (compressed file). (optional, default `'fs'`)
-    *   `options.layout` **[string][2]** filesystem layout, possible values are `dz`, `iiif`, `zoomify` or `google`. (optional, default `'dz'`)
+    *   `options.layout` **[string][2]** filesystem layout, possible values are `dz`, `iiif`, `iiif3`, `zoomify` or `google`. (optional, default `'dz'`)
     *   `options.centre` **[boolean][7]** centre image in tile. (optional, default `false`)
     *   `options.center` **[boolean][7]** alternative spelling of centre. (optional, default `false`)
-    *   `options.id` **[string][2]** when `layout` is `iiif`, sets the `@id` attribute of `info.json` (optional, default `'https://example.com/iiif'`)
+    *   `options.id` **[string][2]** when `layout` is `iiif`/`iiif3`, sets the `@id`/`id` attribute of `info.json` (optional, default `'https://example.com/iiif'`)
 
 ### Examples
 

docs/changelog.md

@@ -16,6 +16,8 @@ Requires libvips v8.12.1
 
 * Standardise HEIF `effort` option name, deprecate `speed`.
 
+* Add support for IIIF v3 tile-based output.
+
 * Expose control over CPU effort for palette-based PNG output.
   [#2541](https://github.com/lovell/sharp/issues/2541)
 

lib/output.js

@@ -930,10 +930,10 @@ function raw (options) {
  * @param {string} [options.depth] how deep to make the pyramid, possible values are `onepixel`, `onetile` or `one`, default based on layout.
  * @param {number} [options.skipBlanks=-1] threshold to skip tile generation, a value 0 - 255 for 8-bit images or 0 - 65535 for 16-bit images
  * @param {string} [options.container='fs'] tile container, with value `fs` (filesystem) or `zip` (compressed file).
- * @param {string} [options.layout='dz'] filesystem layout, possible values are `dz`, `iiif`, `zoomify` or `google`.
+ * @param {string} [options.layout='dz'] filesystem layout, possible values are `dz`, `iiif`, `iiif3`, `zoomify` or `google`.
  * @param {boolean} [options.centre=false] centre image in tile.
  * @param {boolean} [options.center=false] alternative spelling of centre.
- * @param {string} [options.id='https://example.com/iiif'] when `layout` is `iiif`, sets the `@id` attribute of `info.json`
+ * @param {string} [options.id='https://example.com/iiif'] when `layout` is `iiif`/`iiif3`, sets the `@id`/`id` attribute of `info.json`
  * @returns {Sharp}
  * @throws {Error} Invalid parameters
  */
@@ -968,10 +968,10 @@ function tile (options) {
     }
     // Layout
     if (is.defined(options.layout)) {
-      if (is.string(options.layout) && is.inArray(options.layout, ['dz', 'google', 'iiif', 'zoomify'])) {
+      if (is.string(options.layout) && is.inArray(options.layout, ['dz', 'google', 'iiif', 'iiif3', 'zoomify'])) {
         this.options.tileLayout = options.layout;
       } else {
-        throw is.invalidParameterError('layout', 'one of: dz, google, iiif, zoomify', options.layout);
+        throw is.invalidParameterError('layout', 'one of: dz, google, iiif, iiif3, zoomify', options.layout);
       }
     }
     // Angle of rotation,

test/unit/tile.js

@@ -830,7 +830,7 @@ describe('Tile', function () {
     });
   });
 
-  it('IIIF layout', function (done) {
+  it('IIIFv2 layout', function (done) {
     const name = 'output.iiif.info';
     const directory = fixtures.path(name);
     rimraf(directory, function () {
@@ -848,6 +848,7 @@ describe('Tile', function () {
           assert.strictEqual(3, info.channels);
           assert.strictEqual('number', typeof info.size);
           const infoJson = require(path.join(directory, 'info.json'));
+          assert.strictEqual('http://iiif.io/api/image/2/context.json', infoJson['@context']);
           assert.strictEqual(`${id}/${name}`, infoJson['@id']);
           fs.stat(path.join(directory, '0,0,256,256', '256,', '0', 'default.jpg'), function (err, stat) {
             if (err) throw err;
@@ -859,6 +860,37 @@ describe('Tile', function () {
     });
   });
 
+  it('IIIFv3 layout', function (done) {
+    const name = 'output.iiif3.info';
+    const directory = fixtures.path(name);
+    rimraf(directory, function () {
+      const id = 'https://sharp.test.com/iiif3';
+      sharp(fixtures.inputJpg)
+        .tile({
+          layout: 'iiif3',
+          id
+        })
+        .toFile(directory, function (err, info) {
+          if (err) throw err;
+          assert.strictEqual('dz', info.format);
+          assert.strictEqual(2725, info.width);
+          assert.strictEqual(2225, info.height);
+          assert.strictEqual(3, info.channels);
+          assert.strictEqual('number', typeof info.size);
+          const infoJson = require(path.join(directory, 'info.json'));
+          assert.strictEqual('http://iiif.io/api/image/3/context.json', infoJson['@context']);
+          assert.strictEqual('ImageService3', infoJson.type);
+          assert.strictEqual(`${id}/${name}`, infoJson.id);
+          fs.stat(path.join(directory, '0,0,256,256', '256,256,', '0', 'default.jpg'), function (err, stat) {
+            if (err) throw err;
+            assert.strictEqual(true, stat.isFile());
+            assert.strictEqual(true, stat.size > 0);
+            done();
+          });
+        });
+    });
+  });
+
   it('Write to ZIP container using file extension', function (done) {
     const container = fixtures.path('output.dz.container.zip');
     const extractTo = fixtures.path('output.dz.container');