Docs: changelog and credit update for #2226

docs/api-output.md

@@ -190,10 +190,10 @@ Some of these options require the use of a globally-installed libvips compiled w
     -   `options.compressionLevel` **[number][9]** zlib compression level, 0-9 (optional, default `9`)
     -   `options.adaptiveFiltering` **[boolean][7]** use adaptive row filtering (optional, default `false`)
     -   `options.palette` **[boolean][7]** quantise to a palette-based image with alpha transparency support, requires libvips compiled with support for libimagequant (optional, default `false`)
-    -   `options.quality` **[number][9]** use the lowest number of colours needed to achieve given quality, requires libvips compiled with support for libimagequant (optional, default `100`)
+    -   `options.quality` **[number][9]** use the lowest number of colours needed to achieve given quality, sets `palette` to `true`, requires libvips compiled with support for libimagequant (optional, default `100`)
-    -   `options.colours` **[number][9]** maximum number of palette entries, requires libvips compiled with support for libimagequant (optional, default `256`)
+    -   `options.colours` **[number][9]** maximum number of palette entries, sets `palette` to `true`, requires libvips compiled with support for libimagequant (optional, default `256`)
-    -   `options.colors` **[number][9]** alternative spelling of `options.colours`, requires libvips compiled with support for libimagequant (optional, default `256`)
+    -   `options.colors` **[number][9]** alternative spelling of `options.colours`, sets `palette` to `true`, requires libvips compiled with support for libimagequant (optional, default `256`)
-    -   `options.dither` **[number][9]** level of Floyd-Steinberg error diffusion, requires libvips compiled with support for libimagequant (optional, default `1.0`)
+    -   `options.dither` **[number][9]** level of Floyd-Steinberg error diffusion, sets `palette` to `true`, requires libvips compiled with support for libimagequant (optional, default `1.0`)
     -   `options.force` **[boolean][7]** force PNG output, otherwise attempt to use input format (optional, default `true`)
 
 ### Examples

docs/changelog.md

@@ -10,6 +10,10 @@ Requires libvips v8.9.1
   [#2217](https://github.com/lovell/sharp/pull/2217)
   [@malice00](https://github.com/malice00)
 
+* Enable PNG palette when setting quality, colours, colors or dither.
+  [#2226](https://github.com/lovell/sharp/pull/2226)
+  [@romaleev](https://github.com/romaleev)
+
 ### v0.25.3 - 17th May 2020
 
 * Ensure libvips is initialised only once, improves worker thread safety.

docs/humans.txt

@@ -185,3 +185,6 @@ GitHub: https://github.com/dimadeveatii
 
 Name: Roland Asmann
 GitHub: https://github.com/malice00
+
+Name: Roman Malieiev
+GitHub: https://github.com/romaleev

lib/output.js

@@ -268,10 +268,10 @@ function jpeg (options) {
  * @param {number} [options.compressionLevel=9] - zlib compression level, 0-9
  * @param {boolean} [options.adaptiveFiltering=false] - use adaptive row filtering
  * @param {boolean} [options.palette=false] - quantise to a palette-based image with alpha transparency support, requires libvips compiled with support for libimagequant
- * @param {number} [options.quality=100] - use the lowest number of colours needed to achieve given quality, requires libvips compiled with support for libimagequant
+ * @param {number} [options.quality=100] - use the lowest number of colours needed to achieve given quality, sets `palette` to `true`, requires libvips compiled with support for libimagequant
- * @param {number} [options.colours=256] - maximum number of palette entries, requires libvips compiled with support for libimagequant
+ * @param {number} [options.colours=256] - maximum number of palette entries, sets `palette` to `true`, requires libvips compiled with support for libimagequant
- * @param {number} [options.colors=256] - alternative spelling of `options.colours`, requires libvips compiled with support for libimagequant
+ * @param {number} [options.colors=256] - alternative spelling of `options.colours`, sets `palette` to `true`, requires libvips compiled with support for libimagequant
- * @param {number} [options.dither=1.0] - level of Floyd-Steinberg error diffusion, requires libvips compiled with support for libimagequant
+ * @param {number} [options.dither=1.0] - level of Floyd-Steinberg error diffusion, sets `palette` to `true`, requires libvips compiled with support for libimagequant
  * @param {boolean} [options.force=true] - force PNG output, otherwise attempt to use input format
  * @returns {Sharp}
  * @throws {Error} Invalid options