Default TIFF predictor to horizontal to match libvips' behaviour

docs/api-input.md

@@ -87,6 +87,8 @@ Returns **Sharp**
 An advanced setting that switches the libvips access method to `VIPS_ACCESS_SEQUENTIAL`.
 This will reduce memory usage and can improve performance on some systems.
 
+The default behaviour _before_ function call is `false`, meaning the libvips access method is not sequential.
+
 **Parameters**
 
 -   `sequentialRead` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)

docs/api-output.md

@@ -140,7 +140,7 @@ Use these TIFF options for output image.
     -   `options.quality` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** quality, integer 1-100 (optional, default `80`)
     -   `options.force` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** force TIFF output, otherwise attempt to use input format (optional, default `true`)
     -   `options.compression` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** compression options: lzw, deflate, jpeg (optional, default `'jpeg'`)
-    -   `options.predictor` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** compression predictor options: none, horizontal, float (optional, default `'none'`)
+    -   `options.predictor` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** compression predictor options: none, horizontal, float (optional, default `'horizontal'`)
     -   `options.xres` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** horizontal resolution in pixels/mm (optional, default `1.0`)
     -   `options.yres` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** vertical resolution in pixels/mm (optional, default `1.0`)
     -   `options.squash` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** squash 8-bit images down to 1 bit (optional, default `false`)

docs/api-resize.md

@@ -160,6 +160,8 @@ Do not enlarge the output image if the input image width _or_ height are already
 This is equivalent to GraphicsMagick's `>` geometry option:
 "_change the dimensions of the image only if its width or height exceeds the geometry specification_".
 
+The default behaviour _before_ function call is `false`, meaning the image will be enlarged.
+
 **Parameters**
 
 -   `withoutEnlargement` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)

docs/changelog.md

@@ -22,6 +22,8 @@ Requires libvips v8.6.0.
   [#977](https://github.com/lovell/sharp/pull/977)
   [@jardakotesovec](https://github.com/jardakotesovec)
 
+* TIFF output: switch default predictor from 'none' to 'horizontal' to match libvips' behaviour.
+
 ### v0.18 - "*ridge*"
 
 Requires libvips v8.5.5.

lib/constructor.js

@@ -198,7 +198,7 @@ const Sharp = function (input, options) {
     webpNearLossless: false,
     tiffQuality: 80,
     tiffCompression: 'jpeg',
-    tiffPredictor: 'none',
+    tiffPredictor: 'horizontal',
     tiffSquash: false,
     tiffXres: 1.0,
     tiffYres: 1.0,

lib/output.js

@@ -214,7 +214,7 @@ function webp (options) {
  * @param {Number} [options.quality=80] - quality, integer 1-100
  * @param {Boolean} [options.force=true] - force TIFF output, otherwise attempt to use input format
  * @param {Boolean} [options.compression='jpeg'] - compression options: lzw, deflate, jpeg
- * @param {Boolean} [options.predictor='none'] - compression predictor options: none, horizontal, float
+ * @param {Boolean} [options.predictor='horizontal'] - compression predictor options: none, horizontal, float
  * @param {Number} [options.xres=1.0] - horizontal resolution in pixels/mm
  * @param {Number} [options.yres=1.0] - vertical resolution in pixels/mm
  * @param {Boolean} [options.squash=false] - squash 8-bit images down to 1 bit

src/pipeline.h

@@ -184,7 +184,7 @@ struct PipelineBaton {
     webpQuality(80),
     tiffQuality(80),
     tiffCompression(VIPS_FOREIGN_TIFF_COMPRESSION_JPEG),
-    tiffPredictor(VIPS_FOREIGN_TIFF_PREDICTOR_NONE),
+    tiffPredictor(VIPS_FOREIGN_TIFF_PREDICTOR_HORIZONTAL),
     tiffSquash(false),
     tiffXres(1.0),
     tiffYres(1.0),