resources/images: Create AutoOrient image filter

Closes #11717

docs/content/en/functions/images/AutoOrient.md

@@ -0,0 +1,52 @@
+---
+title: images.AutoOrient
+description: Returns an image filter that rotates and flips an image as needed per its EXIF orientation tag.
+categories: []
+keywords: []
+action:
+  aliases: []
+  related:
+    - functions/images/Filter
+    - methods/resource/Filter
+  returnType: images.filter
+  signatures: [images.AutoOrient]
+toc: true
+---
+
+{{< new-in 0.122.0 >}}
+
+## Usage
+
+Create the filter:
+
+```go-html-template
+{{ $filter := images.AutoOrient }}
+```
+
+{{% include "functions/images/_common/apply-image-filter.md" %}}
+
+{{% note %}}
+When using with other filters, specify `images.AutoOrient` first.
+{{% /note %}}
+
+```go-html-template
+{{ $filters := slice
+  images.AutoOrient
+  (images.Process "resize 200x")
+}}
+{{ with resources.Get "images/original.jpg" }}
+  {{ with images.Filter $filters . }}
+    <img src="{{ .RelPermalink }}" width="{{ .Width }}" height="{{ .Height }}" alt="">
+  {{ end }}
+{{ end }}
+```
+
+## Example
+
+{{< img
+  src="images/examples/landscape-exif-orientation-5.jpg"
+  alt="Zion National Park"
+  filter="AutoOrient"
+  filterArgs=""
+  example=true
+>}}

docs/layouts/shortcodes/img.html

@@ -0,0 +1,379 @@
+{{- /*
+Renders the given image using the given filter, if any.
+
+@param {string} src The path to the image which must be a remote, page, or global resource.
+@param {string} [filter] The filter to apply to the image (case-insensitive).
+@param {string} [filterArgs] A comma-delimited list of arguments to pass to the filter.
+@param {bool} [example=false] If true, renders a before/after example.
+@param {int} [exampleWidth=384] Image width, in pixels, when rendering a before/after example.
+
+@returns {template.HTML}
+
+@examples
+
+  {{< img src="zion-national-park.jpg" >}}
+
+  {{< img src="zion-national-park.jpg" alt="Zion National Park" >}}
+
+  {{< img
+    src="zion-national-park.jpg"
+    alt="Zion National Park"
+    filter="grayscale"
+  >}}
+
+  {{< img
+    src="zion-national-park.jpg"
+    alt="Zion National Park"
+    filter="process"
+    filterArgs="resize 400x webp"
+  >}}
+
+  {{< img
+    src="zion-national-park.jpg"
+    alt="Zion National Park"
+    filter="colorize"
+    filterArgs="180,50,20"
+  >}}
+
+  {{< img
+    src="zion-national-park.jpg"
+    alt="Zion National Park"
+    filter="grayscale"
+    example=true
+  >}}
+
+  {{< img
+    src="zion-national-park.jpg"
+    alt="Zion National Park"
+    filter="grayscale"
+    example=true
+    exampleWidth=400
+  >}}
+
+  When using the text filter, provide the arguments in this order:
+
+    0. The text
+    1. The horizontal offset, in pixels, relative to the left of the image (default 20)
+    2. The vertical offset, in pixels, relative to the top of the image (default 20)
+    3. The font size in pixels (default 64)
+    4. The line height (default 1.2)
+    5. The font color (default #ffffff)
+
+  {{< img
+    src="images/examples/zion-national-park.jpg"
+    alt="Zion National Park"
+    filter="Text"
+    filterArgs="Zion National Park,25,250,56"
+    example=true
+  >}}
+
+  When using the padding filter, provide all arguments in this order:
+
+  0. Padding top
+  1. Padding right
+  2. Padding bottom
+  3. Padding right
+  4. Canvas color
+
+  {{< img
+    src="images/examples/zion-national-park.jpg"
+    alt="Zion National Park"
+    filter="Padding"
+    filterArgs="20,50,20,50,#0705"
+    example=true
+  >}}
+
+*/}}
+
+{{- /* Initialize. */}}
+{{- $alt := "" }}
+{{- $src := "" }}
+{{- $filter := "" }}
+{{- $filterArgs := slice }}
+{{- $example := false }}
+{{- $exampleWidth := 384 }}
+
+{{- /* Default values to use with the text filter. */}}
+{{ $textFilterOpts := dict
+  "xOffset" 20
+  "yOffset" 20
+  "fontSize" 64
+  "lineHeight" 1.2
+  "fontColor" "#ffffff"
+  "fontPath" "https://github.com/google/fonts/raw/main/ofl/lato/Lato-Regular.ttf"
+}}
+
+{{- /* Get and validate parameters. */}}
+{{- with .Get "alt" }}
+  {{- $alt = .}}
+{{- end }}
+
+{{- with .Get "src" }}
+  {{- $src = . }}
+{{- else }}
+  {{- errorf "The %q shortcode requires a file parameter. See %s" .Name .Position }}
+{{- end }}
+
+{{- with .Get "filter" }}
+  {{- $filter = . | lower }}
+{{- end }}
+
+{{- $validFilters := slice
+  "autoorient" "brightness" "colorbalance" "colorize" "contrast" "gamma"
+  "gaussianblur" "grayscale" "hue" "invert" "none" "opacity" "overlay"
+  "padding" "pixelate" "process" "saturation" "sepia" "sigmoid" "text"
+  "unsharpmask"
+}}
+
+{{- with $filter }}
+  {{- if not (in $validFilters .) }}
+    {{- errorf "The filter passed to the %q shortcode is invalid. The filter must be one of %s. See %s" $.Name (delimit $validFilters ", " ", or ") $.Position }}
+  {{- end }}
+{{- end }}
+
+{{- with .Get "filterArgs" }}
+  {{- $filterArgs = split . "," }}
+  {{- $filterArgs = apply $filterArgs "trim" "." " " }}
+{{- end }}
+
+{{- if in (slice "false" false 0) (.Get "example") }}
+  {{- $example = false }}
+{{- else if in (slice "true" true 1) (.Get "example")}}
+  {{- $example = true }}
+{{- end }}
+
+{{- with .Get "exampleWidth" }}
+  {{- $exampleWidth = . | int }}
+{{- end }}
+
+{{- /* Get image. */}}
+{{- $ctx := dict "page" .Page "src" $src "name" .Name "position" .Position }}
+{{- $i := partial "inline/get-resource.html" $ctx }}
+
+{{- /* Resize if rendering before/after examples. */}}
+{{- if $example }}
+  {{- $i = $i.Resize (printf "%dx" $exampleWidth) }}
+{{- end }}
+
+{{- /* Create filter. */}}
+{{- $f := "" }}
+{{- $ctx := dict "filter" $filter "args" $filterArgs "name" .Name "position" .Position }}
+{{- if eq $filter "autoorient" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 0) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $f = images.AutoOrient }}
+{{- else if eq $filter "brightness" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "percentage" "argValue" (index $filterArgs 0) "min" -100 "max" 100) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.Brightness (index $filterArgs 0) }}
+{{- else if eq $filter "colorbalance" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 3) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "percentage red" "argValue" (index $filterArgs 0) "min" -100 "max" 500) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $ctx = merge $ctx (dict "argName" "percentage green" "argValue" (index $filterArgs 1) "min" -100 "max" 500) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $ctx = merge $ctx (dict "argName" "percentage blue" "argValue" (index $filterArgs 2) "min" -100 "max" 500) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.ColorBalance (index $filterArgs 0) (index $filterArgs 1) (index $filterArgs 2) }}
+{{- else if eq $filter "colorize" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 3) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "hue" "argValue" (index $filterArgs 0) "min" 0 "max" 360) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $ctx = merge $ctx (dict "argName" "saturation" "argValue" (index $filterArgs 1) "min" 0 "max" 100) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $ctx = merge $ctx (dict "argName" "percentage" "argValue" (index $filterArgs 2) "min" 0 "max" 100) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.Colorize (index $filterArgs 0) (index $filterArgs 1) (index $filterArgs 2) }}
+{{- else if eq $filter "contrast" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "percentage" "argValue" (index $filterArgs 0) "min" -100 "max" 100) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.Contrast (index $filterArgs 0) }}
+{{- else if eq $filter "gamma" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "gamma" "argValue" (index $filterArgs 0) "min" 0 "max" 100) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.Gamma (index $filterArgs 0) }}
+{{- else if eq $filter "gaussianblur" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "sigma" "argValue" (index $filterArgs 0) "min" 0 "max" 1000) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.GaussianBlur (index $filterArgs 0) }}
+{{- else if eq $filter "grayscale" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 0) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $f = images.Grayscale }}
+{{- else if eq $filter "hue" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "shift" "argValue" (index $filterArgs 0) "min" -180 "max" 180) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.Hue (index $filterArgs 0) }}
+{{- else if eq $filter "invert" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 0) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $f = images.Invert }}
+{{- else if eq $filter "opacity" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "opacity" "argValue" (index $filterArgs 0) "min" 0 "max" 1) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.Opacity (index $filterArgs 0) }}
+{{- else if eq $filter "overlay" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 3) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $ctx := dict "src" (index $filterArgs 0) "name" .Name "position" .Position }}
+  {{- $overlayImg := partial "inline/get-resource.html" $ctx }}
+  {{- $f = images.Overlay $overlayImg (index $filterArgs 1 | float ) (index $filterArgs 2 | float) }}
+{{- else if eq $filter "padding" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 5) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $f = images.Padding
+    (index $filterArgs 0 | int)
+    (index $filterArgs 1 | int)
+    (index $filterArgs 2 | int)
+    (index $filterArgs 3 | int)
+    (index $filterArgs 4)
+  }}
+{{- else if eq $filter "pixelate" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "size" "argValue" (index $filterArgs 0) "min" 0 "max" 1000) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.Pixelate (index $filterArgs 0) }}
+{{- else if eq $filter "process" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $f = images.Process (index $filterArgs 0) }}
+{{- else if eq $filter "saturation" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "percentage" "argValue" (index $filterArgs 0) "min" -100 "max" 500) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.Saturation (index $filterArgs 0) }}
+{{- else if eq $filter "sepia" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "percentage" "argValue" (index $filterArgs 0) "min" 0 "max" 100) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.Sepia (index $filterArgs 0) }}
+{{- else if eq $filter "sigmoid" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 2) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "midpoint" "argValue" (index $filterArgs 0) "min" 0 "max" 1) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $ctx = merge $ctx (dict "argName" "factor" "argValue" (index $filterArgs 1) "min" -10 "max" 10) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.Sigmoid (index $filterArgs 0) (index $filterArgs 1) }}
+{{- else if eq $filter "text" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 1) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $ctx := dict "src" $textFilterOpts.fontPath "name" .Name "position" .Position }}
+  {{- $font := or (partial "inline/get-resource.html" $ctx) }}
+  {{- $fontSize := or (index $filterArgs 3 | int) $textFilterOpts.fontSize }}
+  {{- $lineHeight := math.Max (or (index $filterArgs 4 | float) $textFilterOpts.lineHeight) 1 }}
+  {{- $opts := dict
+    "x" (or (index $filterArgs 1 | int) $textFilterOpts.xOffset)
+    "y" (or (index $filterArgs 2 | int) $textFilterOpts.yOffset)
+    "size" $fontSize
+    "linespacing" (mul (sub $lineHeight 1) $fontSize)
+    "color" (or (index $filterArgs 5) $textFilterOpts.fontColor)
+    "font" $font
+  }}
+  {{- $f = images.Text (index $filterArgs 0) $opts }}
+{{- else if eq $filter "unsharpmask" }}
+  {{- $ctx = merge $ctx (dict "argsRequired" 3) }}
+  {{- template "validate-arg-count" $ctx }}
+  {{- $filterArgs = apply $filterArgs "float" "." }}
+  {{- $ctx = merge $ctx (dict "argName" "sigma" "argValue" (index $filterArgs 0) "min" 0 "max" 500) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $ctx = merge $ctx (dict "argName" "amount" "argValue" (index $filterArgs 1) "min" 0 "max" 100) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $ctx = merge $ctx (dict "argName" "threshold" "argValue" (index $filterArgs 2) "min" 0 "max" 1) }}
+  {{- template "validate-arg-value" $ctx }}
+  {{- $f = images.UnsharpMask (index $filterArgs 0) (index $filterArgs 1) (index $filterArgs 2) }}
+{{- end }}
+
+{{- /* Apply filter. */}}
+{{- $fi := $i }}
+{{- with $f }}
+  {{- $fi = $i.Filter . }}
+{{- end }}
+
+{{- /* Render. */}}
+{{- if $example }}
+  <p>Original</p>
+  <img class='di ba b--black-20' style="width: initial;" src="{{ $i.RelPermalink }}" alt="{{ $alt }}">
+  <p>Processed</p>
+  <img class='di ba b--black-20' style="width: initial;" src="{{ $fi.RelPermalink }}" alt="{{ $alt }}">
+{{- else -}}
+  <img class='di' style="width: initial;" src="{{ $fi.RelPermalink }}" alt="{{ $alt }}">
+{{- end }}
+
+{{- define "validate-arg-count" }}
+  {{- $msg := "When using the %q filter, the %q shortcode requires an args parameter with %d %s. See %s" }}
+  {{- if lt (len .args) .argsRequired }}
+    {{- $text := "values" }}
+    {{- if eq 1 .argsRequired }}
+      {{- $text = "value" }}
+    {{- end }}
+    {{- errorf $msg .filter .name .argsRequired $text .position }}
+  {{- end }}
+{{- end }}
+
+{{- define "validate-arg-value" }}
+  {{- $msg := "The %q argument passed to the %q shortcode is invalid. Expected a value in the range [%v,%v], but received %v. See %s" }}
+  {{- if or (lt .argValue .min) (gt .argValue .max) }}
+    {{- errorf $msg .argName .name .min .max .argValue .position }}
+  {{- end }}
+{{- end }}
+
+{{- define "partials/inline/get-resource.html" }}
+  {{- $r := "" }}
+  {{- $u := urls.Parse .src }}
+  {{- $msg := "The %q shortcode was unable to resolve %s. See %s" }}
+  {{- if $u.IsAbs }}
+    {{- with resources.GetRemote $u.String }}
+      {{- with .Err }}
+        {{- errorf "%s" }}
+      {{- else }}
+        {{- /* This is a remote resource. */}}
+        {{- $r = . }}
+      {{- end }}
+    {{- else }}
+      {{- errorf $msg $.name $u.String $.position }}
+    {{- end }}
+  {{- else }}
+    {{- with .page.Resources.Get (strings.TrimPrefix "./" $u.Path) }}
+      {{- /* This is a page resource. */}}
+      {{- $r = . }}
+    {{- else }}
+      {{- with resources.Get $u.Path }}
+        {{- /* This is a global resource. */}}
+        {{- $r = . }}
+      {{- else }}
+        {{- errorf $msg $.name $u.Path $.position }}
+      {{- end }}
+    {{- end }}
+  {{- end }}
+  {{- return $r}}
+{{- end -}}

resources/image.go

@@ -279,8 +279,8 @@ func (i *imageResource) Filter(filters ...any) (images.ImageResource, error) {
 	}
 
 	return i.doWithImageConfig(conf, func(src image.Image) (image.Image, error) {
-		filters := gfilters
+		var filters []gift.Filter
-		for j, f := range gfilters {
+		for _, f := range gfilters {
 			f = images.UnwrapFilter(f)
 			if specProvider, ok := f.(images.ImageProcessSpecProvider); ok {
 				processSpec := specProvider.ImageProcessSpec()
@@ -293,10 +293,14 @@ func (i *imageResource) Filter(filters ...any) (images.ImageResource, error) {
 				if err != nil {
 					return nil, err
 				}
-				// Replace the filter with the new filters.
+				filters = append(filters, pFilters...)
-				// This slice will be empty if this is just a format conversion.
+			} else if orientationProvider, ok := f.(images.ImageFilterFromOrientationProvider); ok {
-				filters = append(filters[:j], append(pFilters, filters[j+1:]...)...)
+				tf := orientationProvider.AutoOrient(i.Exif())
-
+				if tf != nil {
+					filters = append(filters, tf)
+				}
+			} else {
+				filters = append(filters, f)
 			}
 		}
 		return i.Proc.Filter(src, filters...)

resources/images/auto_orient.go

@@ -0,0 +1,60 @@
+// Copyright 2023 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package images
+
+import (
+	"image"
+	"image/draw"
+
+	"github.com/disintegration/gift"
+	"github.com/gohugoio/hugo/resources/images/exif"
+)
+
+var _ gift.Filter = (*autoOrientFilter)(nil)
+
+var transformationFilters = map[int]gift.Filter{
+	2: gift.FlipHorizontal(),
+	3: gift.Rotate180(),
+	4: gift.FlipVertical(),
+	5: gift.Transpose(),
+	6: gift.Rotate270(),
+	7: gift.Transverse(),
+	8: gift.Rotate90(),
+}
+
+type autoOrientFilter struct{}
+
+type ImageFilterFromOrientationProvider interface {
+	AutoOrient(exifInfo *exif.ExifInfo) gift.Filter
+}
+
+func (f autoOrientFilter) Draw(dst draw.Image, src image.Image, options *gift.Options) {
+	panic("not supported")
+}
+
+func (f autoOrientFilter) Bounds(srcBounds image.Rectangle) image.Rectangle {
+	panic("not supported")
+}
+
+func (f autoOrientFilter) AutoOrient(exifInfo *exif.ExifInfo) gift.Filter {
+	if exifInfo != nil {
+		if orientation, ok := exifInfo.Tags["Orientation"].(int); ok {
+			if filter, ok := transformationFilters[orientation]; ok {
+				return filter
+			}
+		}
+	}
+
+	return nil
+}

resources/images/filters.go

@@ -174,6 +174,14 @@ func (*Filters) Padding(args ...any) gift.Filter {
 	}
 }
 
+// AutoOrient creates a filter that rotates and flips an image as needed per
+// its EXIF orientation tag.
+func (*Filters) AutoOrient() gift.Filter {
+	return filter{
+		Filter: autoOrientFilter{},
+	}
+}
+
 // Brightness creates a filter that changes the brightness of an image.
 // The percentage parameter must be in range (-100, 100).
 func (*Filters) Brightness(percentage any) gift.Filter {