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Diffstat (limited to 'docs/content/en/content-management/image-processing/index.md')
-rw-r--r-- | docs/content/en/content-management/image-processing/index.md | 67 |
1 files changed, 33 insertions, 34 deletions
diff --git a/docs/content/en/content-management/image-processing/index.md b/docs/content/en/content-management/image-processing/index.md index 9efb3b6bf..e865b0846 100644 --- a/docs/content/en/content-management/image-processing/index.md +++ b/docs/content/en/content-management/image-processing/index.md @@ -4,7 +4,7 @@ description: "Image Page resources can be resized and cropped." date: 2018-01-24T13:10:00-05:00 linktitle: "Image Processing" categories: ["content management"] -keywords: [resources,images] +keywords: [resources, images] weight: 4004 draft: false toc: true @@ -28,7 +28,6 @@ To get all images in a [Page Bundle]({{< relref "/content-management/organizatio ## Image Processing Methods - The `image` resource implements the methods `Resize`, `Fit` and `Fill`, each returning the transformed image using the specified dimensions and processing options. The `image` resource also, since Hugo 0.58, implements the method `Exif` and `Filter`. ### Resize @@ -37,27 +36,29 @@ Resizes the image to the specified width and height. ```go // Resize to a width of 600px and preserve ratio -{{ $image := $resource.Resize "600x" }} +{{ $image := $resource.Resize "600x" }} // Resize to a height of 400px and preserve ratio -{{ $image := $resource.Resize "x400" }} +{{ $image := $resource.Resize "x400" }} // Resize to a width 600px and a height of 400px {{ $image := $resource.Resize "600x400" }} ``` ### Fit + Scale down the image to fit the given dimensions while maintaining aspect ratio. Both height and width are required. ```go -{{ $image := $resource.Fit "600x400" }} +{{ $image := $resource.Fit "600x400" }} ``` ### Fill + Resize and crop the image to match the given dimensions. Both height and width are required. ```go -{{ $image := $resource.Fill "600x400" }} +{{ $image := $resource.Fill "600x400" }} ``` ### Filter @@ -74,7 +75,7 @@ The above can also be written in a more functional style using pipes: {{ $img = $img | images.Filter (images.GaussianBlur 6) (images.Pixelate 8) }} ``` -The filters will be applied in the given order. +The filters will be applied in the given order. Sometimes it can be useful to create the filter chain once and then reuse it: @@ -94,7 +95,7 @@ Note that this is only suported for JPEG and TIFF images, so it's recommended to {{ with $img.Exif }} Date: {{ .Date }} Lat/Long: {{ .Lat}}/{{ .Long }} -Tags: +Tags: {{ range $k, $v := .Tags }} TAG: {{ $k }}: {{ $v }} {{ end }} @@ -104,14 +105,22 @@ TAG: {{ $k }}: {{ $v }} Or individually access EXIF data with dot access, e.g.: ```go-html-template -{{ with $img.Exif }} -Date: {{ .Date }} -Lat/Long: {{ .Lat }}/{{ .Long }} -Aperture: {{ .Tags.ApertureValue }} -Focal Length: {{ .Tags.FocalLength }} +{{ with $src.Exif }} + <ul> + {{ with .Date }}<li>Date: {{ .Format "January 02, 2006" }}</li>{{ end }} + {{ with .Tags.ApertureValue }}<li>Aperture: {{ lang.NumFmt 2 . }}</li>{{ end }} + {{ with .Tags.BrightnessValue }}<li>Brightness: {{ lang.NumFmt 2 . }}</li>{{ end }} + {{ with .Tags.ExposureTime }}<li>Exposure Time: {{ . }}</li>{{ end }} + {{ with .Tags.FNumber }}<li>F Number: {{ . }}</li>{{ end }} + {{ with .Tags.FocalLength }}<li>Focal Length: {{ . }}</li>{{ end }} + {{ with .Tags.ISOSpeedRatings }}<li>ISO Speed Ratings: {{ . }}</li>{{ end }} + {{ with .Tags.LensModel }}<li>Lens Model: {{ . }}</li>{{ end }} + </ul> {{ end }} ``` +Some fields may need to be formatted with [`lang.NumFmt`]({{< relref "functions/numfmt" >}}) function to prevent display like `Aperture: 2.278934289` instead of `Aperture: 2.28`. + #### Exif fields Date @@ -125,10 +134,6 @@ Long See [Image Processing Config](#image-processing-config) for how to configure what gets included in Exif. - - - - ## Image Processing Options In addition to the dimensions (e.g. `600x400`), Hugo supports a set of additional image options. @@ -148,6 +153,7 @@ For color codes, see https://www.google.com/search?q=color+picker **Note** that you also set a default background color to use, see [Image Processing Config](#image-processing-config). ### JPEG Quality + Only relevant for JPEG images, values 1 to 100 inclusive, higher is better. Default is 75. ```go @@ -155,14 +161,16 @@ Only relevant for JPEG images, values 1 to 100 inclusive, higher is better. Defa ``` ### Rotate + Rotates an image by the given angle counter-clockwise. The rotation will be performed first to get the dimensions correct. The main use of this is to be able to manually correct for [EXIF orientation](https://github.com/golang/go/issues/4341) of JPEG images. ```go {{ $image.Resize "600x r90" }} ``` -### Anchor -Only relevant for the `Fill` method. This is useful for thumbnail generation where the main motive is located in, say, the left corner. +### Anchor + +Only relevant for the `Fill` method. This is useful for thumbnail generation where the main motive is located in, say, the left corner. Valid are `Center`, `TopLeft`, `Top`, `TopRight`, `Left`, `Right`, `BottomLeft`, `Bottom`, `BottomRight`. ```go @@ -170,11 +178,12 @@ Valid are `Center`, `TopLeft`, `Top`, `TopRight`, `Left`, `Right`, `BottomLeft`, ``` ### Resample Filter -Filter used in resizing. Default is `Box`, a simple and fast resampling filter appropriate for downscaling. + +Filter used in resizing. Default is `Box`, a simple and fast resampling filter appropriate for downscaling. Examples are: `Box`, `NearestNeighbor`, `Linear`, `Gaussian`. -See https://github.com/disintegration/imaging for more. If you want to trade quality for faster processing, this may be a option to test. +See https://github.com/disintegration/imaging for more. If you want to trade quality for faster processing, this may be a option to test. ```go {{ $image.Resize "600x400 Gaussian" }} @@ -194,7 +203,6 @@ Valid values are `jpg`, `png`, `tif`, `bmp`, and `gif`. _The photo of the sunset used in the examples below is Copyright [Bjørn Erik Pedersen](https://commons.wikimedia.org/wiki/User:Bep) (Creative Commons Attribution-Share Alike 4.0 International license)_ - {{< imgproc sunset Resize "300x" />}} {{< imgproc sunset Fill "90x120 left" />}} @@ -205,12 +213,10 @@ _The photo of the sunset used in the examples below is Copyright [Bjørn Erik Pe {{< imgproc sunset Resize "300x q10" />}} - This is the shortcode used in the examples above: - {{< code file="layouts/shortcodes/imgproc.html" >}} -{{< readfile file="layouts/shortcodes/imgproc.html" >}} +{{< readfile file="layouts/shortcodes/imgproc.html" >}} {{< /code >}} And it is used like this: @@ -219,7 +225,6 @@ And it is used like this: {{</* imgproc sunset Resize "300x" /*/>}} ``` - {{% note %}} **Tip:** Note the self-closing shortcode syntax above. The `imgproc` shortcode can be called both with and without **inner content**. {{% /note %}} @@ -244,7 +249,7 @@ quality = 75 # Valid values are Smart, Center, TopLeft, Top, TopRight, Left, Right, BottomLeft, Bottom, BottomRight anchor = "smart" -# Default background color. +# Default background color. # Hugo will preserve transparency for target formats that supports it, # but will fall back to this color for JPEG. # Expects a standard HEX color string with 3 or 6 digits. @@ -281,15 +286,13 @@ By default, Hugo will use the [Smartcrop](https://github.com/muesli/smartcrop), An example using the sunset image from above: - {{< imgproc sunset Fill "200x200 smart" />}} - ## Image Processing Performance Consideration Processed images are stored below `<project-dir>/resources` (can be set with `resourceDir` config setting). This folder is deliberately placed in the project, as it is recommended to check these into source control as part of the project. These images are not "Hugo fast" to generate, but once generated they can be reused. -If you change your image settings (e.g. size), remove or rename images etc., you will end up with unused images taking up space and cluttering your project. +If you change your image settings (e.g. size), remove or rename images etc., you will end up with unused images taking up space and cluttering your project. To clean up, run: @@ -297,10 +300,6 @@ To clean up, run: hugo --gc ``` - {{% note %}} **GC** is short for **Garbage Collection**. {{% /note %}} - - - |