This allows for constructs like:
```
{{ $filters := slice (images.GaussianBlur 8) (images.Grayscale) (images.Process "jpg q30 resize 200x") }}
{{ $img = $img | images.Filter $filters }}
```
Note that the `action` option in `images.Process` is optional (`resize` in the example above), so you can use the above to just set the target format, e.g.:
```
{{ $filters := slice (images.GaussianBlur 8) (images.Grayscale) (images.Process "jpg") }}
{{ $img = $img | images.Filter $filters }}
```
Fixes#8439
Which supports all the existing actions: resize, crop, fit, fill.
But it also allows plain format conversions:
```
{{ $img = $img.Process "webp" }}
```
Which will be a simple re-encoding of the source image.
Fixes#11483
Primary motivation is documentation, but it will also hopefully simplify the code.
Also,
* Lower case the default output format names; this is in line with the custom ones (map keys) and how
it's treated all the places. This avoids doing `stringds.EqualFold` everywhere.
Closes#10896Closes#10620
* Add file context to minifier errors when publishing
* Misc fixes (see issues)
* Allow custom server error template in layouts/server/error.html
To get to this, this commit also cleans up and simplifies the code surrounding errors and files. This also removes the usage of `github.com/pkg/errors`, mostly because of https://github.com/pkg/errors/issues/223 -- but also because most of this is now built-in to Go.
Fixes#9852Fixes#9857Fixes#9863
Introduces the Crop method for image processing which implements gift.CropToSize. Also allows a smartCrop without resizing, and updates the documentation.
Fixes#9499
So we can use it and output.Format as map key etc.
This commit also fixes the media.Type implementation so it does not need to mutate itself to handle different suffixes for the same MIME type, e.g. jpg vs. jpeg.
This means that there are no Suffix or FullSuffix on media.Type anymore.
Fixes#8317Fixes#8324
This allows for constructs ala:
```
{{ $overlay := $img.Filter (images.Overlay $logo 50 50 )}}
```
Or:
```
{{ $logoFilter := (images.Overlay $logo 50 50 ) }}
{{ $overlay := $img | images.Filter $logoFilter }}
```
Which will overlay the logo in the top left corner (x=50, y=50) of `$img`.
Fixes#8057Fixes#4595
Updates #6731
The image format is defined as the image extension of the known formats,
excluding the dot.
All of 'img.Resize "600x jpeg"', 'img.Resize "600x jpg"',
and 'img.Resize "600x png"' are valid format definitions.
If the target format is defined in the operation definition string,
then the converted image will be stored in this format. Permalinks and
media type are updated correspondingly.
Unknown image extensions in the operation definition have not effect.
See #6298
This commit pulls most of the image related logic into its own package, to make it easier to reason about and extend.
This is also a rewrite of the transformation logic used in Hugo Pipes, mostly to allow constructs like the one below:
{{ ($myimg | fingerprint ).Width }}
Fixes#5903Fixes#6234Fixes#6266
