hugo/resources/images/image.go
J. Ansorg e5856e61d8 resources: Support output image format in image operations
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
2019-09-21 16:50:27 +02:00

309 lines
6.6 KiB
Go

// Copyright 2019 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 (
"fmt"
"image"
"image/color"
"image/gif"
"image/jpeg"
"image/png"
"io"
"sync"
"github.com/gohugoio/hugo/media"
"github.com/gohugoio/hugo/resources/images/exif"
"github.com/disintegration/gift"
"golang.org/x/image/bmp"
"golang.org/x/image/tiff"
"github.com/gohugoio/hugo/common/hugio"
"github.com/pkg/errors"
)
func NewImage(f Format, proc *ImageProcessor, img image.Image, s Spec) *Image {
if img != nil {
return &Image{
Format: f,
Proc: proc,
Spec: s,
imageConfig: &imageConfig{
config: imageConfigFromImage(img),
configLoaded: true,
},
}
}
return &Image{Format: f, Proc: proc, Spec: s, imageConfig: &imageConfig{}}
}
type Image struct {
Format Format
Proc *ImageProcessor
Spec Spec
*imageConfig
}
func (i *Image) EncodeTo(conf ImageConfig, img image.Image, w io.Writer) error {
switch conf.TargetFormat {
case JPEG:
var rgba *image.RGBA
quality := conf.Quality
if nrgba, ok := img.(*image.NRGBA); ok {
if nrgba.Opaque() {
rgba = &image.RGBA{
Pix: nrgba.Pix,
Stride: nrgba.Stride,
Rect: nrgba.Rect,
}
}
}
if rgba != nil {
return jpeg.Encode(w, rgba, &jpeg.Options{Quality: quality})
}
return jpeg.Encode(w, img, &jpeg.Options{Quality: quality})
case PNG:
encoder := png.Encoder{CompressionLevel: png.DefaultCompression}
return encoder.Encode(w, img)
case GIF:
return gif.Encode(w, img, &gif.Options{
NumColors: 256,
})
case TIFF:
return tiff.Encode(w, img, &tiff.Options{Compression: tiff.Deflate, Predictor: true})
case BMP:
return bmp.Encode(w, img)
default:
return errors.New("format not supported")
}
}
// Height returns i's height.
func (i *Image) Height() int {
i.initConfig()
return i.config.Height
}
// Width returns i's width.
func (i *Image) Width() int {
i.initConfig()
return i.config.Width
}
func (i Image) WithImage(img image.Image) *Image {
i.Spec = nil
i.imageConfig = &imageConfig{
config: imageConfigFromImage(img),
configLoaded: true,
}
return &i
}
func (i Image) WithSpec(s Spec) *Image {
i.Spec = s
i.imageConfig = &imageConfig{}
return &i
}
func (i *Image) initConfig() error {
var err error
i.configInit.Do(func() {
if i.configLoaded {
return
}
var (
f hugio.ReadSeekCloser
config image.Config
)
f, err = i.Spec.ReadSeekCloser()
if err != nil {
return
}
defer f.Close()
config, _, err = image.DecodeConfig(f)
if err != nil {
return
}
i.config = config
})
if err != nil {
return errors.Wrap(err, "failed to load image config")
}
return nil
}
func NewImageProcessor(cfg Imaging) (*ImageProcessor, error) {
e := cfg.Exif
exifDecoder, err := exif.NewDecoder(
exif.WithDateDisabled(e.DisableDate),
exif.WithLatLongDisabled(e.DisableLatLong),
exif.ExcludeFields(e.ExcludeFields),
exif.IncludeFields(e.IncludeFields),
)
if err != nil {
return nil, err
}
return &ImageProcessor{
Cfg: cfg,
exifDecoder: exifDecoder,
}, nil
}
type ImageProcessor struct {
Cfg Imaging
exifDecoder *exif.Decoder
}
func (p *ImageProcessor) DecodeExif(r io.Reader) (*exif.Exif, error) {
return p.exifDecoder.Decode(r)
}
func (p *ImageProcessor) ApplyFiltersFromConfig(src image.Image, conf ImageConfig) (image.Image, error) {
var filters []gift.Filter
if conf.Rotate != 0 {
// Apply any rotation before any resize.
filters = append(filters, gift.Rotate(float32(conf.Rotate), color.Transparent, gift.NearestNeighborInterpolation))
}
switch conf.Action {
case "resize":
filters = append(filters, gift.Resize(conf.Width, conf.Height, conf.Filter))
case "fill":
if conf.AnchorStr == smartCropIdentifier {
bounds, err := p.smartCrop(src, conf.Width, conf.Height, conf.Filter)
if err != nil {
return nil, err
}
// First crop it, then resize it.
filters = append(filters, gift.Crop(bounds))
filters = append(filters, gift.Resize(conf.Width, conf.Height, conf.Filter))
} else {
filters = append(filters, gift.ResizeToFill(conf.Width, conf.Height, conf.Filter, conf.Anchor))
}
case "fit":
filters = append(filters, gift.ResizeToFit(conf.Width, conf.Height, conf.Filter))
default:
return nil, errors.Errorf("unsupported action: %q", conf.Action)
}
return p.Filter(src, filters...)
}
func (p *ImageProcessor) Filter(src image.Image, filters ...gift.Filter) (image.Image, error) {
g := gift.New(filters...)
dst := image.NewRGBA(g.Bounds(src.Bounds()))
g.Draw(dst, src)
return dst, nil
}
func (p *ImageProcessor) GetDefaultImageConfig(action string) ImageConfig {
return ImageConfig{
Action: action,
Quality: p.Cfg.Quality,
}
}
type Spec interface {
// Loads the image source.
ReadSeekCloser() (hugio.ReadSeekCloser, error)
}
// Format is an image file format.
type Format int
const (
JPEG Format = iota + 1
PNG
GIF
TIFF
BMP
)
// RequiresDefaultQuality returns if the default quality needs to be applied to images of this format
func (f Format) RequiresDefaultQuality() bool {
return f == JPEG
}
// DefaultExtension returns the default file extension of this format, starting with a dot.
// For example: .jpg for JPEG
func (f Format) DefaultExtension() string {
return f.MediaType().FullSuffix()
}
// MediaType returns the media type of this image, e.g. image/jpeg for JPEG
func (f Format) MediaType() media.Type {
switch f {
case JPEG:
return media.JPGType
case PNG:
return media.PNGType
case GIF:
return media.GIFType
case TIFF:
return media.TIFFType
case BMP:
return media.BMPType
default:
panic(fmt.Sprintf("%d is not a valid image format", f))
}
}
type imageConfig struct {
config image.Config
configInit sync.Once
configLoaded bool
}
func imageConfigFromImage(img image.Image) image.Config {
b := img.Bounds()
return image.Config{Width: b.Max.X, Height: b.Max.Y}
}
func ToFilters(in interface{}) []gift.Filter {
switch v := in.(type) {
case []gift.Filter:
return v
case []filter:
vv := make([]gift.Filter, len(v))
for i, f := range v {
vv[i] = f
}
return vv
case gift.Filter:
return []gift.Filter{v}
default:
panic(fmt.Sprintf("%T is not an image filter", in))
}
}