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Diffstat (limited to 'resources/images/smartcrop.go')
-rw-r--r-- | resources/images/smartcrop.go | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/resources/images/smartcrop.go b/resources/images/smartcrop.go new file mode 100644 index 000000000..0b35b8280 --- /dev/null +++ b/resources/images/smartcrop.go @@ -0,0 +1,75 @@ +// 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 ( + "image" + + "github.com/disintegration/imaging" + "github.com/muesli/smartcrop" +) + +const ( + // Do not change. + // TODO(bep) image unexport + SmartCropIdentifier = "smart" + + // This is just a increment, starting on 1. If Smart Crop improves its cropping, we + // need a way to trigger a re-generation of the crops in the wild, so increment this. + smartCropVersionNumber = 1 +) + +func newSmartCropAnalyzer(filter imaging.ResampleFilter) smartcrop.Analyzer { + return smartcrop.NewAnalyzer(imagingResizer{filter: filter}) +} + +// Needed by smartcrop +type imagingResizer struct { + filter imaging.ResampleFilter +} + +func (r imagingResizer) Resize(img image.Image, width, height uint) image.Image { + return imaging.Resize(img, int(width), int(height), r.filter) +} + +func smartCrop(img image.Image, width, height int, anchor imaging.Anchor, filter imaging.ResampleFilter) (*image.NRGBA, error) { + if width <= 0 || height <= 0 { + return &image.NRGBA{}, nil + } + + srcBounds := img.Bounds() + srcW := srcBounds.Dx() + srcH := srcBounds.Dy() + + if srcW <= 0 || srcH <= 0 { + return &image.NRGBA{}, nil + } + + if srcW == width && srcH == height { + return imaging.Clone(img), nil + } + + smart := newSmartCropAnalyzer(filter) + + rect, err := smart.FindBestCrop(img, width, height) + if err != nil { + return nil, err + } + + b := img.Bounds().Intersect(rect) + + cropped := imaging.Crop(img, b) + + return imaging.Resize(cropped, width, height, filter), nil +} |