74 lines
1.9 KiB
Go
74 lines
1.9 KiB
Go
package images
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import (
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"fmt"
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"image"
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"github.com/nfnt/resize"
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"github.com/oliamb/cutter"
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"github.com/ethereum/go-ethereum/log"
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)
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func Resize(size ResizeDimension, img image.Image) image.Image {
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var width, height uint
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switch {
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case img.Bounds().Max.X == img.Bounds().Max.Y:
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width, height = uint(size), uint(size)
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case img.Bounds().Max.X > img.Bounds().Max.Y:
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width, height = 0, uint(size)
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default:
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width, height = uint(size), 0
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}
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log.Info("resizing", "size", size, "width", width, "height", height)
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return resize.Resize(width, height, img, resize.Bilinear)
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}
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func Crop(img image.Image, rect image.Rectangle) (image.Image, error) {
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if img.Bounds().Max.X < rect.Max.X || img.Bounds().Max.Y < rect.Max.Y {
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return nil, fmt.Errorf(
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"crop dimensions out of bounds of image, image width '%dpx' & height '%dpx'; crop bottom right coordinate at X '%dpx' Y '%dpx'",
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img.Bounds().Max.X, img.Bounds().Max.Y,
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rect.Max.X, rect.Max.Y,
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)
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}
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return cutter.Crop(img, cutter.Config{
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Width: rect.Dx(),
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Height: rect.Dy(),
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Anchor: rect.Min,
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})
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}
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// CropImage takes an image, usually downloaded from a URL
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// If the image is square, the full image is returned
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// It the image is rectangular, the largest central square is returned
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// calculations at _docs/image-center-crop-calculations.png
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func CropCenter(img image.Image) (image.Image, error) {
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var cropRect image.Rectangle
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maxBounds := img.Bounds().Max
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if maxBounds.X == maxBounds.Y {
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return img, nil
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}
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if maxBounds.X > maxBounds.Y {
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// the final output should be YxY
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cropRect = image.Rectangle{
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Min: image.Point{X: maxBounds.X/2 - maxBounds.Y/2, Y: 0},
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Max: image.Point{X: maxBounds.X/2 + maxBounds.Y/2, Y: maxBounds.Y},
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}
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} else {
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// the final output should be XxX
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cropRect = image.Rectangle{
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Min: image.Point{X: 0, Y: maxBounds.Y/2 - maxBounds.X/2},
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Max: image.Point{X: maxBounds.X, Y: maxBounds.Y/2 + maxBounds.X/2},
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}
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}
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return Crop(img, cropRect)
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}
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