64 lines
1.2 KiB
Go
64 lines
1.2 KiB
Go
package flutter_image_compress
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import (
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"image"
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"image/color"
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_ "image/gif"
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_ "image/jpeg"
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_ "image/png"
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"io"
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"os"
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"github.com/disintegration/imaging"
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"github.com/nfnt/resize"
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_ "golang.org/x/image/webp"
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)
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// Rotate image
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func RotateImage(img image.Image, degree int) image.Image {
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return imaging.Rotate(img, float64(degree), color.Transparent)
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}
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// Scale image
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func ScaleImage(reader io.Reader, minWidth, minHeight int32) (img image.Image, err error) {
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img, _, err = image.Decode(reader)
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if err != nil {
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return
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}
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w, h := calcTargetSize(img, minHeight, minHeight)
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img = resize.Resize(w, h, img, resize.Lanczos3)
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return
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}
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func calcTargetSize(img image.Image, minWidth, minHeight int32) (uint, uint) {
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srcW := float32(img.Bounds().Size().X)
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srcH := float32(img.Bounds().Size().Y)
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scaleW := srcW / float32(minWidth)
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scaleH := srcH / float32(minHeight)
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scale := scaleW
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if scaleH < scaleW {
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scale = scaleH
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}
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if scale < 1 {
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scale = 1
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}
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return uint(srcW / scale), uint(srcH / scale)
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}
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func pathExists(path string) (bool, error) {
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_, err := os.Stat(path)
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if err == nil {
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return true, nil
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}
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if os.IsNotExist(err) {
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return false, nil
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}
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return false, err
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}
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