|
|
package minio
|
|
|
|
|
|
import (
|
|
|
"image"
|
|
|
_ "image/gif"
|
|
|
_ "image/jpeg"
|
|
|
_ "image/png"
|
|
|
"io"
|
|
|
|
|
|
_ "golang.org/x/image/bmp"
|
|
|
_ "golang.org/x/image/tiff"
|
|
|
_ "golang.org/x/image/webp"
|
|
|
)
|
|
|
|
|
|
const (
|
|
|
formatPng = "png"
|
|
|
formatJpeg = "jpeg"
|
|
|
formatJpg = "jpg"
|
|
|
formatGif = "gif"
|
|
|
)
|
|
|
|
|
|
func ImageStat(reader io.Reader) (image.Image, string, error) {
|
|
|
return image.Decode(reader)
|
|
|
}
|
|
|
|
|
|
func ImageWidthHeight(img image.Image) (int, int) {
|
|
|
bounds := img.Bounds().Max
|
|
|
return bounds.X, bounds.Y
|
|
|
}
|
|
|
|
|
|
func resizeImage(img image.Image, maxWidth, maxHeight int) image.Image {
|
|
|
bounds := img.Bounds()
|
|
|
imgWidth := bounds.Max.X
|
|
|
imgHeight := bounds.Max.Y
|
|
|
|
|
|
// 计算缩放比例
|
|
|
scaleWidth := float64(maxWidth) / float64(imgWidth)
|
|
|
scaleHeight := float64(maxHeight) / float64(imgHeight)
|
|
|
|
|
|
// 如果都为0，则不缩放，返回原始图片
|
|
|
if maxWidth == 0 && maxHeight == 0 {
|
|
|
return img
|
|
|
}
|
|
|
|
|
|
// 如果宽度和高度都大于0，则选择较小的缩放比例，以保持宽高比
|
|
|
if maxWidth > 0 && maxHeight > 0 {
|
|
|
scale := scaleWidth
|
|
|
if scaleHeight < scaleWidth {
|
|
|
scale = scaleHeight
|
|
|
}
|
|
|
|
|
|
// 计算缩略图尺寸
|
|
|
thumbnailWidth := int(float64(imgWidth) * scale)
|
|
|
thumbnailHeight := int(float64(imgHeight) * scale)
|
|
|
|
|
|
// 使用"image"库的Resample方法生成缩略图
|
|
|
thumbnail := image.NewRGBA(image.Rect(0, 0, thumbnailWidth, thumbnailHeight))
|
|
|
for y := 0; y < thumbnailHeight; y++ {
|
|
|
for x := 0; x < thumbnailWidth; x++ {
|
|
|
srcX := int(float64(x) / scale)
|
|
|
srcY := int(float64(y) / scale)
|
|
|
thumbnail.Set(x, y, img.At(srcX, srcY))
|
|
|
}
|
|
|
}
|
|
|
|
|
|
return thumbnail
|
|
|
}
|
|
|
|
|
|
// 如果只指定了宽度或高度，则根据最大不超过的规则生成缩略图
|
|
|
if maxWidth > 0 {
|
|
|
thumbnailWidth := maxWidth
|
|
|
thumbnailHeight := int(float64(imgHeight) * scaleWidth)
|
|
|
|
|
|
// 使用"image"库的Resample方法生成缩略图
|
|
|
thumbnail := image.NewRGBA(image.Rect(0, 0, thumbnailWidth, thumbnailHeight))
|
|
|
for y := 0; y < thumbnailHeight; y++ {
|
|
|
for x := 0; x < thumbnailWidth; x++ {
|
|
|
srcX := int(float64(x) / scaleWidth)
|
|
|
srcY := int(float64(y) / scaleWidth)
|
|
|
thumbnail.Set(x, y, img.At(srcX, srcY))
|
|
|
}
|
|
|
}
|
|
|
|
|
|
return thumbnail
|
|
|
}
|
|
|
|
|
|
if maxHeight > 0 {
|
|
|
thumbnailWidth := int(float64(imgWidth) * scaleHeight)
|
|
|
thumbnailHeight := maxHeight
|
|
|
|
|
|
// 使用"image"库的Resample方法生成缩略图
|
|
|
thumbnail := image.NewRGBA(image.Rect(0, 0, thumbnailWidth, thumbnailHeight))
|
|
|
for y := 0; y < thumbnailHeight; y++ {
|
|
|
for x := 0; x < thumbnailWidth; x++ {
|
|
|
srcX := int(float64(x) / scaleHeight)
|
|
|
srcY := int(float64(y) / scaleHeight)
|
|
|
thumbnail.Set(x, y, img.At(srcX, srcY))
|
|
|
}
|
|
|
}
|
|
|
|
|
|
return thumbnail
|
|
|
}
|
|
|
|
|
|
// 默认情况下，返回原始图片
|
|
|
return img
|
|
|
}
|
