完善功能

graphics/copy.go

@@ -0,0 +1,49 @@
+package graphics
+
+import (
+	"image"
+	"os"
+	"errors"
+
+	"github.com/nfnt/resize"
+)
+
+func ImageCopy(src image.Image,x, y ,w, h int) (image.Image,error)  {
+
+	var subImg image.Image
+
+	if rgbImg,ok := src.(*image.YCbCr); ok {
+		subImg = rgbImg.SubImage(image.Rect(x, y, x+w, y+h)).(*image.YCbCr) //图片裁剪x0 y0 x1 y1
+	}else if rgbImg,ok := src.(*image.RGBA); ok {
+		subImg = rgbImg.SubImage(image.Rect(x, y, x+w, y+h)).(*image.YCbCr) //图片裁剪x0 y0 x1 y1
+	}else if rgbImg,ok := src.(*image.NRGBA); ok {
+		subImg = rgbImg.SubImage(image.Rect(x, y, x+w, y+h)).(*image.YCbCr) //图片裁剪x0 y0 x1 y1
+	} else {
+
+		return subImg,errors.New("图片解码失败")
+	}
+
+	return subImg,nil
+}
+
+func ImageCopyFromFile(p string,x, y ,w, h int) (image.Image,error) {
+	var src image.Image
+
+	file, err := os.Open(p)
+	if err != nil {
+		return src, err
+	}
+	defer file.Close()
+	src, _, err = image.Decode(file)
+
+	return ImageCopy(src, x, y, w, h)
+}
+
+func ImageResize(src image.Image,w,h int) (image.Image) {
+	return resize.Resize(uint(w), uint(h), src, resize.Lanczos3)
+}
+func ImageResizeSaveFile(src image.Image,width,height int,p string) error {
+	dst := resize.Resize(uint(width), uint(height), src, resize.Lanczos3)
+
+	return SaveImage(p,dst)
+}

graphics/file.go

@@ -0,0 +1,32 @@
+package graphics
+
+import (
+	"image"
+	"os"
+	"path/filepath"
+	"strings"
+	"image/jpeg"
+	"image/png"
+	"image/gif"
+)
+// 将图片保存到指定的路径
+func SaveImage(p string, src image.Image) error {
+
+	f, err := os.OpenFile( p, os.O_SYNC | os.O_RDWR | os.O_CREATE, 0666)
+
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	ext := filepath.Ext(p)
+
+	if strings.EqualFold(ext, ".jpg") || strings.EqualFold(ext, ".jpeg") {
+
+		err = jpeg.Encode(f, src, &jpeg.Options{Quality : 100 })
+	} else if strings.EqualFold(ext, ".png") {
+		err = png.Encode(f, src)
+	} else if strings.EqualFold(ext, ".gif") {
+		err = gif.Encode(f, src, &gif.Options{NumColors : 256})
+	}
+	return err
+}