first commit

clientsdk/imagetool.go

@@ -0,0 +1,106 @@
+package clientsdk
+
+import (
+	"bytes"
+	"github.com/lunny/log"
+	"image"
+	"image/gif"
+	"image/jpeg"
+	"image/png"
+	"net/http"
+
+	"github.com/nfnt/resize"
+	"xiawan/wx/clientsdk/baseinfo"
+)
+
+// CreateThumbImage 生成缩略图
+func CreateThumbImage(fileData []byte) *baseinfo.ThumbItem {
+	filetype := http.DetectContentType(fileData)
+	if filetype == "image/png" {
+		return CreatePngThumbImage(fileData)
+	}
+
+	if filetype == "image/jpeg" {
+		return CreateJpegThumbImage(fileData)
+	}
+
+	return nil
+}
+
+// CreateJpegThumbImage 创建JPEG图片的缩略图
+func CreateJpegThumbImage(srcImage []byte) *baseinfo.ThumbItem {
+	// 获取图片数据
+	srcImg, _ := jpeg.Decode(bytes.NewBuffer(srcImage))
+
+	// 缩略图宽/高设置成 120
+	width := uint(0)
+	height := uint(120)
+	if srcImg.Bounds().Dx() > srcImg.Bounds().Dy() {
+		width = 120
+		height = 0
+	}
+
+	// 生产缩略图
+	thumbImage := resize.Resize(width, height, srcImg, resize.Lanczos3)
+	emptyBuff := bytes.NewBuffer(nil)
+	// write new image to file
+	jpeg.Encode(emptyBuff, thumbImage, nil)
+
+	retThumbItem := &baseinfo.ThumbItem{}
+	retThumbItem.Data = emptyBuff.Bytes()
+	retThumbItem.Width = int32(thumbImage.Bounds().Dx())
+	retThumbItem.Height = int32(thumbImage.Bounds().Dy())
+
+	return retThumbItem
+}
+
+// CreatePngThumbImage 创建png图片的缩略图
+func CreatePngThumbImage(srcImage []byte) *baseinfo.ThumbItem {
+	// 获取图片数据
+	srcImg, _ := png.Decode(bytes.NewBuffer(srcImage))
+
+	// 缩略图宽/高设置成 120
+	width := uint(0)
+	height := uint(120)
+	if srcImg.Bounds().Dx() > srcImg.Bounds().Dy() {
+		width = 120
+		height = 0
+	}
+
+	// 生产缩略图
+	thumbImage := resize.Resize(width, height, srcImg, resize.Lanczos3)
+	emptyBuff := bytes.NewBuffer(nil)
+	// write new image to file
+	png.Encode(emptyBuff, thumbImage)
+
+	// 返回数据
+	retThumbItem := &baseinfo.ThumbItem{}
+	retThumbItem.Data = emptyBuff.Bytes()
+	retThumbItem.Width = int32(thumbImage.Bounds().Dx())
+	retThumbItem.Height = int32(thumbImage.Bounds().Dy())
+
+	return retThumbItem
+}
+
+// GetImageBounds 获取图片数据的宽高
+func GetImageBounds(fileData []byte) (uint32, uint32) {
+	if fileData == nil || len(fileData) <= 0 {
+		log.Error("获取图片数据的宽高error!")
+		return uint32(400), uint32(500)
+	}
+	filetype := http.DetectContentType(fileData)
+	var srcImg image.Image
+	if filetype == "image/png" {
+		srcImg, _ = png.Decode(bytes.NewBuffer(fileData))
+	}
+
+	if filetype == "image/jpeg" {
+		srcImg, _ = jpeg.Decode(bytes.NewBuffer(fileData))
+	}
+
+	if filetype == "image/gif" {
+		srcImg, _ = gif.Decode(bytes.NewBuffer(fileData))
+	}
+
+	return uint32(srcImg.Bounds().Dx()), uint32(srcImg.Bounds().Dy())
+}