代码实现
步骤1：下载imagick
步骤2：go实现代码如下
package main import ( "os" "strconv" "gopkg.in/gographics/imagick.v2/imagick" ) func main() { ConvertPdfToImage("test.pdf", 800, 1212, 200, 85) } //ConvertPdfToImage 转换pdf为图片格式 //@resolution:扫描精度 //@CompressionQuality:图片质量: 1~100 func ConvertPdfToImage(bookname string, pageWidth uint, pageHeight uint, resolution float64, compressionQuality uint) (err error) { imagick.Initialize() defer imagick.Terminate() mw := imagick.NewMagickWand() //defer mw.Clear() defer mw.Destroy() if err := mw.SetResolution(resolution, resolution); err != nil { println("扫描精度设置失败") return err } if err := mw.ReadImage(bookname); err != nil { println("文件读取失败") return err } var pages = int(mw.GetNumberImages()) println("页数:", pages) //裁剪会使页数增加 addPages := 0 path := "" for i := 0; i < pages; i++ { mw.SetIteratorIndex(i) // This being the page offset //压平图像，去掉alpha通道，防止JPG中的alpha变黑,用在ReadImage之后 if err := mw.SetImageAlphaChannel(imagick.ALPHA_CHANNEL_FLATTEN); err != nil { println("图片") return err } mw.SetImageFormat("jpg") mw.SetImageCompression(imagick.COMPRESSION_JPEG) mw.SetImageCompressionQuality(compressionQuality) //如果width>height ,就裁剪成两张 pWidth := mw.GetImageWidth() pHeight := mw.GetImageHeight() //需要裁剪 if pWidth > pHeight { //mw.ResizeImage(pageWidth*2, pageHeight, imagick.FILTER_UNDEFINED, 1.0) mw.ThumbnailImage(pageWidth*2, pageHeight) tempImage := mw.GetImageFromMagickWand() leftMw := imagick.NewMagickWandFromImage(tempImage) //由于返回的是指针,需要提前初始化,不然写完左半业tempImage就变了 //左半页 mw.CropImage(pageWidth, pageHeight, 0, 0) path = "./book/page" + strconv.Itoa(i+addPages) + ".jpg" mw.WriteImage(path) //右半页 leftMw.SetImageFormat("jpg") leftMw.SetImageCompression(imagick.COMPRESSION_JPEG) leftMw.SetImageCompressionQuality(compressionQuality) leftMw.CropImage(pageWidth, pageHeight, int(pageWidth), 0) addPages++ path = "./book/page" + strconv.Itoa(i+addPages) + ".jpg" leftMw.WriteImage(path) leftMw.Destroy() } else { mw.ThumbnailImage(pageWidth, pageHeight) path = "./book/page" + strconv.Itoa(i+addPages) + ".jpg" mw.WriteImage(path) } } println("转换完毕!") os.Exit(0) //模拟退出程序,删掉! return nil }
三、问题解决
在运行过程中报错如下：
问题一：../gopkg.in/gographics/imagick.v2/imagick/drawing_wand.go:39: undefined: runtime.KeepAlive
解决：go版本过低导致
问题二：go build gopkg.in/gographics/imagick.v2/imagick: invalid flag in pkg-config --cflags: -fopenmp
解决：go版本原因。
问题三：/tmp/go-build695941684/command-line-arguments/_obj/exe/pdfconvert: error while loading shared libraries: libMagickWand-6.Q16.so.5: cannot open shared object file: No such file or directory
解决：进入目录/user/local/lib中，运行ldconfig /user/local/lib。即解决。