最近在研究pdf to img 看了网上一些资料没找到个实用的，用第三方程序怕有问题，于是就想利用Adobe Acrobat 7.0 Professional 自带的导出图片的功能，资料忒少啊。找了半天，下面这个比较有用。不过说句实在话，我只是用别人的东西，没自己原创的东西。

原文：http://fidodido2010.spaces.live.com/blog/cns!42DBF9483C966838!129.entry

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PDF转换成其他格式的COM解决方案
需求起源:

最近图片格式之间相互转换做得比较多,以往的转换LEADTOOLS R13肯定能搞定,却发现有一部分PDF用LEADTOOLS打不开,只好又把Acrobat捡起来了.

研究了半天,总算找到个办法,却被AcroExch.PDDoc的一个接口GetJSObject()难住了.照理说,这个接口返回的是一个JavaScript对象,可是C++下却没有相应的类型说明,只能用IDispatch,调用机制及IType完全搞不清楚,所有的能G到的相关内容几乎全是VB的，只有一个可怜的老外问过"Using GetJSObject() in C++"的问题，而且答案还是"since it involves low level COM API's to get directly to the IDispatch for the object.".

正想以头抢地,或者考虑整个工程迁移到VB下去,忽然想起,何不用VB做个专门调用这个接口的COM,在C++下面调用？

说干就干

用VB6编写Acrobat COM:

建立一个VB6的ActiveX Dll工程,工程名称改为MPDF2SIMG(Multi-page PDF to Single-page Image),模块名改为Converter,添加引用"Adobe Acrobat 7.0 Type Library".模块的全部代码如下：

Option Explicit On

Dim oApp As Acrobat.CAcroApp
Dim oMultiPageDoc As Acrobat.CAcroPDDoc
Dim oSinglePageDoc As Acrobat.CAcroPDDoc
Dim JSO As Object

Private Sub Class_Initialize()
    oApp = CreateObject("AcroExch.App")
    oMultiPageDoc = CreateObject("AcroExch.PDDoc")
End Sub

Public Function ConvertPDF(ByVal SourcePDF As String, _
    ByVal TargetFolder As String, _
    ByVal TargetFormat As String, _
    ByVal StartImgNumber As Integer) As Integer

Dim iNumbers As Integer
    Dim i As Integer
    Dim OutPath As String
    Dim OutFile As String

OutPath = TargetFolder
    If Right(OutPath, 1) <> "\" Then OutPath = OutPath & "\"

On Error GoTo err1

oMultiPageDoc.Open(SourcePDF)

iNumbers = oMultiPageDoc.GetNumPages

For i = 0 To iNumbers - 1
        oSinglePageDoc = CreateObject("AcroExch.PDDoc")
        oSinglePageDoc.Create()
        oSinglePageDoc.InsertPages(-1, oMultiPageDoc, i, 1, 0)
        JSO = oSinglePageDoc.GetJSObject
        OutFile = OutPath & Format(i + StartImgNumber, "00000000") & _
            ".tif"
        JSO.SaveAs(OutFile, "com.adobe.acrobat." & TargetFormat)
        JSO = Nothing
        oSinglePageDoc = Nothing
    Next

oMultiPageDoc.Close()
    oApp.CloseAllDocs()
    ConvertPDF = iNumbers
    Exit Function
err1:
    ConvertPDF = -1
End Function

Private Sub Class_Terminate()
    oMultiPageDoc = Nothing
    oSinglePageDoc = Nothing
End Sub然后编译成DLL.  使用这个DLL的方法:1.在计算机上运行regsvr32 mpdf2simg.dll注册这个DLL.2.使用这个DLL的C++程序里导入该COM的类型库，代码如下：#import "E:\project\Converter\mpdf2simg.dll"
using namespace MPDF2SIMG;3.定义COM型变量并建立实例，代码如下：

_ConverterPtr    pConverter;
HRESULT hr = pConverter.CreateInstance(_T("MPDF2SIMG.Converter"));
if(!FAILED(hr))
{
    //do something if failed.
    ...
}4.调用该COM的接口

int nConv = pConverter->ConvertPDF(
    CString(_T("xxxxxx\\source.pdf")).AllocSysString(),
    CString(_T("d:\\TargetPath")).AllocSysString(),
    CString(_T("tiff")).AllocSysString(),
    nStart);该调用会将指定的SoucePDF转至TargetPath下连续的单页TIFF文件,文件名为8位数字编号形式,编号起始由nStart指定.

调用成功返回转换的页数，失败返回-1

其他支持的格式:

值  可用扩展名 
"com.adobe.acrobat.eps"  eps 
"com.adobe.acrobat.html-3-20"  html, htm 
"com.adobe.acrobat.html-4-01-css-1-00"  html, htm 
"com.adobe.acrobat.jpeg"  jpeg, jpg, jpe 
"com.adobe.acrobat.jp2k"  jpf, jpx, jp2, j2k, j2c,jpc 
"com.adobe.acrobat.doc"  doc 
"com.adobe.acrobat.png"  png 
"com.adobe.acrobat.ps"  ps 
"com.adobe.acrobat.rtf"  rtf 
"com.adobe.acrobat.accesstext"  txt 
"com.adobe.acrobat.plain-text"  txt 
"com.adobe.acrobat.tiff"  tiff, tif 
"com.adobe.acrobat.xml-1-00"  xml

已知问题和BUG:

如果C++程序使用多字节字符集编译, TargetPath中含有中文字符会导致无法正常转换,ConvertPDF调用会导致弹出"无法保存文件"的Acrobat对话框, 点确定ConvertPDF会返回-1.Unicode字符集未做测试.

补充说明:

使用Acrobat COM, 应在计算机上部署Adobe Acrobat (Not Reader).

-----------------------------------我自己的就简单了用-Adobe professinal-------------------------------

　　　Dim gApp As Acrobat.CAcroApp
        Dim oMultiPageDoc As Acrobat.CAcroPDDoc
        Dim oSinglePageDoc As Acrobat.CAcroPDDoc
        Dim iNumbers As Integer
        Dim StartImgNumber As Integer
        Dim OutFile As String
        Dim i As Integer
        Dim jso As Object
        gApp = CreateObject("AcroExch.App")
        oMultiPageDoc = CreateObject("AcroExch.PDDoc")

'pdf和生成的文件要在同一个文件夹下
        If oMultiPageDoc.Open("F:\test.pdf") Then

iNumbers = oMultiPageDoc.GetNumPages

For i = 0 To iNumbers - 1
                oSinglePageDoc = CreateObject("AcroExch.PDDoc")
                oSinglePageDoc.Create()
                oSinglePageDoc.InsertPages(-1, oMultiPageDoc, i, 1, 0)
                jso = oSinglePageDoc.GetJSObject
                OutFile = Format(i + StartImgNumber, "00000000") & ".png"
                jso.SaveAs("F:\" & OutFile, "com.adobe.acrobat.png")
                jso = Nothing
                oSinglePageDoc = Nothing
            Next

End If

-----附送一个用GhostScriptView的----------------

C:\Program Files\gs\gs8.61\bin\gswin32c.exe -dSAFER -dBATCH -dNOPAUSE -r300 -sDEVICE=png16m -dGraphicsAlphaBits=4

-sOutputFile="F:\test.pdf"  "F:\test\"