NOTE: Make a Reference to Adobe Acrobat X.x Type Library
NOTE2: This is untested code since you need Acrobat Pro (AP) to automate Acrobat (or so I have read) and I don't have it.
If you have AP the following code should get you close to what you need.
It is possible that AP will name their objects a bit differently.
Option Explicit '<<< first line of module/form
' Set Reference to Adobe Acrobat X.x Type Library
Private Sub Command1_Click()
Dim MyAcro As New AcroApp
Dim MyPDF As New AcroPDDoc
Dim MyPage As AcroPDPage
Dim MyPt As Acrobat.AcroPoint
Dim MyRect As AcroRect
Dim MyData As DataObject
Dim strPathString As String
Dim MyPath As String
Dim SaveToPath As String
MyPath = "C:\APath\AFile.PDF"
mysavepath = "C:\MyPDFImagesPath"
' open the PDF
Set MyPage = MyPDF.AcquirePage(0)
' Convert Point to Twips for document
Set MyPt = New AcroPoint
'Define the rectangle that contains the PDF form
Set MyRect = New Acrobat.AcroRect
MyRect.Top = 0
MyRect.Left = 0
MyRect.Right = MyPt.x
MyRect.bottom = MyPt.y
' Copy the PDF image to the clip board
Call MyPage.CopyToClipboard(MyRect, MyRect.Left, MyRect.Top, 100)
' Capture image from clip board to data object
Set MyData = Clipboard.GetData(vbCFBitmap)
'Save the data object
SavePicture MyData, mysavepath
' Clean up
Set MyAcro = Nothing
Set MyPDF = Nothing
Set MyPage = Nothing
Set MyPt = Nothing
Set MyRect = Nothing
Set MyData = Nothing
Yes, PDF files can be converted to images! But it's not a native capability of VB6. You'll need to obtain a third-party component to perform the conversion.
The alternative is to write your own software to decode and render PDF documents, not a trivial task. If you're prepared to spend the time and effort though, Adobe's PDF reference might be a good place to start: http://www.adobe.com/devnet/pdf/pdf_reference.html
The example below demonstrates how to render documents using VB6 with a component (the easy option):
Set doc = CreateObject("ABCpdf9.Doc")
For i = 1 To doc.PageCount
doc.PageNumber = i
doc.Rendering.Save "example-" & i & ".png"
The code makes use of ABCpdf.NET Professional, although any component which provides a COM interface and similar features should work just as well. Support for VB6 can be found in the legacy documentation for ABCpdf ASP, usually included with the installation package.
Like AffineMesh94464 mentioned, there are third-party components that are quite capable in regards to reading PDFs and saving images. Unfortunately, most of them stopped supporting vb6 in their new versions, but I found a post that suggests at least one of them still does: http://support.leadtools.com/CS/forums/41356/ShowPost.aspx
I haven't used VB6 recently so I did not actually try this post and it does talk about loading an image, but they claim the same code can be used for PDF files. Hope this helps.