Merx: Thanks, I'll take a look at that
The PDF's I'm trying to read are pretty plain vanilla, so I doubt that I'll run into out-of-order issues... But thanks for the warning.
The example above extractPDFText.aspx assumes one kind of filter/encoding. ASCII85 encoding is also potentially used. PDF files are not required to store data in page order which means this code extracts text sequentially in the file, but it may be out of logical page order. If the file has been linearized or incrementally updated, then you may also find "legacy" objects that aren't even used by the file anymore.
The PDF's I'm trying to read are pretty plain vanilla, so I doubt that I'll run into out-of-order issues... But thanks for the warning.