Use JavaScript to count the number of words on each page, this will count visible and invisible words. No words inidicates a non-searchable PDF.
From the Acrobat JS API Reference:
// count the number of words in a document var cnt=0; for (var p = 0; p < this.numPages; p++) cnt += getPageNumWords(p); console.println("There are " + cnt + " words on this page.");
From the Acrobat JS API Reference:
// count the number of words in a document
var cnt=0;
for (var p = 0; p < this.numPages; p++)
cnt += getPageNumWords(p);
console.println("There are " + cnt + " words on this page.");
George Kaiser