IHPDFFaceDetector Interface
function Detect(
const Request: THPDFFaceDetectionRequest;
out Results: THPDFFaceDetectorResults;
out Diagnostic: AnsiString): boolean;
Detect receives a bounded 24-bit rendered bitmap and returns top-left-origin pixel rectangles together with confidence values
The detector executes synchronously, must honour MaxResults and cancellation, and must not retain Bitmap after the call
HotPDF validates every rectangle and reverses page rotation and device scaling into PDF page user space