Loaded-Page Barcode Decoding
THotPDF.DecodeLoadedPageBarcodes renders one loaded page or a page-space region and lends the resulting 24-bit bitmap to an application-selected IHPDFBarcodeDecoder
The default 144 DPI path uses progressive display-list rendering, caps raster pixels and peak working bytes, and checks cancellation between render slices, rotation attempts, decoder calls, and result validation
Rotation and coordinates
bdrpFallback first decodes the original raster and only allocates 90, 180, and 270 degree copies when no valid result has been accepted, avoiding four decoder calls on the common path
The decoder reports pixel bounds and clockwise orientation relative to the borrowed attempt bitmap
HotPDF reverses the attempt rotation and the page render matrix, returning an axis-aligned rectangle and counter-clockwise orientation in PDF page user space, including pages whose /Rotate entry is non-zero
Validation and deduplication
Every result is checked for finite confidence, orientation, geometry, valid Unicode, and configured text and raw-byte limits
When all rotations are requested, matching symbology, payload, and overlapping page bounds are deduplicated by intersection-over-union and the highest-confidence candidate is retained
The operation never modifies the loaded object graph and publishes no partial result array after render, decoder, budget, or cancellation failure