How to specify scan area to read barcode

You can limit the barcode decoding area using the scanArea property. You can set this in the profiles parameter.

"profiles": "{'scanArea': 'TopHalf'}"

Or you can narrow the scanArea more by setting the custom area. Here's an example:

"profiles": "{ 'ScanArea': 'Custom', 'CustomAreaLeft': 0, 'CustomAreaTop': 640, 'CustomAreaWidth': 595, 'CustomAreaHeight': 200 }"

Coordinates are in pixels. If decoding from PDF, to get the page size in pixels, you should calculate from the size in Points according to the property PDFRenderingResolution. E.g.:

widthInPixels = widthInPoints / 72 * PDFRenderingResolution