Zxing is more than capable recognising PDF417 barcodes.
You might get more luck with the BarcodeReader.TryHarder
settings which will use more CPU cycles.
The problem is not with Zxing is more likely having trouble with the image quality due to the size of the image. Ie PDF417 requires at least one of those funny little lines on the sides of your image to be identifiable, otherwise it will fail. from looking at your image it looks like either the paper is very bad quality, or your image is very bad quality.
However, once again, i think this is your optics not Zxing. i just tested this with my phone and xzing, and i couldn't get that image to work. however i use this app in production all over our warehouse with pdf417 of all shapes and sizes and it works flawlessly