My solution to the problem, I don't need barcodes, I just take a photo for each item when it is sold. Then I can apply AI technics to recognize and classify the photos. Then I would be able to know, say, how many pants, tops or skirts I sold each day.

Well, if you get that to work, you should be able to retire quite comfortably on the profits. More likely though, is that you won't ever get it even remotely as reliable as barcodes/rfid which are made to do just that and even then they're not 100% reliable.

As an example of an image recognition system: this link describes a traffic-sign recognition system. Note that traffic signs are designed to be easily differentiated. This thing will recognize 3 signs a second and has 98% "recognition rate" (which in my estimates is much worse than the usual barcode scanner at the super market)