Coarse Search For Barcodes In A Large Images

There are a few decent python modules that are capable of reading barcodes in images. They work reliably if the barcode is large enough in the image. They do not provide any kind of ability for searching a large image for a small barcode (that I know of). I require a module that guesses coordinates until barcode(s) are extracted from an image.

The first part of this project is some scaffolding. The project should have an interface between a search algorithm and a scaffold that tries search results and parses the results of trying those search results. The project is then divided into two parts, on either side of that interface. This interface is meant to allow creating pluggable components by completely decoupling the barcode scanning package from the search algorithm.

The motivation to solve this problem comes from extending a document management system. The source images are going to be classes of forms that have barcodes always in the same spot. I see the project as having a significant potential to be useful to lots of people...if done well. I think the most important part is sticking to this interface.

Since the first use of this project will be to scan a certain well-defined form, it will start with a search module that is specifically designed to extract a barcode from that form. It's important to decouple any implementation details of this "dumb" search module from the as-yet undefined abstract search API.

This module will be hard-coded to find one particular barcode most likely on the first guess of a box coordinate. Stated like this, the first definition of the project's API comes into light. We are given a BCS (box coordinate slice) to try, and parse the results. The parser will black box the actual module that performs the barcode analysis. I think a certain constraint needs to be introduced...that a BCS is meant only to contain a single barcode. The user should be easily able to define a regular expression that checks the validity of the barcode. This would be for a convenience layer, that could potentially be an API to a set of document classes. A document class would define a list of barcodes and corresponding optimized search functions. This could be the beginning of a third component of the system, or that be more integrated with the document management system than the actual barcode scanning system.

The creation of the hard-coded search for a particular form is important. Firstly, our goal should be to get something functional as soon as possible. In order to iterate towards this goal as soon as possible, a requirement will be the ability to benchmark the search on a reasonable test data set from the beginning.

The process of creating a hard-coded search module will start with a guess for the BCS that works on the test data set. The document has a pretty gigantic barcode on it, for now, with a goal in mind to shrink it. A BCS of the quadrant of the document that contains the barcode will be the first guess, and I'm not going to change that guess until the project can successfully analyze the effectiveness of that guess, and adheres to the design laid out in this first document.