Commentary about a comment

image_wrapper.ts function InImageWithBorder, line 52

            // "TODO: this doesn't make much sense to me, why does it go negative?  Tests are not affected by
            // returning false, but the whole code_128 reader blows up when i throw [exception] on negative imgRef [line]."
            // assertNumberPositive(imgRef.x);
           // assertNumberPositive(imgRef.y);

When extending the line in both directions, it is quite common for the extension to exceed the image boundary.

The border extension I add is typically 10% of the current line length. If the line starts at {10,y} and goes to {310,y}, then the length with be 300. 10% would result in 30. 30 from 10 is -20.

[TonyKhorouzan]

I like the idea.

I will keep my eye out for where Quagga is getting the edge off a bit. If I find a good example, I will research why. Perhaps we can prevent the inaccurate edge issue and not need to apply a white border. I am less concerned with decoding a barcode than identifying its precise location.

[ericblade]

I do a lot of retail product scanning, and I see it a lot when there’s other graphics/text close to barcodes, as often seen on small retail items. Usually holding my finger near one edge of the barcode allows for a scan to work. it would be nice if we could manage to get some of these instances more accurate. There are plenty of failing testcases in the repo that i suspect would work with small amounts of pre-processing or maybe even just using different patch/resolution settings. But it’s not something I’ve had time to dig into, and my background/experience is in much different areas. 😃