How to detect barcodes when they are arranged horizontally and vertically at the same time?

[Wjat777]

Hi,

Firstly, sorry to post this as an issue (I know this is not a bug), but I don't found a official community forum for ZXing integration.

I have this 3 situations:
BarCode1.jpg : 2 Barcodes code 128 and 2 Barcodes 39=>All codes are read correctly

CODE_39[39;210;327;210] : ABC-1234
CODE_128[33;105;319;105] : ABC-abc-1234
CODE_128[424;52;600;52] : 123456787
CODE_39[404;213;628;213] : 123456

BarCode2.jpg : 2 Barcodes code 128 (1 horizontal and 1 vertical) and 3 Barcodes 39(1 horizontal and 1 vertical)=>Only horizontal codes are read correctly

CODE_39[39;210;327;210] : ABC-1234
CODE_128[33;105;319;105] : ABC-abc-1234

BarCode3.jpg : 2 Barcodes code 128 (1 horizontal and 1 vertical) and 2 Barcodes 39(2 horizontal and 1 vertical)=>Only horizontal codes are read correctly and the duplicate code was ignored.

CODE_39[39;267;327;267] : ABC-1234
CODE_128[33;133;319;133] : ABC-abc-1234

My code is very simple

private string ScanBarcode(Bitmap bitmap)
{
	Bitmap target;
	var reader = new ZXing.Windows.Compatibility.BarcodeReader()
	{
		AutoRotate = true,
		Options = new DecodingOptions
		{
			TryHarder = true,
			PureBarcode = false,
			ReturnCodabarStartEnd = true,
		}
	};
	Result[] result = reader.DecodeMultiple(bitmap);
	if (result==null) return "not found";
	string barcodeResult = "";
	foreach (var res in result)
	{
		barcodeResult += res.BarcodeFormat.ToString() +"[" +res.ResultPoints[0].X +";"+ res.ResultPoints[0].Y +";" +res.ResultPoints[1].X + ";" + res.ResultPoints[1].Y + "]" + " : " + res.Text + "\r\n";
	}
	return barcodeResult;
}

I'm using ZXing.Windows.Compatibility (0.16.13.0) and ZWing (0.16.10.0)

My questions are
1 - Exists an option to force read all barcodes regardless of orientation?
2 - Exists an option to force read all barcodes regardless of whether they are duplicated?

The case of duplication is weird but we have some forms where the same barcode is duplicated, I think, for redundancy reasons if the form is scratched out, but I would still like to get the position of both barcodes.

Thanks

[mxmissile]

You ever find a solution to this?

[Wjat777]

For vertical barcodes I need flip 90° the image and retry.

The problem with this apporche is that I won't always have vertical barcodes, so I think it's wasted processing.

As for the problem of having two equal bars, I didn't find an easy solution.

What was recommended to me was to CROP the image excluding the bars already found. As I won't always have the duplication of barcodes, I also found it a processing waste.

Ideally, I would like the method BarcodeReader() to bring all the found codes (in any position) and in the case of duplication, I decide whether to keep it or not.

[SanKumSan]

Hello @Wjat777
Are you still looking for a solution to find both types at one go ?

[Wjat777]

Hi @SanKumSan,

Yes, I don't found a solution in one step. But this is not a great problem. The main problem, I think, is the behaviour the library scans only 1 barcode if this one this duplicate in the page.

[SanKumSan]

Hello @Wjat777
If I understand correctly , let us say there is barcode1 two times at different locations and the Zxing reader finds barcode from only one location? and the second barcode with the same value/duplicate is not detected and decoded ?

I have not come across this behaviour. I can try to test this myself and a hint of reader and settings would be helpfull to reproduce this.

If you are intereseted in a solution to find all the barcodes on the given page using OpenCV, then let me know. I will try to help you (this solution has the chance to find both horizontal and vertical ones at one go or in separate steps)

[axxel]

In case this is still of interest a year later: https://www.nuget.org/packages/ZXingCpp can decode all of them just fine with no special treatment, except the 90° rotated 123456787. That one got corrupted during rotation.