Determining barcode locations in documents
A method of producing barcode locations within a document comprising providing an original digital image of the document; using a processor for producing a normalized image from the original digital image; producing a gradient image from the normalized image; producing a plurality of bounding boxes from the gradient image; and producing bounding box test results by testing each bounding box for the presence of a barcode; and producing barcode locations within the document from the bounding box test results.
1. A method of producing barcode locations within a document comprising:
(a) providing an original digital image of the document;
(b) using a processor for:
(i) producing a normalized image from the original digital image, including producing a grayscale image from the original digital image and producing a full-scale histogram stretched image from the grayscale image;
(ii) producing a gradient image from the normalized image;
(iii) producing a plurality of bounding boxes from the gradient image; and
(iv) producing bounding box test results by testing each bounding box for the presence of a barcode; and
(c) producing barcode locations within the document from the bounding box test results.
2. The method of claim 1 further including using histogram penetration to produce the full-scale histogram stretched image.
3. The method of claim 1 wherein producing a gradient image includes producing a downsampled image from the normalized image and a directional gradient image from the downsampled image.
4. The method of claim 3 further including using histogram stretching and thresholding on the directional gradient image to produce the gradient image.
5. The method of claim 1 wherein producing a plurality of bounding boxes includes finding minimum bounding boxes around each feature in the gradient image.
6. The method of claim 1 wherein producing bounding box test results includes, for each bounding box region within the normalized image, testing for the presence of a minimum barcode pixel value and a maximum barcode pixel value.
7. The method of claim 1 wherein producing bounding box test results includes, for each bounding box region within the gradient image, computing a barcode black pixel ratio and comparing it to a barcode black pixel ratio threshold value.
8. A method of producing improved barcode regions within a document comprising:
(a) providing an original digital image of the document;
(b) using a processor for:
(i) producing a normalized image from the original digital image, including producing a grayscale image from the original digital image and producing a full-scale histogram stretched image from the grayscale image;
(ii) producing a gradient image from the normalized image;
(iii) producing a plurality of bounding boxes from the gradient image; and
(iv) producing bounding box test results by testing each bounding box for the presence of a barcode;
(c) producing barcode locations within the document from the bounding box test results;
(d) producing barcode regions within the document from the barcode locations; and
(e) producing improved barcode regions from the barcode regions.
9. The method of claim 8 wherein producing improved barcode regions further includes processing the barcode regions differently from the rest of the document.
10. The method of claim 9 further including not processing the barcode regions as the document is processed.
11. A method of producing barcode locations within a document comprising:
(a) providing an original digital image of the document;
(b) using a processor for:
(i) producing a normalized image from the original digital image;
(ii) producing a gradient image from the normalized image, including producing a downsampled image from the normalized image and a directional gradient image from the downsampled image;
(iii) producing a plurality of bounding boxes from the gradient image; and
(iv) producing bounding box test results by testing each bounding box for the presence of a barcode; and
(c) producing barcode locations within the document from the bounding box test results.
12. A method of producing barcode locations within a document comprising:
(a) providing an original digital image of the document;
(b) using a processor for:
(i) producing a normalized image from the original digital image;
(ii) producing a gradient image from the normalized image;
(iii) producing a plurality of bounding boxes from the gradient image; and
(iv) producing bounding box test results by testing each bounding box for the presence of a barcode, including, for each bounding box region within the normalized image, testing for the presence of a minimum barcode pixel value and a maximum barcode pixel value; and
(c) producing barcode locations within the document from the bounding box test results.
13. A method of producing barcode locations within a document comprising:
(a) providing an original digital image of the document;
(b) using a processor for:
(i) producing a normalized image from the original digital image;
(ii) producing a gradient image from the normalized image;
(iii) producing a plurality of bounding boxes from the gradient image; and
(iv) producing bounding box test results by testing each bounding box for the presence of a barcode, including, for each bounding box region within the gradient image, computing a barcode black pixel ratio and comparing it to a barcode black pixel ratio threshold value; and
(c) producing barcode locations within the document from the bounding box test results.