초록 ▼

A system and method to binarize the bar code image in the presence of noise in order to render bar codes more detectable in the presence of noise. The method of this invention includes the steps of applying a gradient detecting filter to the bar code image, obtaining a filtered image, and then, adap

A system and method to binarize the bar code image in the presence of noise in order to render bar codes more detectable in the presence of noise. The method of this invention includes the steps of applying a gradient detecting filter to the bar code image, obtaining a filtered image, and then, adaptively binarizing the bar code image utilizing the corresponding filtered image to obtain an adaptive threshold. A system that implements the method is also described.

대표청구항 ▼

What is claimed is: 1. A method for decoding a bar code image in the presence of noise, the bar code image being a digitized image comprising pixels, each of said pixels having a corresponding digitized bar code image value, said method comprising the steps of: applying a gradient detecting filter

What is claimed is: 1. A method for decoding a bar code image in the presence of noise, the bar code image being a digitized image comprising pixels, each of said pixels having a corresponding digitized bar code image value, said method comprising the steps of: applying a gradient detecting filter to the digitized bar code image values; obtaining a filtered image comprising filtered image pixels, each of the filtered image pixels having a corresponding filtered image pixel value; adaptively binarizing the digitized bar code image value by utilizing said filtered image pixel value to obtain an adaptive threshold. 2. The method of claim 1 wherein the gradient detecting filter comprises a directional filter. 3. The method of claim 2 wherein the directional filter comprises a Sobel filter times a constant. 4. The method of claim 1 wherein the step of adaptively binarizing the digitized bar code image value further comprises the step of comparing the digitized bar code image value to the filtered image pixel value at each of said pixels. 5. A system for decoding a bar code image in the presence of noise, the bar code image being a digitized image comprising pixels, each of the pixels having a corresponding digitized bar code image value, said system comprising: means for applying a gradient detecting filter to the digitized bar code image, obtaining a filtered image comprised of filtered image pixels, each said filtered image pixels having a corresponding filtered image pixel value; means for adaptively binarizing the digitized bar code image utilizing the filtered image pixel value to obtain an adaptive threshold. 6. The system of claim 5 wherein the gradient detecting filter comprises a directional filter. 7. The system of claim 6 wherein the directional filter comprises a Sobel filter times a constant. 8. The system of claim 5 wherein the means for adaptively binarizing the digitized bar code image value further comprise means for comparing the digitized bar code image value to the filtered image pixel value at each pixel. 9. A computer program product comprising: a computer usable medium having computer readable code embodied therein for decoding a bar code image in the presence of noise, said image being a digitized image comprising pixels, each said pixel having a corresponding digitized bar code image value, said code causing a computer system to: apply a gradient detecting filter to the digitized bar code image; obtain a filtered image comprised of filtered image pixels, each said filtered image pixels having a corresponding filtered image pixel value; adaptively binarize the digitized bar code image utilizing the filtered image pixel value to obtain an adapuve threshold. 10. The computer program product of claim 9 where, in the computer readable code that causes a computer system to apply a gradient detecting filter to the digitized bar code image, the gradient detecting filter comprises a directional filter. 11. The computer program product of claim 10 where, in the computer readable code that causes a computer system to apply a directional filter to the digitized bar code image, the directional filter comprises a Sobel filter times a constant. 12. The computer program product of claim 9 where, in the computer readable code that causes a computer system to adaptively binarize the digitized bar code image, further causes the computer system to compare the digitized bar code image value to the filtered image pixel value at each pixel. 13. The computer program product of claim 9 where, in the computer readable code that causes a computer system to apply a gradient detecting filter to the digitized bar code image, the gradient detecting filter comprises a two dimensional gradient detecting filter. 14. A binarized bar code image obtained from a digitized bar code image, the digitized bar code image being a digitized image comprising pixels, each of said pixels having a corresponding digitized bar code image value, by: applying a gradient detecting filter to the digitized bar code image values; obtaining a filtered image comprising filtered image pixels, each of the filtered image pixels having a corresponding filtered image pixel value; adaptively binarizing the digitized bar code image value by utilizing said filtered image pixel value to obtain an adaptive threshold; whereby said binarized bar code image is easily decoded in the presence of noise. 15. The binarized bar code image of claim 13 wherein said gradient detecting filter comprises a directional filter. 16. The binarized bar code image of claim 14 wherein the gradient detecting filter comprises a Sobel filter times a constant. 17. The binarized bar code image of claim 14 wherein the step of adaptively binarizing the digitized bar code image value further comprises the step of comparing the digitized bar code image value to the filtered image pixel value at each of said pixels. 18. The binarized bar code image of claim 14 wherein said gradient detecting filter comprises a two dimensional gradient filter. 19. A method for decoding a bar code image in the presence of noise, the bar code image being a digitized image comprising pixels, each of said pixels having a corresponding digitized bar code image value, said method comprising the steps of: applying a two dimensional gradient detecting filter to the digitized bar code image values; obtaining a filtered image comprising filtered image pixels, each of the filtered image pixels having a corresponding filtered image pixel value; adaptively binarizing the digitized bar code image value by utilizing said filtered image pixel value to obtain an adaptive threshold. 20. The method of claim 19 wherein the two dimensional gradient detecting filter comprises a directional filter. 21. The method of claim 20 wherein the two dimensional directional filter comprises a Sobel filter times a constant. 22. The method of claim 19 wherein the step of adaptively binarizing the digitized bar code image value further comprises the step of comparing the digitized bar code image value to the filtered image pixel value at each of said pixels. 23. A system for decoding a bar code image in the presence of noise, the bar code image being a digitized image comprising pixels, each of the pixels having a corresponding digitized bar code image value, said system comprising: means for applying a two dimensional gradient detecting filter to the digitized bar code image, obtaining a filtered image comprised of filtered image pixels, each said filtered image pixels having a corresponding filtered image pixel value; means for adaptively binarizing the digitized bar code image utilizing the filtered image pixel value to obtain an adaptive threshold. 24. The system of claim 23 wherein the two dimensional gradient detecting filter comprises a directional filter. 25. The system of claim 24 wherein the directional filter comprises a Sobel filter times a constant. 26. The system of claim 23 wherein the means for adaptively binarizing the digitized bar code image value further comprise means for comparing the digitized bar code image value to the filtered image pixel value at each pixel.