UPC and EAN bar codes

　　Bar code is divided into one-dimensional bar code and two-dimensional bar code, of which there are more than one hundred kinds of one-dimensional bar code, in terms of color can be color bar code and black and white bar code. As the bar code can be read through the color contrast between the bar and the empty space, in general, the color can be used as long as it can meet the requirement of contrast (PCS value). Usually use light color for empty color, such as white, orange, yellow, etc., use dark color for bar, such as black, dark green, dark brown, etc. The most common combination is black stripes and white space. According to the practical experience of bar code detection, red, gold and light yellow should not be used as bar colors, and transparent and gold should not be used as empty colors.

　　The difference between EAN barcode and UPC barcode is as follows:

　　1. Different scope of use. EAN bar code is a kind of bar code customized by the International Article Coding Association, which has been distributed in more than 90 countries and regions around the world. UPC bar code is mainly used in the United States and Canada. UPC is a bar code customized by the Uniform Code Commission of the United States.

　　2. Different compilation subjects. EAN bar code is a bar code developed by the International Article Coding Association, and UPC bar code is a bar code developed by the United States uniform Code Commission.

　　3. Different standard codes. EAN bar code symbol has standard edition and shortened edition of two kinds, standard edition is composed of 13 digits, shortened version is composed of 8 digits. The UPC standard code is composed of 12 digits, and the UPC bar code is also available in standard edition and shortened edition. The standard edition is composed of 12 digits, and the shortened edition is composed of 8 digits, which is one less than the EAN bar code of the standard edition and the shortened edition is the same.