A single 1 would be the thinnest line in the bar code. For instance, encoding the ASCII character "0" can be viewed as 10011101100, where a sequence of 1's is a bar and a sequence of 0's is a space. Each bar or space is 1, 2, 3 or 4 units wide, the sum of the widths of bars must be even (4, 6 or 8 units), the sum of the widths of the spaces must be odd (3, 5 or 7 units), and total 11 units per symbol. It is mandatory at the left and right side of the barcode.Įach symbol in the barcode is composed of three bars and three spaces. The minimum width of the quiet zone to the left and right of the Code 128 is 10x, where x is the minimum width of a module. 128C (Code Set C) – 00–99 (encodes two digits with a single code point) and FNC1.128B (Code Set B) – ASCII characters 32 to 127 (0–9, A–Z, a–z), special characters, and FNC 1–4. 128A (Code Set A) – ASCII characters 00 to 95 (0–9, A–Z and control codes), special characters, and FNC 1–4.The shifts are done using code points 98 and 99 in code sets A and B, 100 in code sets A and C and 101 in code sets B and C to switch between them): Within each code set, some of the 103 data code points are reserved for shifting to one of the other two code sets. The initial subset is selected by using the appropriate start symbol. Code set C is used to efficiently encode digit strings. Together, code sets A and B cover all 128 ASCII characters. To represent all 128 ASCII values, it shifts among three code sets (A, B, C). A scanner seeing the reverse stop symbol then knows it must skip the 2-module bar and read the rest of the barcode in reverse.ĭespite its name, Code 128 does not have 128 distinct symbols, so it cannot represent 128 code points directly. When the stop pattern is read right-to-left, the reverse stop symbol (followed by a 2-module bar) is recognized. When the stop pattern is read left-to-right (the usual case), the stop symbol (followed by a 2-module bar) is recognized. The stop pattern permits bidirectional scanning. The stop pattern is composed of two overlapped symbols and has four bars. Each bar and space is 1 to 4 modules wide, and the symbols are fixed width: the sum of the widths of the three black bars and three white bars is 11 modules. All widths are multiples of a basic "module". Each symbol consists of three black bars and three white spaces of varying widths. The check symbol is calculated from a weighted sum ( modulo 103) of all the symbols.Ĭode 128 includes 108 symbols: 103 data symbols, 3 start symbols, and 2 stop symbols. Final bar (often considered part of the stop symbol).If you have both installed but you want a specific method, you can use $generator->useGd() or $generator->useImagick() to force your preference.1:quiet zone, 2:start code, 3:data, 4:checksum, 5:stop 6037701726651810 This package will use Imagick if that is installed, or fall back to GD. If you want to use PNG or JPG images, you need to install Imagick or the GD library. See example images for all supported barcode types A note about PNG and JPG images TYPE_CODE_32 (italian pharmaceutical code 'MINSAN').Because of the best scanner support, variable length and most chars supported. Most used types are TYPE_CODE_128 and TYPE_CODE_39. Please see wikipedia for supported chars and lengths per type. All types support different character sets or have mandatory lengths. $generatorSVG = new Picqer\ Barcode\ BarcodeGeneratorSVG() // Vector based SVG $generatorPNG = new Picqer\ Barcode\ BarcodeGeneratorPNG() // Pixel based PNG $generatorJPG = new Picqer\ Barcode\ BarcodeGeneratorJPG() // Pixel based JPG $generatorHTML = new Picqer\ Barcode\ BarcodeGeneratorHTML() // Pixel based HTML $generatorHTML = new Picqer\ Barcode\ BarcodeGeneratorDynamicHTML() // Vector based HTML Accepted barcode types
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