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  • CIQRCodeGenerator Core Image Filter Reference

    https://developer.apple.com/library/prerelease/content/documentation/GraphicsImaging/Reference/CoreImageFilterReference/index.html#//apple_ref/doc/filter/ci/CIQRCodeGenerator

    Generates a Quick Response code (two-dimensional barcode) from input data.

    Localized Display Name

    CIQRCodeGenerator

    Parameters

    inputMessage

    The data to be encoded as a QR code. An NSData object whose display name is Message.

    inputCorrectionLevel

    A single letter specifying the error correction format. An NSString object whose display name is CorrectionLevel.

    Default value: M

    Discussion

    Generates an output image representing the input data according to the ISO/IEC 18004:2006 standard. The width and height of each module (square dot) of the code in the output image is one point. To create a QR code from a string or URL, convert it to an NSData object using the NSISOLatin1StringEncoding string encoding.

    The inputCorrectionLevel parameter controls the amount of additional data encoded in the output image to provide error correction. Higher levels of error correction result in larger output images but allow larger areas of the code to be damaged or obscured without. There are four possible correction modes (with corresponding error resilience levels):

    • L: 7%

    • M: 15%

    • Q: 25%

    • H: 30%

     
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  • 原文地址:https://www.cnblogs.com/feng9exe/p/5994929.html
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