Question

iOS中有很多关于PDF的讨论，我在这里找到了我的问题的所有答案，除了一个：我有一个包含简单矢量形状的PDF文件。是否可以提取该形状的路径数据，以便我可以直接在Quartz图层上绘制形状？

到目前为止，我可以浏览PDF文档，生成如下输出：

Object key Resources type: kCGPDFObjectTypeDictionary
Object key ProcSet type: kCGPDFObjectTypeArray with length 4
    Object key Array Object type: kCGPDFObjectTypeName PDF
    Object key Array Object type: kCGPDFObjectTypeName ImageB
    Object key Array Object type: kCGPDFObjectTypeName ImageC
    Object key Array Object type: kCGPDFObjectTypeName ImageI
Object key ColorSpace type: kCGPDFObjectTypeDictionary
    Object key Cs1 type: kCGPDFObjectTypeArray with length 2
        Object key Array Object type: kCGPDFObjectTypeName ICCBased
        Object key Array Object type: kCGPDFObjectTypeStream
            Object key Length type: kCGPDFObjectTypeInteger 737
            Object key N type: kCGPDFObjectTypeInteger 3
            Object key Alternate type: kCGPDFObjectTypeName DeviceRGB
            Object key Filter type: kCGPDFObjectTypeName FlateDecode
Object key XObject type: kCGPDFObjectTypeDictionary
    Object key Im1 type: kCGPDFObjectTypeStream
        Object key Length type: kCGPDFObjectTypeInteger 125
        Object key Type type: kCGPDFObjectTypeName XObject
        Object key Subtype type: kCGPDFObjectTypeName Image
        Object key Width type: kCGPDFObjectTypeInteger 62
        Object key Height type: kCGPDFObjectTypeInteger 49
        Object key Interpolate type: kCGPDFObjectTypeBoolean 1
        Object key ColorSpace type: kCGPDFObjectTypeArray with length 2
            Object key Array Object type: kCGPDFObjectTypeName ICCBased
            Object key Array Object type: kCGPDFObjectTypeStream
                Object key Length type: kCGPDFObjectTypeInteger 737
                Object key N type: kCGPDFObjectTypeInteger 3
                Object key Alternate type: kCGPDFObjectTypeName DeviceRGB
                Object key Filter type: kCGPDFObjectTypeName FlateDecode
        Object key SMask type: kCGPDFObjectTypeStream
            Object key Length type: kCGPDFObjectTypeInteger 36
            Object key Type type: kCGPDFObjectTypeName XObject
            Object key Subtype type: kCGPDFObjectTypeName Image
            Object key Width type: kCGPDFObjectTypeInteger 62
            Object key Height type: kCGPDFObjectTypeInteger 49
            Object key ColorSpace type: kCGPDFObjectTypeName DeviceGray
            Object key Interpolate type: kCGPDFObjectTypeBoolean 1
            Object key BitsPerComponent type: kCGPDFObjectTypeInteger 8
            Object key Filter type: kCGPDFObjectTypeName FlateDecode
        Object key BitsPerComponent type: kCGPDFObjectTypeInteger 8
        Object key Filter type: kCGPDFObjectTypeName FlateDecode

显然，有一个尺寸为62x49的图像和一个大小相同的面具（在形状周围，PDF是透明的）。图像绝对是矢量图形，我可以将其缩放到各种尺寸而不会丢失质量。那么frack是路径信息呢？

感谢您的任何信息！

最佳，本杰明

Answer 1

图像嵌入PDF文件本身。它没有路径 - 它不是外部文件。相反，它是PDF中的 stream 对象。您将需要解压缩（“膨胀”）该流对象（根据该XObject上的Filter值使用“flate”进行压缩），然后将其包含的PDF绘图/渲染命令解析并转换为等效的Quartz调用。这样做绝对是不琐碎 - 抱歉。（我建议找一个能为你做这件事的图书馆。）

祝你好运！

Answer 2

GitHub上有一个小项目，它使用CGPDFScannerScan（）来提取矢量数据：http://github.com/depth42/PWDynamicPDFImage

iOS从PDF中提取矢量图形

2 个答案: