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如何获取原始JPEG数据(但没有元标记/专有标记)

exif hex jpeg stream

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coolaj86 · 技术社区 · 15 年前

我想得到原始的JPEG数据-没有元数据。我对jpeg的“标准”感到困惑。

我对标记“树”的理解有多正确?

0xFFD8 - Identifies the file as an image
    0xFFE? - EXIF, JFIF, SPIFF, ICC, etc 
        0x???? - the length of the tag
    0xFFD8 - Start of Image
        0xFFE0 - should follow SOI as per spec, but often preceded by comments ???
        0x???? - Matrices, tags, random data ???

        There are never other markers in-between these markers? 
        Or these include the matrices and such?
        0xFFDA - Start of Stream - This is what I want, yes?
            0xXXXX - length of stream
            0xFFD9 - End of Stream (EOI)

        0x???? - Comment tags, extra exif, jfif info???
0xFFD9 - End of Image

0xFF00 - escaped 0xFF, not to be confused with a marker

这是我的阅读材料:

http://en.wikipedia.org/wiki/JPEG

http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html

http://www.media.mit.edu/pia/Research/deepview/exif.html

http://www.faqs.org/faqs/jpeg-faq/part1/section-15.html