Question

我想获取原始jpeg数据 - 没有元数据。我很困惑地看着jpeg“标准”。

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

Answer 1

除了SOS（0xFFDA）之外，您可能还需要以下内容：

0xFFDB DQT量化表 0xFFC4 DHT定义霍夫曼表

如何获取原始jpeg数据（但没有元标记/专有标记）

1 个答案: