如何获取原始jpeg数据(但没有元标记/专有标记) [英] How to get raw jpeg data (but no metatags / proprietary markers)
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问题描述
我想获取原始jpeg数据-没有元数据. 我对jpeg的标准"感到非常困惑.
I want to get raw jpeg data - no metadata. I'm very confused looking at the jpeg "standards".
我对标记树"的理解有多正确?
How correct is my understanding of the marker "tree"?
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
https://ExifTool.org/TagNames/JPEG.html
http://www.media.mit.edu/pia /Research/deepview/exif.html
http://www.faqs.org/faqs /jpeg-faq/part1/section-15.html
推荐答案
除了SOS(0xFFDA),您可能还需要以下内容:
Besides the SOS (0xFFDA), you may also want the following:
0xFFDB DQT量化表 0xFFC4 DHT定义霍夫曼表
0xFFDB DQT Quantization Table 0xFFC4 DHT Define Huffman Table
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