我想获取原始的jpeg数据-没有元数据。我对jpeg的“标准”感到非常困惑。
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
https://ExifTool.org/TagNames/JPEG.html
除了SOS(0xFFDA),您可能还需要以下内容:
0xFFDB DQT量化表0xFFC4 DHT定义霍夫曼表