"java jpeg converter for odd image types" Code Answer

the first field after ffe0 marker is the length field. it's 16 bits long big endian and includes the length of the length field but not the ffe0 marker. just copy the ffe0 marker and the associated data from an existing jpeg and fit it in between ffd8 and ffe1.

according to the jfif standard, the jfif header should follow immediately after soi (ffd8). every jpeg without a jfif header is essentially broken as there's no way of knowing what color coding is used. of course there's the adobe jpeg's but they don't really count. if there's a jfif header, you know that the image is coded in ycbcr. if there's no jfif header, you could maybe assume it's ycbcr, but you can't know for sure.

you can read more about the jfif standard here: http://www.w3.org/graphics/jpeg/jfif3.pdf

By jmdeldin on June 21 2022