Note on 16 bit grayscale formats – Sharp VISION DIGITAL CAMERA User Manual
Page 33
sharpVISION™ Digital Camera
sharpVISION
™ User Manual
33
typedef struct _RCIMG_HEADER
{
unsigned long nSize;
// size of this header
unsigned long nPages;
//
number
of
pages/frames
unsigned long nWidth;
//
image
width
unsigned long nHeight;
// image height
unsigned long nBPP;
// bits per pixel
unsigned long userData[64];
// user data array
} RCIMG_HEADER, *PRCIMG_HEADER;
Members
nSize: size of the structure in bytes. It should be 84.
nPages: number of images contained in the file
nWidth: width of each image in pixels.
nHeight: height of each image in pixels.
nBPP: number of bits per pixels (8, 10 or12)
userData: an array of 64 unsigned long that may be user by the user to store other
information.
8.1.9.3. Data
arrays
The image header is followed by the images data. Images are stored contiguously in
compressed format. The first four bytes contains the size of the compressed buffer, followed
by image data.
Data compression is done using ZLIB library version 1.1.4, which is free and available for
download at the URL
.
The compression algorithm used by ZLIB is a variation of LZ77 (Lempel-Ziv 1977). It finds
duplicated strings in the input data. The second occurrence of a string is replaced by a
pointer to the previous string, in the form of a pair (distance, length). Distances are limited to
32K bytes, and lengths are limited to 258 bytes. When a string does not occur anywhere in
the previous 32K bytes, it is emitted as a sequence of literal bytes.
8.1.10.
Note on 16 bit grayscale formats
10-bit images acquired from the camera may be saved in different 16 bit formats. These
formats include TIF, PNG, MPT, MRF and MCF. Since 16 bit grayscale format is not a
standard, not all the applications for image processing may correctly display the saved
images.