Sharp DIGITAL CAMERA Manuale Utente

sharpVISION™ Digital Camera 

™ 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. 

 

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. 

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.