visible to the end- 
h the highest reso- 
vel of the capture 
l in the hierarchy, 
age in half, verti- 
ien the image can 
Is square (fig. 2). 
9. It prescribes no 
ng constraint of 2 
ally any size and 
ed conveniently. 
from equation 1, 
larger resolution 
aller resolution: 
(1) 
  
  
building blocks. 
led tiles. (fig. 3). 
The tile size is set to 64 pixels square. Tiling allows FlashPix- 
optimized applications to work fast, with less I/0 and processing 
demands than traditional imaging software. Applications also 
can provide consistent zoom performance, because they're al- 
ways processing the same amount of data to fill the same size 
window, regardless of the resolution level. 
The following example image is R; (74) rows x C, (76) col- 
umns, organized into R, row x C, column tiles. For any image, 
the number of tiles per row (Ng) and the number of tiles per col- 
umn (N,) are: 
Ri Ci 
NR = = Nc = uH Q) 
A tiled image 
  
  
  
  
  
3.1.3. Structured storage 
The Flashpix format's structured storage feature behaves much 
like a file system within a file. It serves as a container, holding 
both "storages" and "streams," which act as virtual directories 
and virtual files inside the framework of the complete image 
file. Even while they're being treated separately, these pieces of 
data remain part of the image file - making all of the informa- 
tion easy to be managed. The F/ashPix format employs Micro- 
soft's OLE Structured Storage as the standardized "wrapper" 
FlashPix image object 
  
  
FlashFix image 
i if 
object Resolution 0 — 
Summary info. etit 
property set — Resolution 1 | —) 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Compobj . 
stream = 
Image cantents — Resolution a —; 
property set 
image info. ^ nmfil 
properly set — CC profile 
  
  
  
  
  
ee 
Extension §s 
property set 
  
  
  
  
Subimage 
header 
  
fig.4 
around FlashPix files, making them interoperable with OLE II 
as well as OpenDoc applications. The structured storage allows 
FlashPix files to serve as the native format within each applica- 
tion. Developers can put their own extensions in the structured 
Storage container, adding proprietary features and functions. 
These extended files are interoperable with other FlashPix- 
enabled readers, while the extended data (containing the pro- 
prietary features) can be used by specially enabled products. As 
a result, the same FlashPix file can be used within an applica- 
tion and also used exactly as-is by other applications or periph- 
erals. The storage structure also allows the addition of new 
FlashPix format features over time. Besides the proprietary ap- 
plication extensions described above, extensions will be pub- 
lished that will add new features while maintaining core com- 
patibility with original FlashPix-enabled readers and writers. 
3.1.4. Optional JPEG compression 
FlashPix format allows three compression options - JPEG com- 
pression, uncompressed and single-color compression. For tiles 
with image data that need to be compressed, the FlashPix for- 
mat employs standard JPEG compression with storage optimi- 
zation to reduce the file overhead generated by each tile. The 
uncompressed method is useful when storage space is plentiful, 
the storage device is fast and the processor speed is slow. For 
tiles in which all the pixels are the same color, single-color 
compression provides a 4096: 1 compression ratio and a signifi- 
cant performance improvement in reading the file. 
3.1.5. Multiple color space options 
The FlashPix format supports multiple color spaces. They in- 
clude: 
— a calibrated RGB color space definition, NIFRGB, de- 
signed specifically for the format 
— Photo YCC - a color encoding methodology employed by 
the Photo CD Image Pac format to represent color in a de- 
vice-independent manner 
— a calibrated monochrome option for grayscale images 
— uncalibrated versions of each of the above allow existing, 
uncalibrated files to be converted fo FlashPix files. 
FlashPix files may easily be used on a color managed system, 
using International Color Consortium (ICC) profiles to translate 
into the device independent Profile Connection Space (PCS). 
ICC profiles for both NIFRGB and YCC are provided. Because 
color space options are built directly into the new file format, 
the user is benefited with accurate color automatically. As long 
as a FlashPix file uses one of the reference color spaces, prod- 
ucts, services and systems can depend on the image data to be 
represented in a specific, accurate manner. In the case of uncali- 
brated images, applications will still process the data as though 
it were calibrated. 
3.1.6. Descriptive Information 
The FlashPix architecture lets user store descriptive data along 
with the image data in each FlashPix file. Descriptive informa- 
tion aids in developing image databases and describing the im- 
age source to applications and devices that will use the file. The 
FlashPix format supports non-image data areas including: file 
source, intellectual property, content description, camera infor- 
mation, per-picture camera settings, digital camera characteriza- 
tion, film description, original document scan description and 
scan device. 
—527—