iflRaw(3) Image Format Library C++ Reference Manual iflRaw(3)
NAME
iflRaw - raw image file format
DESCRIPTION
This image file format is used to access raw image data stored in a file.
The data must be organized in raster fashion; if the data is in pages
then the pages must all be fixed size (with partial pages at the image
edge padded to fill out the fixed size) and the pages must be ordered in
raster fashion themselves.
The raw format supports the full flexibility of the IFL model: all data
types, color models, orders, orientations and page sizes are supported.
Like all file formats supported by IFL you access raw images via the
generic object class (or the ilFileImg object for IL users).
The default extension for image files in the raw format is '.raw'. When
you create a file with that extension IFL will assume you want the raw
format, unless you override it with the iflFormat parameter or format
suffix, '#<format-name>'.
SPECIFYING DATA FORMATTING
To read a file in raw format you must use the format override suffix,
'#raw', and the format specific argument suffic, '%<format-specific-
args>' to tell IFL what the data format is since it can't determine it
from a file header. The data format is specified using a set of parameter
name/value pairs separated by spaces or '%' as the format specific
arguments. The paramter names and values may be abbreviated for
convenience. For example, to open a luminance, unsigned char, 512 by 512
image in a file named 'image.raw' you would use the file specification:
image.raw#raw%size=512,512%colormodel=luminance
or (assuming the name is used on a command line in csh):
image.raw#raw%'s=512,512 c=lum'
The full set of parameters and their possible values are enumerated in
the folowing sections.
size=<width>,<height>[,<depth>[,<components>]]
The size parameter specifies the image size. The depth (size of the Z
dimension) defaults to 1 if omitted. If omitted, the number of
components per pixel (size of the C dimension) defaults to the
appropriate value for the color model specified.
pagesize=<width>,<height>[,<depth>[,<components>]]
The pagesize parameter specifies the page size. If omitted the values
default to the same as the image size.
type=<data-type>
The type parameter specifies the data type of the pixel components.
Possible values are:
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iflRaw(3) Image Format Library C++ Reference Manual iflRaw(3)
bit data is single bit per component
char data is signed char (8-bit per component)
uchar data is unsigned char (8-bit); this is the default
short data is signed short (16-bit)
ushort data is unsigned short (16-bit)
int data is signed integer (32-bit)
uint data is unsigned integer (32-bit)
float data is float (32-bit floating point)
double data is float (64-bit floating point)
order=<dimension-order>
The order parameter specifies the ordering of the image dimensions, from
most rapidly varying, to least rapidly varying. Possible values are:
interleaved component dimension varies fastest, then x, then y, z last;
thus all the components of each pixel are grouped together;
this is the default
separate x dimension varies fastest, then y, then components, z
last; the data is stored with each component isolated in a
separate plane.
sequential x dimension varies fastest, then components, then y, z
last; all the components of a single row are grouped
together (seldom used)
orientation=<location-of-origin>
The orientation parameter defines the spatial interpretation of the
images x and y dimensions. It is defined in terms of the location of the
origin of the image (one of the four corners) and the direction of the x
and y dimension (whether x runs horizontally or vertically). The
combination of these two factors yields the eight orientations supported
by this format:
tl origin in top-left corner, x dimension is horizontal (y is vertical);
this is the default value
tr origin in top-right corner, x dimension is horizontal
bl origin in bottom-left corner, x dimension is horizontal
br origin in bottom-right corner, x dimension is horizontal
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iflRaw(3) Image Format Library C++ Reference Manual iflRaw(3)
lt origin in top-left corner, x dimension is vertical (y is horizontal)
rt origin in top-right corner, x dimension is vertical
rb origin in bottom-right corner, x dimension is vertical
lb origin in bottom-left corner, x dimension is vertical
colormodel=<interpretation-of-pixel-components>
The colormodel parameter defines the interpretation of the components of
the image's pixels. The possible values are:
luminance single component greyscale
negative single component inverted greyscale (minimum is white,
maximum is black)
la two component luminance plus alpha
palette single component color palette (indicies mapped through a
color map)
rgb red, green, blue triplets; this is the default
rgba RGB plus alpha (four components)
hsv hue, saturation, value (three components)
cmy cyan, magenta, yellow (three components)
cmyk cyan, magenta, yellow, black (four components)
ycc intensity, red-chrominace, green-chrominance (three
components)
mulitspectral arbitrary number of components, no interpretation (c size
must be given with size parameter)
offset=<offset-to-start-of-data>
The offset parameter gives the offset in bytes to the start of the image
data. The default value is zero.
minimum=<min-value-for-display-scaling>
The minimum parameter specifies the minimum value in the data for display
scaling purposes. The default is the minimum value for the component
data type or zero for floating point data.
maximum=<max-value-for-display-scaling>
The maximum parameter specifies the maximum value in the data for display
scaling purposes. The default is the maximum value for the component
data type or one for floating point data.
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SEE ALSO
iflFile, ilFileImg
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