Windows PowerShell command on Get-command TIFFRGBAImageGet

Manual Pages for UNIX Operating System command usage for man TIFFRGBAImageGet

Misc. Reference Manual Pages TIFFRGBAImage(3tiff)

NAME

TIFFRGBAImage, TIFFRGBAImageBegin, TIFFRGBAImageEnd, TIF-

FRGBAImageGet, TIFFRGBAImageOK, TIFFRGBAImageOriented - read

and decode an image into a raster

SYNOPSIS

#include

typedef unsigned char TIFFRGBValue;

typedef struct _TIFFRGBAImage TIFFRGBAImage;

int TIFFRGBAImageOK(TIFF* tif, char emsg[1024]); int TIFFRGBAImageBegin(TIFFRGBAImage* img, TIFF* tif, int stopOnError, char emsg[1024]);

int TIFFRGBAImageGet(TIFFRGBAImage* img, uint32* raster, uint32 width, uint32 height);

void TIFFRGBAImageEnd(TIFFRGBAImage* img);

The routines described here provide a high-level interface

through which TIFF images may be read into memory. Images

may be strip- or tile-based and have a variety of different

characteristics: bits/sample, samples/pixel, photometric, and so on. Decoding state is encapsulated in a TIFFRGBAImage

structure, which makes it possible to capture state for mul-

tiple images and quickly switch between them. The target raster format can be customized to the needs of a particular application by installing custom routines that manipulate image data according to application requirements. The default usage of these routines is as follows: 1. Use TIFFRGBAImageOK to check whether an image can be processed. 2. Use TIFFRGBAImageBegin to construct a decoder state block.

3. Use TIFFRGBAImageGet to read and decode an image into a

target raster. 4. Use TIFFRGBAImageEnd to release resources.

TIFFRGBAImageGet can be called multiple times to decode an

image using different state parameters. If multiple images are to be displayed and there is not enough space for each of the decoded rasters, multiple state blocks can be managed

and then calls can be made to TIFFRGBAImageGet as needed to

display an image. SunOS 5.10 Last change: 05 Apr 2004 1 Misc. Reference Manual Pages TIFFRGBAImage(3tiff) The generated raster is assumed to be an array of width

times height 32-bit entries, where width must be less than

or equal to the width of the image, and height may be any

non-zero size. If the raster dimensions are smaller than the

image, the image data is cropped to the raster bounds. If the raster height is greater than that of the image, then the image data is placed in the lower part of the raster. Note that the raster is assumed to be organized such that the pixel at location (x,y) is raster[y*width+x], with the

raster origin in the bottom-left corner.

EXTENDED DESCRIPTION

Raster pixels are 8-bit packed red, green, blue, alpha sam-

ples. The macros TIFFGetR, TIFFGetG, TIFFGetB, and TIFFGetA should be used to access individual samples. Images without Associated Alpha matting information have a constant Alpha of 1.0 (255).

TIFFRGBAImageGet converts non-8-bit images by scaling sample

values. Palette, grayscale, bilevel, CMYK, and YCbCr images are converted to RGB transparently. Raster pixels are returned uncorrected by any colorimetry information present in the directory. The parameter stopOnError specifies how to act if an error is encountered while reading the image. If stopOnError is

non-zero, then an error terminates the operation. Otherwise,

TIFFRGBAImageGet continues to process data until all of the

possible data in the image has been requested. Alternate Raster Formats To use the core support for reading and processing TIFF images, but write the resulting raster data in a different format, you need only override the "put methods" used to

store raster data. These methods are defined in the TIF-

FRGBAImage structure and initially set up by TIFFRGBAImage-

Begin to point to routines that pack raster data in the default ABGR pixel format. Two different routines are used according to the physical organization of the image data in the file: +o PlanarConfiguration=1 (packed samples) +o PlanarConfiguration=2 (separated samples). Note that this mechanism can be used to transform the data before storing the data in the raster. For example, you can convert data to colormap indices for display on a colormap display. SunOS 5.10 Last change: 05 Apr 2004 2 Misc. Reference Manual Pages TIFFRGBAImage(3tiff) Simultaneous Raster Store and Display An image can be displayed as the image is being into memory by overriding the put methods as described above to support alternate raster formats. Simply keep a reference to the default put methods set up by TIFFRGBAImageBegin and then invoke these methods before or after each display operation. For example, the tiffgt(1) utility uses the following put method to update the display as the raster is being filled: static void putContigAndDraw(TIFFRGBAImage* img, uint32* raster, uint32 x, uint32 y, uint32 w, uint32 h, int32 fromskew, int32 toskew, unsigned char* cp) { (*putContig)(img, raster, x, y, w, h, fromskew, toskew, cp); if (x+w == width) { w = width;

if (img->orientation == ORIENTATION_TOPLEFT)

lrectwrite(0, y-(h-1), w-1, y, raster-x-(h-1)*w);

else

lrectwrite(0, y, w-1, y+h-1, raster);

} } The original routine provided by the library is saved in the variable putContig. Supporting Additional TIFF Formats

The TIFFRGBAImage routines support the most commonly encoun-

tered flavors of TIFF. You can extend this support by over-

riding the "get method" invoked by TIFFRGBAImageGet to read

TIFF image data. Details of how to do this can be quite involved, it is best to make a copy of an existing get method and modify to suit the needs of an application. Diagnostics

All error messages are directed to the TIFFError(3tiff) rou-

tine.

Sorry, can not handle %d-bit pictures.

The image has a BitsPerSample value other than 1, 2, 4, 8, or 16.

Sorry, can not handle %d-channel images.

The image has a SamplesPerPixel value other than 1, 3, SunOS 5.10 Last change: 05 Apr 2004 3 Misc. Reference Manual Pages TIFFRGBAImage(3tiff) or 4. Missing needed "PhotometricInterpretation" tag. The image does not have a tag that describes how to display the data. No "PhotometricInterpretation" tag, assuming RGB. The image does not have a tag that describes how to display the data, but is assumed to be RGB because the image has 3 or 4 samples/pixel.

No "PhotometricInterpretation" tag, assuming min-is-black.

The image does not have a tag that describes how to display the data, but is assumed to be a grayscale or bilevel image because the image has 1 sample/pixel. No space for photometric conversion table.

There is insufficient memory for a table needed to con-

vert image samples to 8-bit RGB.

Missing required "Colormap" tag. A Palette image does not have a required Colormap tag. No space for tile buffer. There is insufficient memory to allocate an i/o buffer. No space for strip buffer. There is insufficient memory to allocate an i/o buffer. SunOS 5.10 Last change: 05 Apr 2004 4 Misc. Reference Manual Pages TIFFRGBAImage(3tiff) Can not handle format. The image has a format (combination of BitsPerSample, SamplesPerPixel, and PhotometricInterpretation) that TIFFReadRGBAImage cannot process. No space for B&W mapping table. There is insufficient memory to allocate a table needed to map grayscale data to RGB. No space for Palette mapping table. There is insufficient memory to allocate a table needed

to map data to 8-bit RGB.

All routines return 1 if the operation was successful. Oth-

erwise, 0 is returned if an error was encountered and sto-

pOnError is zero.

See attributes(5) for descriptions of the following attri-

butes:

____________________________________________________________

| ATTRIBUTE TYPE | ATTRIBUTE VALUE |

|_____________________________|_____________________________|

| Availability | image/library/libtiff |

|_____________________________|_____________________________|

| Interface stability | Uncommitted |

|_____________________________|_____________________________|

libtiff(3), TIFFOpen(3tiff), TIFFReadRGBAImage(3tiff), TIFFReadRGBAStrip(3tiff), TIFFReadRGBATile(3tiff) Samples must be either 1, 2, 4, 8, or 16 bits. Colorimetric

samples/pixel must be either 1, 3, or 4 (that is, Sam-

plesPerPixel minus ExtraSamples).

Palette image colormaps that appear to be incorrectly writ-

ten as 8-bit values are automatically scaled to 16-bits.

SunOS 5.10 Last change: 05 Apr 2004 5 Misc. Reference Manual Pages TIFFRGBAImage(3tiff)

Orientations other than bottom-left or top-left are not pro-

cessed correctly. This man page was originally written by Sam Leffler. Updated by Breda McColgan, Sun Microsystems Inc., 2004. SunOS 5.10 Last change: 05 Apr 2004 6