Synopsis

#include <IceT.h>

Description

The icetImageGetColorsuite of functions retrieve color data from images and the icetImageGetDepthfunctions retrieve depth data from images. Each function returns a pointer to an internal buffer within the image. Writing to this data changes the data within the image object itself. Use the icetImageGetColorand icetImageGetDepthfunctions from within drawing callbacks to pass image data back to IceT .

The pixel data is always tightly packed in horizontal major order. Color data that comprises tuples such as RGBA have the components for each pixel packed together in that order. The first entry in the array corresponds to the pixel in the lower left corner of the image. The next entry is immediately to the right of the first pixel, and so on. The dimensions of the array can be retrieved with the icetImageGetWidthand icetImageGetHeightfunctions.

Each of these functions returns a typed version of the image data array. They can only succeed if the type the request matches the internal type of the array. It is an error, for example, to request unsigned byte color data when the image stores images as floating point colors. You can use the icetImageGetColorFormatand icetImageGetDepthFormatto retrieve the format for the internal data storage (which also implies the base data type). You can also use the icetImageCopyColorand icetImageCopyDepthfunctions to convert the image data to whatever format you like.

Use icetImageGetColorubto retrieve an array of 8-bit unsigned bytes. Using this function is only valid if the color format is ICET_IMAGE_COLOR_RGBA_UBYTE.

Use icetImageGetColoruito retrieve an array of 32-bit unsigned integers. Using this function is only valid if the color format is ICET_IMAGE_COLOR_RGBA_UBYTE. In this case, each 32-bit integer represents all four RGBA channels. Accessing each pixel's color values as a single 32-bit integer is often faster than accessing it as 4 independent 8-bit integers as most modern architectures can access 32-bit memory boundaries faster than independent 8-bit boundaries.

Use icetImageGetColorfto retrieve an array of floating point color values. Using this function is only valid if the color format is ICET_IMAGE_COLOR_RGBA_FLOAT.

Use icetImageGetDepthfto retrieve an array of floating point depth values. Using this function is only valid if the depth format is ICET_IMAGE_DEPTH_FLOAT.

Return Value

Returns an appropriately typed array pointing to the internal color or depth values stored in the image object. If there is an error, NULL is returned.

The memory returned should not be freed. It is managed internally by IceT .

Errors

ICET_INVALID_OPERATION

 The internal color or depth format is incompatible with the type of  array the function retrieves.

Warnings

None.

Bugs

None known.

Notes

There is no mechanism to automatically determine the data type from the color or depth format enumeration (returned from icetImageGetColorFormat or icetImageGetDepthFormat).Instead, you must code internal logic to use an array of the appropriate type. The reasoning behind this decision is that the format encodes the data layout in addition to the data type, and your code most understand the basic semantics of the data to do anything worthwhile with it. If you want to write code that is indifferent to the underlying format of the image, use the icetImageCopyColor and icetImageCopyDepth functions to copy the data to a known format.

Copyright

Copyright (C)2010 Sandia Corporation

Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains certain rights in this software.

This source code is released under the New BSD License.

See Also

icetImageCopyColor(3), icetImageCopyDepth(3), icetImageGetColorFormat(3), icetImageGetDepthFormat(3)