|
typedef struct _cl_image_format {
cl_channel_order image_channel_order;
cl_channel_type image_channel_data_type;
} cl_image_format;
|
MEMBERS
image_channel_order
-
Specifies the number of channels and the channel layout i.e. the memory layout in which channels are stored in the image. Valid values are described in the table below.
Format Description CL_R, CL_Rx, or CL_A CL_INTENSITY This format can only be used if channel data type = CL_UNORM_INT8, CL_UNORM_INT16, CL_SNORM_INT8, CL_SNORM_INT16, CL_HALF_FLOAT, or CL_FLOAT. CL_LUMINANCE This format can only be used if channel data type = CL_UNORM_INT8, CL_UNORM_INT16, CL_SNORM_INT8, CL_SNORM_INT16, CL_HALF_FLOAT, or CL_FLOAT. CL_RG, CL_RGx, or CL_RA CL_RGB or CL_RGBx This format can only be used if channel data type = CL_UNORM_SHORT_565, CL_UNORM_SHORT_555 or CL_UNORM_INT101010. CL_RGBA CL_ARGB, CL_BGRA. This format can only be used if channel data type = CL_UNORM_INT8, CL_SNORM_INT8, CL_SIGNED_INT8 or CL_UNSIGNED_INT8.
image_channel_data_type
-
Describes the size of the channel data type. The number of bits per element determined by the image_channel_data_type and image_channel_order must be a power of two. The list of supported values is described in the table below.
Image Channel Data Type Description CL_SNORM_INT8 Each channel component is a normalized signed 8-bit integer value. CL_SNORM_INT16 Each channel component is a normalized signed 16-bit integer value. CL_UNORM_INT8 Each channel component is a normalized unsigned 8-bit integer value. CL_UNORM_INT16 Each channel component is a normalized unsigned 16-bit integer value. CL_UNORM_SHORT_565 Represents a normalized 5-6-5 3-channel RGB image. The channel order must be CL_RGB or CL_RGBx. CL_UNORM_SHORT_555 Represents a normalized x-5-5-5 4-channel xRGB image. The channel order must be CL_RGB or CL_RGBx. CL_UNORM_INT_101010 Represents a normalized x-10-10-10 4-channel xRGB image. The channel order must be CL_RGB or CL_RGBx. CL_SIGNED_INT8 Each channel component is an unnormalized signed 8-bit integer value. CL_SIGNED_INT16 Each channel component is an unnormalized signed 16-bit integer value. CL_SIGNED_INT32 Each channel component is an unnormalized signed 32-bit integer value. CL_UNSIGNED_INT8 Each channel component is an unnormalized unsigned 8-bit integer value. CL_UNSIGNED_INT16 Each channel component is an unnormalized unsigned 16-bit integer value. CL_UNSIGNED_INT32 Each channel component is an unnormalized unsigned 32-bit integer value. CL_HALF_FLOAT Each channel component is a 16-bit half-float value. CL_FLOAT Each channel component is a single precision floating-point value.
DESCRIPTION
For example, to specify a normalized unsigned 8-bit / channel RGBA image:
-
image_channel_order = CL_RGBA image_channel_data_type = CL_UNORM_INT8
image_channel_data_type values of CL_UNORM_SHORT_565, CL_UNORM_SHORT_555 and CL_UNORM_INT_101010 are special cases of packed image formats where the channels of each element are packed into a single unsigned short or unsigned int. For these special packed image formats, the channels are normally packed with the first channel in the most significant bits of the bitfield, and successive channels occupying progressively less significant locations. For CL_UNORM_SHORT_565, R is in bits 15:11, G is in bits 10:5 and B is in bits 4:0. For CL_UNORM_SHORT_555, bit 15 is undefined, R is in bits 14:10, G in bits 9:5 and B in bits 4:0. For CL_UNORM_INT_101010, bits 31:30 are undefined, R is in bits 29:20, G in bits 19:10 and B in bits 9:0.
OpenCL implementations must maintain the minimum precision specified by the number of bits in image_channel_data_type. If the image format specified by image_channel_order, and image_channel_data_type cannot be supported by the OpenCL implementation, then the call to clCreateImage(3clc) will return a NULL memory object.
SPECIFICATION
m[blue]OpenCL Specificationm[][1]
AUTHORS
The Khronos Group
COPYRIGHT
Copyright © 2007-2010 The Khronos Group Inc.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and/or associated documentation files (the "Materials"), to deal in the Materials without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Materials, and to permit persons to whom the Materials are furnished to do so, subject to the condition that this copyright notice and permission notice shall be included in all copies or substantial portions of the Materials.
NOTES
- 1.
-
OpenCL Specification
- page 92, section 5.3.1.1 - Image Format Descriptor