Provided by: opencl-1.2-man-doc_1.0~svn33624-1_all 
NAME
cl_image_format - The image format descriptor structure is defined as:
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
OpenCL Specification[1]
SEE ALSO
imageDescriptor(3clc), EXTENSION(3clc), clGetSupportedImageFormats(3clc),
clCreateImage(3clc)
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