get_image_channel_order

Return the image channel data order.

int get_image_channel_order ( image2d_t image)
int get_image_channel_order ( image3d_t image)

Description

Return the image channel order. Valid values are:


CLK_A
CLK_R
CLK_Rx
CLK_RG
CLK_RGx
CLK_RA
CLK_RGB
CLK_RGBx
CLK_RGBA
CLK_ARGB
CLK_BGRA
CLK_INTENSITY
CLK_LUMINANCE

Notes

The values returned by get_image_channel_order as shown above with the CLK_ prefixes correspond to the CL_ prefixes used to describe the image channel order and data type in the table of supported names and values in clCreateSubBuffer and list of supported Image Channel Order Values for clCreateImage3D. For example, both CL_UNORM_INT8 and CLK_UNORM_INT8 refer to an image channel data type that is an unnormalized unsigned 8-bit integer.

The following table describes the mapping of the number of channels of an image element to the appropriate components in the float4, int4 or uint4 vector data type for the color values returned by read_image{f|i|ui} or supplied to write_image{f|i|ui}. The unmapped components will be set to 0.0 for red, green and blue channels and will be set to 1.0 for the alpha channel.

Channel Order float4, int4 or unsigned int4 components of channel data
CL_R, CL_Rx (r, 0.0, 0.0, 1.0)
CL_A (0.0, 0.0, 0.0, a)
CL_RG, CL_RGx (r, g, 0.0, 1.0)
CL_RA (r, 0.0, 0.0, a)
CL_RGB, CL_RGBx (r, g, b, 1.0)
CL_RGBA, CL_BGRA, CL_ARGB (r, g, b, a)
CL_INTENSITY (I, I, I, I)
CL_LUMINANCE (L, L, L, 1.0)

A kernel that uses a sampler with the CL_ADDRESS_CLAMP addressing mode with multiple images may result in additional samplers being used internally by an implementation. If the same sampler is used with multiple images called via read_image{f | i | ui}, then it is possible that an implementation may need to allocate an additional sampler to handle the different border color values that may be needed depending on the image formats being used. These implementation allocated samplers will count against the maximum sampler values supported by the device and given by CL_DEVICE_MAX_SAMPLERS. Enqueuing a kernel that requires more samplers than the implementation can support will result in a CL_OUT_OF_RESOURCES error being returned.

Specification

OpenCL Specification

Also see

Image Functions

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