Image Read and Write Functions
Built-in functions to read, write, and query image memory objects. Click an item in the table below for details about that function.
| read_imagef for 1D | Do an element lookup in the 1D image object with or without a sampler, returning floating-point values. |
| read_image{i|ui} for 1D | Do an element lookup in the 1D image object with or without a sampler, returning unnormalized signed integer and unsigned integer values. |
| read_imageh for 1D | OPTIONAL function to do an element lookup in the 1D image object with or without a sampler, returning floating-point values. Enabled with cl_khr_fp16. |
| write_image {f|i|ui|h} for 1D |
Write color value to location in the 2D image object.
The half type is enabled with
cl_khr_fp16.
|
| read_imagef for 2D | Do an element lookup in the 2D image object with or without a sampler, returning floating-point values. |
| read_image{i|ui} for 2D | Do an element lookup in the 2D image object with or without a sampler, returning unnormalized signed integer and unsigned integer values. |
| read_imageh for 2D | OPTIONAL function to do an element lookup in the 2D image object with or without a sampler, returning floating-point values. Enabled with cl_khr_fp16. |
| write_image {f|i|ui|h} for 2D |
Write color value to location in the 2D image object.
The half type is enabled with
cl_khr_fp16.
|
| read_imagef for 3D | Do an element lookup in the 3D image object with or without a sampler, returning floating-point values. |
| read_image{i|ui} for 3D | Do an element lookup in the 3D image object with or without a sampler, returning unnormalized signed integer and unsigned integer values. |
| read_imageh for 3D | OPTIONAL function to do an element lookup in the 3D image object with or without a sampler, returning floating-point values. Enabled with cl_khr_fp16. |
| write_image {f|i|ui|h} for 3D |
Write color value to location in the 2D image object.
The half type is enabled with
cl_khr_fp16.
|
| get_image_width | Return the image width in pixels |
| get_image_height | Return the image height in pixels. |
| get_image_depth | Return the 3D image depth in pixels |
| get_image_channel_data_type | Return the image channel data type |
| get_image_channel_order | Return the image channel order |
| get_image_dim | Return the image dimensions |
| get_image_array_size | Return the number of images in an image array |
Notes
The built-in functions defined in this section can only be used with image memory objects. An image memory object can be accessed by specific function calls that read from and/or write to specific locations in the image.
Image memory objects that are being read by a kernel should be declared with the __read_only
qualifier. write_image calls to image memory objects declared with the
__read_only
qualifier will generate a compilation error. Image memory objects that
are being written to by a kernel should be declared with the __write_only qualifier.
read_image calls to image memory objects declared with the __write_only
qualifier will generate a compilation error. read_image and
write_image calls to the same image memory object in a kernel are
not supported.
The read_image calls returns a four component floating-point, integer or
unsigned integer color value. The color values returned by read_image
are identified as x, y, z, w where x refers to the red component,
y refers to the green component, z refers to the blue component
and w refers to the alpha component.
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