Built-in functions to read, write, and query image memory objects. Click an item in the table below for details about that function.
| read_imagef1d(3clc) for 1D | Do an element lookup in the 1D image object with or without a sampler, returning floating-point values. |
| read_imagei1d(3clc) 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_imageh1d(3clc) 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(3clc). |
| write_image1d(3clc) for 1D | Write color value to location in the 2D image object. The half type is enabled with cl_khr_fp16(3clc). |
| read_imagef2d(3clc) for 2D | Do an element lookup in the 2D image object with or without a sampler, returning floating-point values. |
| read_imagei2d(3clc) 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_imageh2d(3clc) 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(3clc). |
| write_image2d(3clc) for 2D | Write color value to location in the 2D image object. The half type is enabled with cl_khr_fp16(3clc). |
| read_imagef3d(3clc) for 3D | Do an element lookup in the 3D image object with or without a sampler, returning floating-point values. |
| read_imagei3d(3clc) 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_imageh3d(3clc) 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(3clc). |
| write_image3d(3clc) for 3D | Write color value to location in the 2D image object. The half type is enabled with cl_khr_fp16(3clc). |
| get_image_width(3clc) | Return the image width in pixels |
| get_image_height(3clc) | Return the image height in pixels. |
| get_image_depth(3clc) | Return the 3D image depth in pixels |
| get_image_channel_data_type(3clc) | Return the image channel data type |
| get_image_channel_order(3clc) | Return the image channel order |
| get_image_dim(3clc) | Return the image dimensions |
| get_image_array_size(3clc) | Return the number of images in an image array |
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 accessQualifiers(3clc) qualifier. write_image calls to image memory objects declared with the accessQualifiers(3clc) qualifier will generate a compilation error. Image memory objects that are being written to by a kernel should be declared with the accessQualifiers(3clc) qualifier. read_image calls to image memory objects declared with the accessQualifiers(3clc) 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.
OpenCL Specification[1]
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