Write color value to location in a 1d image object.
void write_imagef(image1d_t image, int coord, float4 color); void write_imagef(image1d_buffer_t image, int coord, float4 color); void write_imagef(image1d_array_t image, int2 coord, float4 color); void write_imagei(image1d_t image, int coord, int4 color); void write_imagei(image1d_buffer_t image, int coord, int4 color); void write_imagei(image1d_array_t image, int2 coord, int4 color); void write_imageui(image1d_t image, int coord, uint4 color); void write_imageui(image1d_buffer_t image, int coord, uint4 color); void write_imageui(image1d_array_t image, int2 coord, uint4 color); void write_imageh(image1d_t image, int coord, half4 color); void write_imageh(image1d_buffer_t image, int coord, half4 color); void write_imageh(image1d_array_t image, int2 coord, half4 color);
write_imagef can only be used with image objects created with image_channel_data_type set to one of the pre-defined packed formats or set to CL_SNORM_INT8, CL_UNORM_INT8, CL_SNORM_INT16, CL_UNORM_INT16, CL_HALF_FLOAT, or CL_FLOAT. Appropriate data format conversion will be done to convert channel data from a floating-point value to actual data format in which the channels are stored.
write_imagei functions can only be used with image objects created with image_channel_data_type set to one of the following values: CL_SIGNED_INT8, CL_SIGNED_INT16, or CL_SIGNED_INT32.
write_imageui functions can only be used with image objects created with image_channel_data_type set to one of the following values: CL_UNSIGNED_INT8, CL_UNSIGNED_INT16, or CL_UNSIGNED_INT32.
The write_imageh functions are enabled when the half type is supported and can only be used with image objects created with image_channel_data_type set to one of the pre-defined packed formats or set to CL_SNORM_INT8, CL_UNORM_INT8, CL_SNORM_INT16, CL_UNORM_INT16 or CL_HALF_FLOAT. Appropriate data format conversion will be done to convert channel data from a floating-point value to actual data format in which the channels are stored. Functions that take image1d_t or image1d_buffer_t.PP The functions that take image1d_t or image1d_buffer_t write the color value to the location specified by coord in the 1D image or 1D image buffer object specified by image. Appropriate data format conversion to the specified image format is done before writing the color value. coord is considered to be unnormalized coordinates and must be in the range 0... image width - 1.
for functions taking image1d_t or image1d_buffer_t, the behavior of write_imagef, write_imagei, write_imageui, and write_imageh for image objects created with image_channel_data_type values not specified in the description above or with coordinate values that are not in the range (0... image width - 1), is undefined. Functions that take image1d_array_t.PP The functions that take image1d_array_t write the color value to the location specified by coord.x in the 1D image identified by coord.y in the 1D image array specified by image. Appropriate data format conversion to the specified image format is done before writing the color value. coord.x and coord.y are considered to be unnormalized coordinates and must be in the range 0 ... image width - 1 and 0 ... image number of layers - 1.
For functions taking image1d_array_t, the behavior of write_imagef, write_imagei and write_imageui for image objects created with image_channel_data_type values not specified in the description above or with (x, y) coordinate values that are not in the range (0 ... image width - 1, 0 ...image number of layers - 1), respectively, is undefined.
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.
\m[blue]OpenCL Specification\m[]\s-2\u[1]\d\s+2
imageFunctions(3clc)
The Khronos Group
Copyright © 2007-2011 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.
OpenCL Specification
page 292, section 6.12.14 - Image Read and Write Functions