Book Image

OpenCL Programming by Example

Book Image

OpenCL Programming by Example

Overview of this book

Research in parallel programming has been a mainstream topic for a decade, and will continue to be so for many decades to come. Many parallel programming standards and frameworks exist, but only take into account one type of hardware architecture. Today computing platforms come with many heterogeneous devices. OpenCL provides royalty free standard to program heterogeneous hardware. This guide offers you a compact coverage of all the major topics of OpenCL programming. It explains optimization techniques and strategies in-depth, using illustrative examples and also provides case studies from diverse fields. Beginners and advanced application developers will find this book very useful. Beginning with the discussion of the OpenCL models, this book explores their architectural view, programming interfaces and primitives. It slowly demystifies the process of identifying the data and task parallelism in diverse algorithms. It presents examples from different domains to show how the problems within different domains can be solved more efficiently using OpenCL. You will learn about parallel sorting, histogram generation, JPEG compression, linear and parabolic regression and k-nearest neighborhood, a clustering algorithm in pattern recognition. Following on from this, optimization strategies are explained with matrix multiplication examples. You will also learn how to do an interoperation of OpenGL and OpenCL. "OpenCL Programming by Example" explains OpenCL in the simplest possible language, which beginners will find it easy to understand. Developers and programmers from different domains who want to achieve acceleration for their applications will find this book very useful.
Table of Contents (18 chapters)
OpenCL Programming by Example
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Copying and filling images


The write and read functions help to copy the data buffer from the host to the device memory or vice versa. There is another function which helps in copying the data from one OpenCL image buffer object to another. This is specified as src_image and dst_image in the following function:

cl_int clEnqueueCopyImage (cl_command_queue command_queue,cl_mem src_image,cl_mem dst_image,const size_t *src_origin,const size_t *dst_origin,const size_t *region,cl_uint num_events_in_wait_list,const cl_event *event_wait_list,cl_event *event)

The src_origin and dst_origin parameter have the usual meaning as specified for the origin parameter for the read and write routines in the previous section.

The region parameter also has the same meaning as specified in the previous section.

This function can be used to do one of the following tasks:

  • Copy a 1D image object to a 1D image object, 2D image object, or 2D slice of a 3D image object and vice-versa

  • Copy a 1D image object to a scan line...