Package org.lwjgl.vulkan

Class QCOMImageProcessing

java.lang.Object
org.lwjgl.vulkan.QCOMImageProcessing
public final class QCOMImageProcessing extends Object
GPUs are commonly used to process images for various applications from 3D graphics to UI and from composition to compute applications. Simple scaling and filtering can be done with bilinear filtering, which comes for free during texture sampling. However, as screen sizes get larger and more use cases rely on GPU such as camera and video post-processing needs, there is increasing demand for GPU to support higher order filtering and other advanced image processing.

This extension introduces a new set of SPIR-V built-in functions for image processing. It exposes the following new imaging operations

  • The OpImageSampleWeightedQCOM instruction takes 3 operands: sampled image, weight image, and texture coordinates. The instruction computes a weighted average of an MxN region of texels in the sampled image, using a set of MxN weights in the weight image.
  • The OpImageBoxFilterQCOM instruction takes 3 operands: sampled image, box size, and texture coordinates. Note that box size specifies a floating-point width and height in texels. The instruction computes a weighted average of all texels in the sampled image that are covered (either partially or fully) by a box with the specified size and centered at the specified texture coordinates.
  • The OpImageBlockMatchSADQCOM and OpImageBlockMatchSSDQCOM instructions each takes 5 operands: target image, target coordinates, reference image, reference coordinates, and block size. Each instruction computes an error metric, that describes whether a block of texels in the target image matches a corresponding block of texels in the reference image. The error metric is computed per-component. OpImageBlockMatchSADQCOM computes "Sum Of Absolute Difference" and OpImageBlockMatchSSDQCOM computes "Sum of Squared Difference".

Each of the image processing instructions operate only on 2D images. The instructions do not-support sampling of mipmap, multi-plane, multi-layer, multi-sampled, or depth/stencil images. The instructions can be used in any shader stage.

Implementations of this extension should support these operations natively at the HW instruction level, offering potential performance gains as well as ease of development.

Name String
VK_QCOM_image_processing
Extension Type
Device extension
Registered Extension Number
441
Revision
1
Extension and Version Dependencies
VK_KHR_format_feature_flags2 or Version 1.3
API Interactions
  • Interacts with VK_VERSION_1_3
  • Interacts with VK_KHR_format_feature_flags2
SPIR-V Dependencies
Contact
Extension Proposal
VK_QCOM_image_processing
Other Extension Metadata
Last Modified Date
2022-07-08
Interactions and External Dependencies
Contributors
  • Jeff Leger, Qualcomm Technologies, Inc.
  • Ruihao Zhang, Qualcomm Technologies, Inc.