# vImageHistogramSpecification_Planar8(_:_:_:_:) Specifies the histogram of an 8-bit planar buffer. ``` func vImageHistogramSpecification_Planar8(_ src: UnsafePointer, _ dest: UnsafePointer, _ desired_histogram: UnsafePointer, _ flags: vImage_Flags) -> vImage_Error ``` ## Parameters `src` The source vImage buffer. `dest` A pointer to the destination vImage buffer structure. You’re responsible for filling out the [`height`](/documentation/Accelerate/vImage_Buffer/height), [`width`](/documentation/Accelerate/vImage_Buffer/width), and [`rowBytes`](/documentation/Accelerate/vImage_Buffer/rowBytes) fields of this structure, and for allocating a data buffer of the appropriate size. On return, the data buffer this structure points to contains the destination image data. When you no longer need the data buffer, deallocate the memory to prevent memory leaks. `desired_histogram` The histogram that the operation applies to the source buffer. `flags` The options to use when performing the operation. If your code implements its own tiling or its own multithreading, pass [`kvImageDoNotTile`](/documentation/Accelerate/kvImageDoNotTile); otherwise, pass [`kvImageNoFlags`](/documentation/Accelerate/kvImageNoFlags). ## Return Value [`kvImageNoError`](/documentation/Accelerate/kvImageNoError); otherwise, one of the error codes in . ## Discussion Use this function to apply a histogram — that you’ve generated using [`vImageHistogramCalculation_Planar8(_:_:_:)`](/documentation/Accelerate/vImageHistogramCalculation_Planar8(_:_:_:)) — to another image. The following code applies a histogram to a planar vImage buffer: ```swift // `histogram` is a 256-element array. histogram.withUnsafeBufferPointer { // `buffer` is a `vImage_Buffer` structure. _ = vImageHistogramSpecification_Planar8(&buffer, &buffer, $0.baseAddress!, vImage_Flags(kvImageNoFlags)) } ``` ## See Also --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)