Function

vImageConvert_ARGB8888toPlanar16Q12(_:_:_:_:_:_:)

Separates an ARGB8888 image into four Planar16Q12 images.

Declaration

func vImageConvert_ARGB8888toPlanar16Q12(_ src: UnsafePointer<vImage_Buffer>, _ alpha: UnsafePointer<vImage_Buffer>, _ red: UnsafePointer<vImage_Buffer>, _ green: UnsafePointer<vImage_Buffer>, _ blue: UnsafePointer<vImage_Buffer>, _ flags: vImage_Flags) -> vImage_Error

Parameters

src

A pointer to a vImage buffer structure that contains the source image whose data you want to separate.

alpha

A pointer to a vImage buffer data structure that represents the alpha channel destination. You're responsible for filling out the height, width, and rowBytes fields of this structure, and for allocating a data buffer of the appropriate size. When you no longer need the data buffer, you must deallocate the memory.

red

A pointer to a vImage buffer data structure that represents the red channel destination. You're responsible for filling out the height, width, and rowBytes fields of this structure, and for allocating a data buffer of the appropriate size. When you no longer need the data buffer, you must deallocate the memory.

green

A pointer to a vImage buffer data structure that represents the green channel destination. You're responsible for filling out the height, width, and rowBytes fields of this structure, and for allocating a data buffer of the appropriate size. When you no longer need the data buffer, you must deallocate the memory.

blue

A pointer to a vImage buffer data structure that represents the blue channel destination. You're responsible for filling out the height, width, and rowBytes fields of this structure, and for allocating a data buffer of the appropriate size. When you no longer need the data buffer, you must deallocate the memory.

flags

The options to use when performing the operation. If you plan to perform your own tiling or use multithreading, pass kvImageDoNotTile.

Return Value

kvImageNoError; otherwise, one of the error codes described in Data Types and Constants.

Discussion

The conversion from 8-bit float to 16-bit format with 12 fractional bits is:

uint16_t dest = ((src << 12) + 127)/255;

Source pixel values of 0 are mapped to 0, and source pixel values of 255 are mapped to 0x1000 (4096). No larger values are produced by this conversion, which provides some headroom to help subsequent operations avoid overflow or clipping.

This function doesn't operate in place.

See Also

Converting from ARGB Formats

func vImageConvert_ARGBFFFFtoRGBFFF(UnsafePointer<vImage_Buffer>!, UnsafePointer<vImage_Buffer>!, vImage_Flags) -> vImage_Error

Converts a four-channel ARGBFFFF image to a three-channel RGBFFF image by removing the alpha channel.

func vImageConvert_ARGB8888toRGB888(UnsafePointer<vImage_Buffer>, UnsafePointer<vImage_Buffer>, vImage_Flags) -> vImage_Error

Converts a four-channel ARGB8888 image to a three-channel RGB888 image by removing the alpha channel..

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