Accelerate Sample Code

Applying transformations to selected colors in an image

Desaturate a range of colors in an image with a multidimensional lookup table.

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Calculating the dominant colors in an image

Find the main colors in an image by implementing k-means clustering using the Accelerate framework.

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Creating an audio unit extension using the vDSP library

Add biquadratic filter audio-effect processing to apps like Logic Pro X and GarageBand with the Accelerate framework.

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Cropping to the subject in a chroma-keyed image

Convert a chroma-key color to alpha values and trim transparent pixels using Accelerate.

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Sharing texture data between the Model I/O framework and the vImage library

Use Model I/O and vImage to composite a photograph over a computer-generated sky.

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Creating an audio unit extension using the vDSP library

Add biquadratic filter audio-effect processing to apps like Logic Pro X and GarageBand with the Accelerate framework.

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Equalizing Audio with vDSP

Shape audio output using discrete cosine transforms and biquadratic filters.

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Adjusting Saturation and Applying Tone Mapping

Convert an RGB image to discrete luminance and chrominance channels, and apply color and contrast treatments.

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Adjusting the Brightness and Contrast of an Image

Use a gamma function to apply a linear or exponential curve.

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Adjusting the Hue of an Image

Convert an RGB image to L*a*b* color space and apply hue adjustment.

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Applying Tone Curve Adjustments to Images

Use the vImage library's polynomial transform to apply tone curve adjustments to images.

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Enhancing Image Contrast with Histogram Manipulation

Enhance and adjust the contrast of an image with histogram equalization and contrast stretching.

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Specifying Histograms with vImage

Calculate the histogram of one image and apply it to a second image.

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Compressing and Decompressing Data with Buffer Compression

Compress a string, write it to the file system, and decompress the same file using buffer compression.

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Compressing and Decompressing Data with Input and Output Filters

Compress and decompress streamed or from-memory data, using input and output filters.

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Compressing and Decompressing Files with Stream Compression

Perform compression or the appropriate kind of decompression to a file based on its path extension.

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Compressing and Decompressing Files with Swift Stream Compression

Perform compression for all files and decompression for files with supported extension types.

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Applying Color Transforms to Images with a Multidimensional Lookup Table

Create a multidimensional lookup table to convert RGB images to CMYK.

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Building a Basic Conversion Workflow

Learn the fundamentals of the convert-any-to-any function by converting a CMYK image to an RGB image.

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Converting Color Images to Grayscale

Convert a color image to grayscale using matrix multiplication.

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Converting Luminance and Chrominance Planes to an ARGB Image

Create a displayable ARGB image from the luminance and chrominance information supplied by your device's camera

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Sharing texture data between the Model I/O framework and the vImage library

Use Model I/O and vImage to composite a photograph over a computer-generated sky.

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Standardizing Arbitrary Image Formats for Processing

Convert assets with disparate color spaces and bit depths to a standard working format for applying vImage operations.

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Adding a Bokeh Effect

Simulate a bokeh effect by applying dilation.

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Blurring an Image

Filter an image by convolving it with custom and high-speed kernels.

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Applying vImage Operations to Video Sample Buffers

Use vImage's convert-any-to-any function to perform real-time image processing of video frames streamed from your device's camera.

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Reading From and Writing to Core Video Pixel Buffers

Transfer image data between Core Video pixel buffers and vImage buffers to integrate vImage operations into a Core Image workflow.

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Real-Time Video Effects with vImage

Use vImage to apply effects to a video feed in real time.

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Compresing and Saving a String to the File System

Compress the contents of a Unicode string and store the result on the file system.

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Compressing File System Directories

Compress the contents of an entire directory and store the result on the file system.

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Compressing Single Files

Compress a single file and store the result on the file system.

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Decompressing and Extracting an Archived Directory

Recreate an entire file system directory from an archive file.

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Decompressing and Parsing an Archived String

Recreate a string from an archive file.

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Decompressing Single Files

Recreate a single file from a compressed file.

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Data Packing for Fourier Transforms

Learn how vDSP packs frequency-domain data produced by Fourier transform routines.

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Finding the Component Frequencies in a Composite Sine Wave

Use 1D fast Fourier transform to compute the frequency components of a signal.

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Halftone Descreening with 2D Fast Fourier Transform

Reduce or remove periodic artifacts from images.

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Signal Extraction from Noise

Use Accelerate's discrete cosine transform to remove noise from a signal.

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Using Windowing with Discrete Fourier Transforms

Multiply signal data by window sequence values to reduce spectral leakage.

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Applying Geometric Transforms to Images

Reflect, shear, rotate, and scale image buffers using vImage.

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Applying transformations to selected colors in an image

Desaturate a range of colors in an image with a multidimensional lookup table.

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Applying vImage Operations to Regions of Interest

Limit the effect of vImage operations to rectangular regions of interest.

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Building a Basic Image-Processing Workflow

Resize an image with vImage.

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Compositing Images with Alpha Blending

Combine two images by using alpha blending to create a single output.

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Compositing Images with vImage Blend Modes

Combine two images by using blend modes to create a single output.

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Creating a Core Graphics Image Format

Provide descriptions of Core Graphics image formats for conversions to and from vImage.

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Creating a Core Graphics Image from a vImage Buffer

Create displayable representations of vImage buffers.

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Creating and Populating Buffers from Core Graphics Images

Initialize vImage buffers from Core Graphics images.

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Cropping to the subject in a chroma-keyed image

Convert a chroma-key color to alpha values and trim transparent pixels using Accelerate.

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Optimizing Image Processing Performance

Improve your app's performance by converting image buffer formats from interleaved to planar.

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Reducing Artifacts in Resampled Images

Avoid ringing effects introduced by the default Lanczos algorithm when scaling an image by using a custom resampling filter.

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Computing the Mel Spectrum Using Linear Algebra

Generate a real-time mel spectrogram of audio using matrix multiplication.

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Denoising an Image Using Linear Algebra

Reduce noise in an image using singular value decomposition (SVD).

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Finding an Interpolating Polynomial Using the Vandermonde Method

Use LAPACK to solve a linear system and find an interpolating polynomial to construct new points between a series of known data points.

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Solving Systems of Linear Equations with LAPACK

Select the optimal LAPACK routine to solve a system of linear equations.

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Solving systems of linear equations with LAPACK

Select the optimal LAPACK routine to solve a system of linear equations.

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Finding an interpolating polynomial using the Vandermonde method

Use LAPACK to solve a linear system and find an interpolating polynomial to construct new points between a series of known data points.

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Controlling vDSP Operations with Stride

Operate selectively on the elements of a vector at regular intervals.

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Resampling a Signal with Decimation

Reduce the sample rate of a signal, by specifying a decimation factor and applying a custom antialiasing filter.

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Use Linear Interpolation to Construct New Data Points

Fill the gaps in arrays of numerical data using linear interpolation.

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Using vDSP for Vector-based Arithmetic

Increase the performance of common mathematical tasks with vDSP vector-vector and vector-scalar operations.

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Creating a Sparse Matrix from Coordinate Format Arrays

Use separate coordinate format arrays to create sparse matrices.

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Creating Sparse Matrices

Create sparse matrices for factorization and solving systems.

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Implementing Iterative Methods

Use iterative methods to solve large problems faster and with a lower memory overhead than with direct methods.

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Solving Systems Using Direct Methods

Use direct methods to solve systems of equations where the coefficient matrix is sparse.

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Solving Systems Using Iterative Methods

Use iterative methods to solve systems of equations where the coefficient matrix is sparse.

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Creating Sparse Matrices

Create sparse matrices for factorization and solving systems.

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Implementing Iterative Methods

Use iterative methods to solve large problems faster and with a lower memory overhead than with direct methods.

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Solving Systems Using Direct Methods

Use direct methods to solve systems of equations where the coefficient matrix is sparse.

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Solving Systems Using Iterative Methods

Use iterative methods to solve systems of equations where the coefficient matrix is sparse.

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Creating a Sparse Matrix from Coordinate Format Arrays

Use separate coordinate format arrays to create sparse matrices.

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Rotating a Cube by Transforming Its Vertices

Rotate a cube through a series of keyframes using quaternion interpolation to transition between them.

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Working with Matrices

Solve simultaneous equations and transform points in space.

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Working with Quaternions

Rotate points around the surface of a sphere, and interpolate between them.

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Working with Vectors

Use vectors to calculate geometric values, calculate dot products and cross products, and interpolate between values.

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Calculating the dominant colors in an image

Find the main colors in an image by implementing k-means clustering using the Accelerate framework.

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Finding the Sharpest Image in a Sequence of Captured Images

Share image data between vDSP and vImage to compute the sharpest image from a bracketed photo sequence.

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Visualizing Sound as an Audio Spectrogram

Share image data between vDSP and vImage to visualize audio that a device microphone captures.

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