.TH "MPSImagePyramid" 3 "Mon Jul 9 2018" "Version MetalPerformanceShaders-119.3" "MetalPerformanceShaders.framework" \" -*- nroff -*-
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.SH NAME
MPSImagePyramid
.SH SYNOPSIS
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.PP
.PP
\fC#import <MPSImageConvolution\&.h>\fP
.PP
Inherits \fBMPSUnaryImageKernel\fP\&.
.PP
Inherited by \fBMPSImageGaussianPyramid\fP, and \fBMPSImageLaplacianPyramid\fP\&.
.SS "Instance Methods"

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.RI "(nonnull instancetype) \- \fBinitWithDevice:\fP"
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.RI "(nonnull instancetype) \- \fBinitWithDevice:centerWeight:\fP"
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.RI "(nonnull instancetype) \- \fBinitWithDevice:kernelWidth:kernelHeight:weights:\fP"
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.RI "(nullable instancetype) \- \fBinitWithCoder:device:\fP"
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.SS "Properties"

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.RI "NSUInteger \fBkernelHeight\fP"
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.RI "NSUInteger \fBkernelWidth\fP"
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.SS "Additional Inherited Members"
.SH "Detailed Description"
.PP 
The \fBMPSImagePyramid\fP is a base class for creating different kinds of pyramid images 
.PP
.nf
        Currently supported pyramid-types are:
        @ref MPSImageGaussianPyramid

        The Gaussian image pyramid kernel is enqueued as a in-place operation using
        @ref MPSUnaryImageKernel::encodeToCommandBuffer:inPlaceTexture:fallbackCopyAllocator:
        and all mipmap levels after level=1, present in the provided image are filled using
        the provided filtering kernel. The fallbackCopyAllocator parameter is not used.

        The Gaussian image pyramid filter ignores @ref clipRect and @ref offset and fills
        the entire mipmap levels.

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\fBNote:\fP
.RS 4
Make sure your texture type is compatible with mipmapping and supports texture views (see \fBMTLTextureUsagePixelFormatView\fP)\&. 
.PP
Recall the size of the nth mipmap level: 
.PP
.nf
w_n = max(1, floor(w_0 / 2^n))
h_n = max(1, floor(h_0 / 2^n)),

.fi
.PP
 where w_0, h_0 are the zeroth level width and height\&. ie the image dimensions themselves\&. 
.RE
.PP

.SH "Method Documentation"
.PP 
.SS "\- (nullable instancetype) \fBinitWithCoder:\fP (NSCoder *__nonnull) aDecoder(nonnull id< MTLDevice >) device"
\fBNSSecureCoding\fP compatability  See \fBMPSKernel::initWithCoder\fP\&. 
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\fBParameters:\fP
.RS 4
\fIaDecoder\fP The NSCoder subclass with your serialized \fBMPSCNNPooling\fP 
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\fIdevice\fP The MTLDevice on which to make the \fBMPSCNNPooling\fP 
.RE
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\fBReturns:\fP
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\fBA\fP new \fBMPSCNNPooling\fP object, or nil if failure\&. 
.RE
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.PP
Reimplemented from \fBMPSUnaryImageKernel\fP\&.
.SS "\- (nonnull instancetype) initWithDevice: (nonnull id< MTLDevice >) device"
Initialize a downwards 5-tap image pyramid with the default filter kernel and device 
.PP
\fBParameters:\fP
.RS 4
\fIdevice\fP The device the filter will run on
.RE
.PP
The filter kernel is the outer product of w = [ 1/16, 1/4, 3/8, 1/4, 1/16 ]^T, with itself
.PP
\fBReturns:\fP
.RS 4
\fBA\fP valid object or nil, if failure\&. 
.RE
.PP

.PP
Reimplemented from \fBMPSUnaryImageKernel\fP\&.
.SS "\- (nonnull instancetype) \fBinitWithDevice:\fP (nonnull id< MTLDevice >) device(float) centerWeight"
Initialize a downwards 5-tap image pyramid with a central weight parameter and device 
.PP
\fBParameters:\fP
.RS 4
\fIdevice\fP The device the filter will run on 
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\fIcenterWeight\fP Defines form of the filter-kernel through the outer product ww^T, where w = [ (1/4 - a/2), 1/4, a, 1/4, (1/4 - a/2) ]^T and 'a' is centerWeight\&.
.RE
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\fBReturns:\fP
.RS 4
\fBA\fP valid object or nil, if failure\&. 
.RE
.PP

.SS "\- (nonnull instancetype) \fBinitWithDevice:\fP (nonnull id< MTLDevice >) device(NSUInteger) kernelWidth(NSUInteger) kernelHeight(const float *__nonnull) kernelWeights"
Initialize a downwards n-tap pyramid with a custom filter kernel and device 
.PP
\fBParameters:\fP
.RS 4
\fIdevice\fP The device the filter will run on 
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\fIkernelWidth\fP The width of the filtering kernel\&. See \fBMPSImageConvolution\fP\&. 
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\fIkernelHeight\fP The height of the filtering kernel\&. See \fBMPSImageConvolution\fP\&. 
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\fIkernelWeights\fP \fBA\fP pointer to an array of kernelWidth * kernelHeight values to be used as the kernel\&. These are in row major order\&. See \fBMPSImageConvolution\fP\&.
.RE
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\fBReturns:\fP
.RS 4
\fBA\fP valid object or nil, if failure\&. 
.RE
.PP

.SH "Property Documentation"
.PP 
.SS "\- kernelHeight\fC [read]\fP, \fC [nonatomic]\fP, \fC [assign]\fP"
The height of the filter window\&. Must be an odd number\&. 
.SS "\- kernelWidth\fC [read]\fP, \fC [nonatomic]\fP, \fC [assign]\fP"
The width of the filter window\&. Must be an odd number\&. 

.SH "Author"
.PP 
Generated automatically by Doxygen for MetalPerformanceShaders\&.framework from the source code\&.