/// <summary>
/// This function reads the output probabilities from finalLayer to CPU, sorts them and gets the label with heighest probability
/// </summary>
/// <param name="finalLayer">output image of the network this has probabilities of each digit</param>
/// <returns>Guess of the network as to what the digit is as uint</returns>
public uint GetLabel(MPSImage finalLayer)
{
// even though we have 10 labels outputed the MTLTexture format used is RGBAFloat16 thus 3 slices will have 3*4 = 12 outputs
var resultHalfArray = Enumerable.Repeat((ushort)6, 12).ToArray();
var resultHalfArrayHandle = GCHandle.Alloc(resultHalfArray, GCHandleType.Pinned);
var resultHalfArrayPtr = resultHalfArrayHandle.AddrOfPinnedObject();
var resultFloatArray = Enumerable.Repeat(0.3f, 10).ToArray();
var resultFloatArrayHandle = GCHandle.Alloc(resultFloatArray, GCHandleType.Pinned);
var resultFloatArrayPtr = resultFloatArrayHandle.AddrOfPinnedObject();
for (uint i = 0; i <= 2; i++)
{
finalLayer.Texture.GetBytes(resultHalfArrayPtr + 4 * (int)i * sizeof(ushort),
sizeof(ushort) * 1 * 4, sizeof(ushort) * 1 * 1 * 4,
new MTLRegion(new MTLOrigin(0, 0, 0), new MTLSize(1, 1, 1)),
0, i);
}
// we use vImage to convert our data to float16, Metal GPUs use float16 and swift float is 32-bit
var fullResultVImagebuf = new vImageBuffer {
Data = resultFloatArrayPtr,
Height = 1,
Width = 10,
BytesPerRow = 10 * 4
};
var halfResultVImagebuf = new vImageBuffer {
Data = resultHalfArrayPtr,
Height = 1,
Width = 10,
BytesPerRow = 10 * 2
};
if (Planar16FtoPlanarF(ref halfResultVImagebuf, ref fullResultVImagebuf, 0) != vImageError.NoError)
{
Console.WriteLine("Error in vImage");
}
// poll all labels for probability and choose the one with max probability to return
float max = 0f;
uint mostProbableDigit = 10;
for (uint i = 0; i <= 9; i++)
{
if (max < resultFloatArray [i])
{
max = resultFloatArray [i];
mostProbableDigit = i;
}
}
resultHalfArrayHandle.Free();
resultFloatArrayHandle.Free();
return(mostProbableDigit);
}
public unsafe static UIImage ApplyBlur(UIImage image, float blurRadius, UIColor tintColor, float saturationDeltaFactor, UIImage maskImage)
{
if (image.Size.Width < 1 || image.Size.Height < 1)
{
Debug.WriteLine(@"*** error: invalid size: ({0} x {1}). Both dimensions must be >= 1: {2}", image.Size.Width, image.Size.Height, image);
return(null);
}
if (image.CGImage == null)
{
Debug.WriteLine(@"*** error: image must be backed by a CGImage: {0}", image);
return(null);
}
if (maskImage != null && maskImage.CGImage == null)
{
Debug.WriteLine(@"*** error: maskImage must be backed by a CGImage: {0}", maskImage);
return(null);
}
var imageRect = new RectangleF(PointF.Empty, image.Size);
var effectImage = image;
bool hasBlur = blurRadius > float.Epsilon;
bool hasSaturationChange = Math.Abs(saturationDeltaFactor - 1) > float.Epsilon;
if (hasBlur || hasSaturationChange)
{
UIGraphics.BeginImageContextWithOptions(image.Size, false, UIScreen.MainScreen.Scale);
var contextIn = UIGraphics.GetCurrentContext();
contextIn.ScaleCTM(1.0f, -1.0f);
contextIn.TranslateCTM(0, -image.Size.Height);
contextIn.DrawImage(imageRect, image.CGImage);
var effectInContext = contextIn.AsBitmapContext() as CGBitmapContext;
var effectInBuffer = new vImageBuffer()
{
Data = effectInContext.Data,
Width = effectInContext.Width,
Height = effectInContext.Height,
BytesPerRow = effectInContext.BytesPerRow
};
UIGraphics.BeginImageContextWithOptions(image.Size, false, UIScreen.MainScreen.Scale);
var effectOutContext = UIGraphics.GetCurrentContext().AsBitmapContext() as CGBitmapContext;
var effectOutBuffer = new vImageBuffer()
{
Data = effectOutContext.Data,
Width = effectOutContext.Width,
Height = effectOutContext.Height,
BytesPerRow = effectOutContext.BytesPerRow
};
if (hasBlur)
{
var inputRadius = blurRadius * UIScreen.MainScreen.Scale;
uint radius = (uint)(Math.Floor(inputRadius * 3 * Math.Sqrt(2 * Math.PI) / 4 + 0.5));
if ((radius % 2) != 1)
{
radius += 1;
}
vImage.BoxConvolveARGB8888(ref effectInBuffer, ref effectOutBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
vImage.BoxConvolveARGB8888(ref effectOutBuffer, ref effectInBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
vImage.BoxConvolveARGB8888(ref effectInBuffer, ref effectOutBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
}
bool effectImageBuffersAreSwapped = false;
if (hasSaturationChange)
{
var s = saturationDeltaFactor;
var floatingPointSaturationMatrix = new float [] {
0.0722f + 0.9278f * s, 0.0722f - 0.0722f * s, 0.0722f - 0.0722f * s, 0,
0.7152f - 0.7152f * s, 0.7152f + 0.2848f * s, 0.7152f - 0.7152f * s, 0,
0.2126f - 0.2126f * s, 0.2126f - 0.2126f * s, 0.2126f + 0.7873f * s, 0,
0, 0, 0, 1,
};
const int divisor = 256;
var saturationMatrix = new short [floatingPointSaturationMatrix.Length];
for (int i = 0; i < saturationMatrix.Length; i++)
{
saturationMatrix [i] = (short)Math.Round(floatingPointSaturationMatrix [i] * divisor);
}
if (hasBlur)
{
vImage.MatrixMultiplyARGB8888(ref effectOutBuffer, ref effectInBuffer, saturationMatrix, divisor, null, null, vImageFlags.NoFlags);
effectImageBuffersAreSwapped = true;
}
else
{
vImage.MatrixMultiplyARGB8888(ref effectInBuffer, ref effectOutBuffer, saturationMatrix, divisor, null, null, vImageFlags.NoFlags);
}
}
if (!effectImageBuffersAreSwapped)
{
effectImage = UIGraphics.GetImageFromCurrentImageContext();
}
UIGraphics.EndImageContext();
if (effectImageBuffersAreSwapped)
{
effectImage = UIGraphics.GetImageFromCurrentImageContext();
}
UIGraphics.EndImageContext();
}
// Setup up output context
UIGraphics.BeginImageContextWithOptions(image.Size, false, UIScreen.MainScreen.Scale);
var outputContext = UIGraphics.GetCurrentContext();
outputContext.ScaleCTM(1, -1);
outputContext.TranslateCTM(0, -image.Size.Height);
// Draw base image
if (hasBlur)
{
outputContext.SaveState();
if (maskImage != null)
{
outputContext.ClipToMask(imageRect, maskImage.CGImage);
}
outputContext.DrawImage(imageRect, effectImage.CGImage);
outputContext.RestoreState();
}
if (tintColor != null)
{
outputContext.SaveState();
outputContext.SetFillColor(tintColor.CGColor);
outputContext.FillRect(imageRect);
outputContext.RestoreState();
}
var outputImage = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
return(outputImage);
}
public unsafe static UIImage ApplyBlur (UIImage image, float blurRadius, UIColor tintColor, float saturationDeltaFactor, UIImage maskImage)
{
if (image.Size.Width < 1 || image.Size.Height < 1) {
Debug.WriteLine (@"*** error: invalid size: ({0} x {1}). Both dimensions must be >= 1: {2}", image.Size.Width, image.Size.Height, image);
return null;
}
if (image.CGImage == null) {
Debug.WriteLine (@"*** error: image must be backed by a CGImage: {0}", image);
return null;
}
if (maskImage != null && maskImage.CGImage == null) {
Debug.WriteLine (@"*** error: maskImage must be backed by a CGImage: {0}", maskImage);
return null;
}
var imageRect = new RectangleF (PointF.Empty, image.Size);
var effectImage = image;
bool hasBlur = blurRadius > float.Epsilon;
bool hasSaturationChange = Math.Abs (saturationDeltaFactor - 1) > float.Epsilon;
if (hasBlur || hasSaturationChange) {
UIGraphics.BeginImageContextWithOptions (image.Size, false, UIScreen.MainScreen.Scale);
var contextIn = UIGraphics.GetCurrentContext ();
contextIn.ScaleCTM (1.0f, -1.0f);
contextIn.TranslateCTM (0, -image.Size.Height);
contextIn.DrawImage (imageRect, image.CGImage);
var effectInContext = contextIn.AsBitmapContext () as CGBitmapContext;
var effectInBuffer = new vImageBuffer () {
Data = effectInContext.Data,
Width = effectInContext.Width,
Height = effectInContext.Height,
BytesPerRow = effectInContext.BytesPerRow
};
UIGraphics.BeginImageContextWithOptions (image.Size, false, UIScreen.MainScreen.Scale);
var effectOutContext = UIGraphics.GetCurrentContext ().AsBitmapContext () as CGBitmapContext;
var effectOutBuffer = new vImageBuffer () {
Data = effectOutContext.Data,
Width = effectOutContext.Width,
Height = effectOutContext.Height,
BytesPerRow = effectOutContext.BytesPerRow
};
if (hasBlur) {
var inputRadius = blurRadius * UIScreen.MainScreen.Scale;
uint radius = (uint)(Math.Floor (inputRadius * 3 * Math.Sqrt (2 * Math.PI) / 4 + 0.5));
if ((radius % 2) != 1)
radius += 1;
vImage.BoxConvolveARGB8888 (ref effectInBuffer, ref effectOutBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
vImage.BoxConvolveARGB8888 (ref effectOutBuffer, ref effectInBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
vImage.BoxConvolveARGB8888 (ref effectInBuffer, ref effectOutBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
}
bool effectImageBuffersAreSwapped = false;
if (hasSaturationChange) {
var s = saturationDeltaFactor;
var floatingPointSaturationMatrix = new float [] {
0.0722f + 0.9278f * s, 0.0722f - 0.0722f * s, 0.0722f - 0.0722f * s, 0,
0.7152f - 0.7152f * s, 0.7152f + 0.2848f * s, 0.7152f - 0.7152f * s, 0,
0.2126f - 0.2126f * s, 0.2126f - 0.2126f * s, 0.2126f + 0.7873f * s, 0,
0, 0, 0, 1,
};
const int divisor = 256;
var saturationMatrix = new short [floatingPointSaturationMatrix.Length];
for (int i = 0; i < saturationMatrix.Length; i++)
saturationMatrix [i] = (short)Math.Round (floatingPointSaturationMatrix [i] * divisor);
if (hasBlur) {
vImage.MatrixMultiplyARGB8888 (ref effectOutBuffer, ref effectInBuffer, saturationMatrix, divisor, null, null, vImageFlags.NoFlags);
effectImageBuffersAreSwapped = true;
} else
vImage.MatrixMultiplyARGB8888 (ref effectInBuffer, ref effectOutBuffer, saturationMatrix, divisor, null, null, vImageFlags.NoFlags);
}
if (!effectImageBuffersAreSwapped)
effectImage = UIGraphics.GetImageFromCurrentImageContext ();
UIGraphics.EndImageContext ();
if (effectImageBuffersAreSwapped)
effectImage = UIGraphics.GetImageFromCurrentImageContext ();
UIGraphics.EndImageContext ();
}
// Setup up output context
UIGraphics.BeginImageContextWithOptions (image.Size, false, UIScreen.MainScreen.Scale);
var outputContext = UIGraphics.GetCurrentContext ();
outputContext.ScaleCTM (1, -1);
outputContext.TranslateCTM (0, -image.Size.Height);
// Draw base image
if (hasBlur) {
outputContext.SaveState ();
if (maskImage != null)
outputContext.ClipToMask (imageRect, maskImage.CGImage);
outputContext.DrawImage (imageRect, effectImage.CGImage);
outputContext.RestoreState ();
}
if (tintColor != null) {
outputContext.SaveState ();
outputContext.SetFillColor (tintColor.CGColor);
outputContext.FillRect (imageRect);
outputContext.RestoreState ();
}
var outputImage = UIGraphics.GetImageFromCurrentImageContext ();
UIGraphics.EndImageContext ();
return outputImage;
}
unsafe public static vImageError Planar16FtoPlanarF(ref vImageBuffer src, ref vImageBuffer dest, vImageFlags flags)
{
return((vImageError)(long)vImageConvert_Planar16FtoPlanarF(ref src, ref dest, flags));
}
extern static nint vImageConvert_Planar16FtoPlanarF(ref vImageBuffer src, ref vImageBuffer dest, vImageFlags flags);
/// <summary>
/// Internal method to create a blurred image since this has to run on the main thread.
/// </summary>
/// <returns>The blurred image.</returns>
/// <param name="image">Image to be blurred.</param>
/// <param name="blurRadius">Blur radius.</param>
/// <remarks>
/// Originally from: https://github.com/xamarin/ios-samples/blob/master/UIImageEffects/UIImageEffects.cs
/// </remarks>
private static UIImage InternalCreateBlurredImage(UIImage image, float blurRadius)
{
var imageRect = new CGRect(CGPoint.Empty, image.Size);
var effectImage = image;
UIGraphics.BeginImageContextWithOptions(image.Size, false, UIScreen.MainScreen.Scale);
var contextIn = UIGraphics.GetCurrentContext();
contextIn.ScaleCTM(1.0f, -1.0f);
contextIn.TranslateCTM(0, -image.Size.Height);
contextIn.DrawImage(imageRect, image.CGImage);
var effectInContext = contextIn.AsBitmapContext() as CGBitmapContext;
var effectInBuffer = new vImageBuffer()
{
Data = effectInContext.Data,
Width = ( int )effectInContext.Width,
Height = ( int )effectInContext.Height,
BytesPerRow = ( int )effectInContext.BytesPerRow
};
UIGraphics.BeginImageContextWithOptions(image.Size, false, UIScreen.MainScreen.Scale);
var effectOutContext = UIGraphics.GetCurrentContext().AsBitmapContext() as CGBitmapContext;
var effectOutBuffer = new vImageBuffer()
{
Data = effectOutContext.Data,
Width = ( int )effectOutContext.Width,
Height = ( int )effectOutContext.Height,
BytesPerRow = ( int )effectOutContext.BytesPerRow
};
var inputRadius = blurRadius * UIScreen.MainScreen.Scale / 2.0f;
uint radius = ( uint )(Math.Floor(inputRadius * 3 * Math.Sqrt(2 * Math.PI) / 4 + 0.5));
if ((radius % 2) != 1)
{
radius += 1;
}
vImage.BoxConvolveARGB8888(ref effectInBuffer, ref effectOutBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
vImage.BoxConvolveARGB8888(ref effectOutBuffer, ref effectInBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
vImage.BoxConvolveARGB8888(ref effectInBuffer, ref effectOutBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
effectImage = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
UIGraphics.EndImageContext();
// Setup up output context
UIGraphics.BeginImageContextWithOptions(image.Size, false, UIScreen.MainScreen.Scale);
var outputContext = UIGraphics.GetCurrentContext();
outputContext.ScaleCTM(1, -1);
outputContext.TranslateCTM(0, -image.Size.Height);
// Draw base image
outputContext.SaveState();
outputContext.DrawImage(imageRect, effectImage.CGImage);
outputContext.RestoreState();
var outputImage = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
return(outputImage);
}
/// <summary>
/// Applies the blur with radius.
/// </summary>
/// <returns>The blur with radius.</returns>
/// <param name="target">Target.</param>
/// <param name="blurRadius">Blur radius.</param>
/// <param name="tintColor">Tint color.</param>
/// <param name="saturationDeltaFactor">Saturation delta factor.</param>
/// <param name="maskImage">Mask image.</param>
public static UIImage ApplyBlurWithRadius(this UIImage target, nfloat blurRadius, UIColor tintColor, nfloat saturationDeltaFactor, UIImage maskImage)
{
// Check pre-conditions.
if (target.Size.Width < 1 || target.Size.Height < 1)
{
throw new Exception(String.Format(@"*** error: invalid size: (%.2 x %.2f). Both dimensions must be >= 1: %@", target.Size.Width, target.Size.Height, target));
}
if (target.CGImage == null)
{
throw new Exception(String.Format(@"*** error: image must be backed by a CGImage: %@", target));
}
if (maskImage != null &&
maskImage.CGImage == null)
{
throw new Exception(String.Format(@"*** error: maskImage must be backed by a CGImage: %@", maskImage));
}
//
var imageRect = new CGRect(CGPoint.Empty, target.Size);
var effectImage = target;
//
bool hasBlur = blurRadius > float.Epsilon;
bool hasSaturationChange = Math.Abs(saturationDeltaFactor - 1d) > float.Epsilon;
if (hasBlur || hasSaturationChange)
{
UIGraphics.BeginImageContextWithOptions(target.Size, false, UIScreen.MainScreen.Scale);
var effectInContext = UIGraphics.GetCurrentContext();
effectInContext.ScaleCTM(1.0f, -1.0f);
effectInContext.TranslateCTM(0, -target.Size.Height);
effectInContext.DrawImage(imageRect, target.CGImage);
var gctx = effectInContext.AsBitmapContext();
vImageBuffer effectInBuffer = new vImageBuffer();
effectInBuffer.Data = gctx.Data;
effectInBuffer.Width = (int)gctx.Width;
effectInBuffer.Height = (int)gctx.Height;
effectInBuffer.BytesPerRow = (int)gctx.BytesPerRow;
UIGraphics.BeginImageContextWithOptions(target.Size, false, UIScreen.MainScreen.Scale);
var effectOutContext = UIGraphics.GetCurrentContext();
var gctxOut = effectOutContext.AsBitmapContext();
vImageBuffer effectOutBuffer = new vImageBuffer();
effectOutBuffer.Data = gctxOut.Data;
effectOutBuffer.Width = (int)gctxOut.Width;
effectOutBuffer.Height = (int)gctxOut.Height;
effectOutBuffer.BytesPerRow = (int)gctxOut.BytesPerRow;
if (hasBlur)
{
// A description of how to compute the box kernel width from the Gaussian
// radius (aka standard deviation) appears in the SVG spec:
// http://www.w3.org/TR/SVG/filters.html#feGaussianBlurElement
//
// For larger values of 's' (s >= 2.0), an approximation can be used: Three
// successive box-blurs build a piece-wise quadratic convolution kernel, which
// approximates the Gaussian kernel to within roughly 3%.
//
// let d = floor(s * 3*sqrt(2*pi)/4 + 0.5)
//
// ... if d is odd, use three box-blurs of size 'd', centered on the output pixel.
//
var inputRadius = blurRadius * UIScreen.MainScreen.Scale;
var radius = (uint)Math.Floor(inputRadius * 3f * Math.Sqrt(2 * Math.PI) / 4 + 0.5);
if (radius % 2 != 1)
{
radius += 1; // force radius to be odd so that the three box-blur methodology works.
}
vImage.BoxConvolveARGB8888(ref effectInBuffer, ref effectOutBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
vImage.BoxConvolveARGB8888(ref effectOutBuffer, ref effectInBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
vImage.BoxConvolveARGB8888(ref effectInBuffer, ref effectOutBuffer, IntPtr.Zero, 0, 0, radius, radius, Pixel8888.Zero, vImageFlags.EdgeExtend);
}
bool effectImageBuffersAreSwapped = false;
if (hasSaturationChange)
{
var s = saturationDeltaFactor;
var floatingPointSaturationMatrix = new nfloat[] {
0.0722f + 0.9278f * s, 0.0722f - 0.0722f * s, 0.0722f - 0.0722f * s, 0f,
0.7152f - 0.7152f * s, 0.7152f + 0.2848f * s, 0.7152f - 0.7152f * s, 0f,
0.2126f - 0.2126f * s, 0.2126f - 0.2126f * s, 0.2126f + 0.7873f * s, 0f,
0f, 0f, 0f, 1f,
};
var divisor = 256;
var matrixSize = floatingPointSaturationMatrix.Length / sizeof(float);
var saturationMatrix = new short[matrixSize];
for (int i = 0; i < matrixSize; ++i)
{
saturationMatrix[i] = (short)Math.Round(floatingPointSaturationMatrix[i] * divisor);
}
if (hasBlur)
{
vImage.MatrixMultiplyARGB8888(ref effectOutBuffer, ref effectInBuffer, saturationMatrix, divisor, null, null, vImageFlags.NoFlags);
effectImageBuffersAreSwapped = true;
}
else
{
vImage.MatrixMultiplyARGB8888(ref effectInBuffer, ref effectOutBuffer, saturationMatrix, divisor, null, null, vImageFlags.NoFlags);
}
}
if (!effectImageBuffersAreSwapped)
{
effectImage = UIGraphics.GetImageFromCurrentImageContext();
}
UIGraphics.EndImageContext();
if (effectImageBuffersAreSwapped)
{
effectImage = UIGraphics.GetImageFromCurrentImageContext();
}
UIGraphics.EndImageContext();
}
// Set up output context.
UIGraphics.BeginImageContextWithOptions(target.Size, false, UIScreen.MainScreen.Scale);
var outputContext = UIGraphics.GetCurrentContext();
outputContext.ScaleCTM(1.0f, -1.0f);
outputContext.TranslateCTM(0, -target.Size.Height);
// Draw base image.
outputContext.DrawImage(imageRect, target.CGImage);
// Draw effect image.
if (hasBlur)
{
outputContext.SaveState();
if (maskImage != null)
{
outputContext.ClipToMask(imageRect, maskImage.CGImage);
}
outputContext.DrawImage(imageRect, effectImage.CGImage);
outputContext.RestoreState();
}
// Add in color tint.
if (tintColor != null)
{
outputContext.SaveState();
outputContext.SetFillColor(tintColor.CGColor);
outputContext.FillRect(imageRect);
outputContext.RestoreState();
}
UIImage outputImage = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
//
return(outputImage);
}
unsafe public static vImageError Planar16FtoPlanarF (ref vImageBuffer src, ref vImageBuffer dest, vImageFlags flags)
{
return (vImageError)(long)vImageConvert_Planar16FtoPlanarF (ref src, ref dest, flags);
}
extern static nint vImageConvert_Planar16FtoPlanarF (ref vImageBuffer src, ref vImageBuffer dest, vImageFlags flags);
/// <summary>
/// This function reads the output probabilities from finalLayer to CPU, sorts them and gets the label with heighest probability
/// </summary>
/// <param name="finalLayer">output image of the network this has probabilities of each digit</param>
/// <returns>Guess of the network as to what the digit is as uint</returns>
public uint GetLabel (MPSImage finalLayer)
{
// even though we have 10 labels outputed the MTLTexture format used is RGBAFloat16 thus 3 slices will have 3*4 = 12 outputs
var resultHalfArray = Enumerable.Repeat ((ushort)6, 12).ToArray ();
var resultHalfArrayHandle = GCHandle.Alloc (resultHalfArray, GCHandleType.Pinned);
var resultHalfArrayPtr = resultHalfArrayHandle.AddrOfPinnedObject ();
var resultFloatArray = Enumerable.Repeat (0.3f, 10).ToArray ();
var resultFloatArrayHandle = GCHandle.Alloc (resultFloatArray, GCHandleType.Pinned);
var resultFloatArrayPtr = resultFloatArrayHandle.AddrOfPinnedObject ();
for (uint i = 0; i <= 2; i++) {
finalLayer.Texture.GetBytes (resultHalfArrayPtr + 4 * (int)i * sizeof (ushort),
sizeof (ushort) * 1 * 4, sizeof (ushort) * 1 * 1 * 4,
new MTLRegion (new MTLOrigin (0, 0, 0), new MTLSize (1, 1, 1)),
0, i);
}
// we use vImage to convert our data to float16, Metal GPUs use float16 and swift float is 32-bit
var fullResultVImagebuf = new vImageBuffer {
Data = resultFloatArrayPtr,
Height = 1,
Width = 10,
BytesPerRow = 10 * 4
};
var halfResultVImagebuf = new vImageBuffer {
Data = resultHalfArrayPtr,
Height = 1,
Width = 10,
BytesPerRow = 10 * 2
};
if (Planar16FtoPlanarF (ref halfResultVImagebuf, ref fullResultVImagebuf, 0) != vImageError.NoError)
Console.WriteLine ("Error in vImage");
// poll all labels for probability and choose the one with max probability to return
float max = 0f;
uint mostProbableDigit = 10;
for (uint i = 0; i <= 9; i++) {
if (max < resultFloatArray [i]) {
max = resultFloatArray [i];
mostProbableDigit = i;
}
}
resultHalfArrayHandle.Free ();
resultFloatArrayHandle.Free ();
return mostProbableDigit;
}