ImageEstimatorsCatalog.ExtractPixels Yöntem
Tanım
Önemli
Bazı bilgiler ürünün ön sürümüyle ilgilidir ve sürüm öncesinde önemli değişiklikler yapılmış olabilir. Burada verilen bilgilerle ilgili olarak Microsoft açık veya zımni hiçbir garanti vermez.
sütunda belirtilen verilerden piksel değerlerini yeni bir sütuna ayıklayan bir ImagePixelExtractingEstimatoroluşturun: inputColumnName
outputColumnName
.
public static Microsoft.ML.Transforms.Image.ImagePixelExtractingEstimator ExtractPixels (this Microsoft.ML.TransformsCatalog catalog, string outputColumnName, string inputColumnName = default, Microsoft.ML.Transforms.Image.ImagePixelExtractingEstimator.ColorBits colorsToExtract = Microsoft.ML.Transforms.Image.ImagePixelExtractingEstimator+ColorBits.Rgb, Microsoft.ML.Transforms.Image.ImagePixelExtractingEstimator.ColorsOrder orderOfExtraction = Microsoft.ML.Transforms.Image.ImagePixelExtractingEstimator+ColorsOrder.ARGB, bool interleavePixelColors = false, float offsetImage = 0, float scaleImage = 1, bool outputAsFloatArray = true);
static member ExtractPixels : Microsoft.ML.TransformsCatalog * string * string * Microsoft.ML.Transforms.Image.ImagePixelExtractingEstimator.ColorBits * Microsoft.ML.Transforms.Image.ImagePixelExtractingEstimator.ColorsOrder * bool * single * single * bool -> Microsoft.ML.Transforms.Image.ImagePixelExtractingEstimator
<Extension()>
Public Function ExtractPixels (catalog As TransformsCatalog, outputColumnName As String, Optional inputColumnName As String = Nothing, Optional colorsToExtract As ImagePixelExtractingEstimator.ColorBits = Microsoft.ML.Transforms.Image.ImagePixelExtractingEstimator+ColorBits.Rgb, Optional orderOfExtraction As ImagePixelExtractingEstimator.ColorsOrder = Microsoft.ML.Transforms.Image.ImagePixelExtractingEstimator+ColorsOrder.ARGB, Optional interleavePixelColors As Boolean = false, Optional offsetImage As Single = 0, Optional scaleImage As Single = 1, Optional outputAsFloatArray As Boolean = true) As ImagePixelExtractingEstimator
Parametreler
- catalog
- TransformsCatalog
Dönüşümün kataloğu.
- outputColumnName
- String
dönüştürmesinden kaynaklanan sütunun inputColumnName
adı.
Bu sütunun veri türü, veya Byte öğesine bağlı outputAsFloatArray
olarak bilinen boyutlu bir vektör Single olacaktır.
- colorsToExtract
- ImagePixelExtractingEstimator.ColorBits
Görüntüden ayıklanan renkler.
- orderOfExtraction
- ImagePixelExtractingEstimator.ColorsOrder
Pikselden renkleri ayıklama sırası.
- interleavePixelColors
- Boolean
Piksel renklerini birbirine ayırma, yani bunları sıralı orderOfExtraction
tutma veya planlayıcı formunda bırakma: tüm pikseller için bir rengin tüm değerleri, ardından başka bir rengin tüm değerleri vb.
- offsetImage
- Single
Her pikselin renk değerini bu miktara göre kaydır. öncesinde scaleImage
renk değerine uygulanır.
- scaleImage
- Single
Her pikselin renk değerini bu miktara göre ölçeklendirin. sonrasındaki offsetImage
renk değerine uygulanır.
- outputAsFloatArray
- Boolean
Diziyi float dizisi olarak çıktı. False ise bayt dizisi olarak çıkış yapın ve ve scaleImage
değerlerini offsetImage
yoksayar.
Döndürülenler
Örnekler
using System;
using System.IO;
using System.Linq;
using Microsoft.ML;
using Microsoft.ML.Data;
namespace Samples.Dynamic
{
public static class ExtractPixels
{
// Sample that loads the images from the file system, resizes them (
// ExtractPixels requires a resizing operation), and extracts the values of
// the pixels as a vector.
public static void Example()
{
// Create a new ML context, for ML.NET operations. It can be used for
// exception tracking and logging, as well as the source of randomness.
var mlContext = new MLContext();
// Downloading a few images, and an images.tsv file, which contains a
// list of the files from the dotnet/machinelearning/test/data/images/.
// If you inspect the fileSystem, after running this line, an "images"
// folder will be created, containing 4 images, and a .tsv file
// enumerating the images.
var imagesDataFile = Microsoft.ML.SamplesUtils.DatasetUtils
.GetSampleImages();
// Preview of the content of the images.tsv file
//
// imagePath imageType
// tomato.bmp tomato
// banana.jpg banana
// hotdog.jpg hotdog
// tomato.jpg tomato
var data = mlContext.Data.CreateTextLoader(new TextLoader.Options()
{
Columns = new[]
{
new TextLoader.Column("ImagePath", DataKind.String, 0),
new TextLoader.Column("Name", DataKind.String, 1),
}
}).Load(imagesDataFile);
var imagesFolder = Path.GetDirectoryName(imagesDataFile);
// Image loading pipeline.
var pipeline = mlContext.Transforms.LoadImages("ImageObject",
imagesFolder, "ImagePath")
.Append(mlContext.Transforms.ResizeImages("ImageObjectResized",
inputColumnName: "ImageObject", imageWidth: 100, imageHeight:
100))
.Append(mlContext.Transforms.ExtractPixels("Pixels",
"ImageObjectResized"));
var transformedData = pipeline.Fit(data).Transform(data);
// Preview the transformedData.
PrintColumns(transformedData);
// ImagePath Name ImageObject ImageObjectResized Pixels
// tomato.bmp tomato {Width=800, Height=534} {Width=100, Height=100} 255,255,255,255,255...
// banana.jpg banana {Width=800, Height=288} {Width=100, Height=100} 255,255,255,255,255...
// hotdog.jpg hotdog {Width=800, Height=391} {Width=100, Height=100} 255,255,255,255,255...
// tomato.jpg tomato {Width=800, Height=534} {Width=100, Height=100} 255,255,255,255,255...
}
private static void PrintColumns(IDataView transformedData)
{
Console.WriteLine("{0, -25} {1, -25} {2, -25} {3, -25} {4, -25}",
"ImagePath", "Name", "ImageObject", "ImageObjectResized", "Pixels");
using (var cursor = transformedData.GetRowCursor(transformedData
.Schema))
{
// Note that it is best to get the getters and values *before*
// iteration, so as to facilitate buffer sharing (if applicable), and
// column -type validation once, rather than many times.
ReadOnlyMemory<char> imagePath = default;
ReadOnlyMemory<char> name = default;
MLImage imageObject = null;
MLImage resizedImageObject = null;
VBuffer<float> pixels = default;
var imagePathGetter = cursor.GetGetter<ReadOnlyMemory<char>>(cursor
.Schema["ImagePath"]);
var nameGetter = cursor.GetGetter<ReadOnlyMemory<char>>(cursor
.Schema["Name"]);
var imageObjectGetter = cursor.GetGetter<MLImage>(cursor.Schema[
"ImageObject"]);
var resizedImageGetter = cursor.GetGetter<MLImage>(cursor.Schema[
"ImageObjectResized"]);
var pixelsGetter = cursor.GetGetter<VBuffer<float>>(cursor.Schema[
"Pixels"]);
while (cursor.MoveNext())
{
imagePathGetter(ref imagePath);
nameGetter(ref name);
imageObjectGetter(ref imageObject);
resizedImageGetter(ref resizedImageObject);
pixelsGetter(ref pixels);
Console.WriteLine("{0, -25} {1, -25} {2, -25} {3, -25} " +
"{4, -25}", imagePath, name,
$"Width={imageObject.Width}, Height={imageObject.Height}",
$"Width={resizedImageObject.Width}, Height={resizedImageObject.Height}",
string.Join(",", pixels.DenseValues().Take(5)) + "...");
}
// Dispose the image.
imageObject.Dispose();
resizedImageObject.Dispose();
}
}
}
}
using System;
using System.Linq;
using Microsoft.ML;
using Microsoft.ML.Data;
using Microsoft.ML.Transforms.Image;
namespace Samples.Dynamic
{
public static class ApplyOnnxModelWithInMemoryImages
{
// Example of applying ONNX transform on in-memory images.
public static void Example()
{
// Download the squeeznet image model from ONNX model zoo, version 1.2
// https://github.com/onnx/models/tree/master/vision/classification/squeezenet or use
// Microsoft.ML.Onnx.TestModels nuget.
// It's a multiclass classifier. It consumes an input "data_0" and
// produces an output "softmaxout_1".
var modelPath = @"squeezenet\00000001\model.onnx";
// Create ML pipeline to score the data using OnnxScoringEstimator
var mlContext = new MLContext();
// Create in-memory data points. Its Image/Scores field is the
// input /output of the used ONNX model.
var dataPoints = new ImageDataPoint[]
{
new ImageDataPoint(red: 255, green: 0, blue: 0), // Red color
new ImageDataPoint(red: 0, green: 128, blue: 0) // Green color
};
// Convert training data to IDataView, the general data type used in
// ML.NET.
var dataView = mlContext.Data.LoadFromEnumerable(dataPoints);
// Create a ML.NET pipeline which contains two steps. First,
// ExtractPixle is used to convert the 224x224 image to a 3x224x224
// float tensor. Then the float tensor is fed into a ONNX model with an
// input called "data_0" and an output called "softmaxout_1". Note that
// "data_0" and "softmaxout_1" are model input and output names stored
// in the used ONNX model file. Users may need to inspect their own
// models to get the right input and output column names.
// Map column "Image" to column "data_0"
// Map column "data_0" to column "softmaxout_1"
var pipeline = mlContext.Transforms.ExtractPixels("data_0", "Image")
.Append(mlContext.Transforms.ApplyOnnxModel("softmaxout_1",
"data_0", modelPath));
var model = pipeline.Fit(dataView);
var onnx = model.Transform(dataView);
// Convert IDataView back to IEnumerable<ImageDataPoint> so that user
// can inspect the output, column "softmaxout_1", of the ONNX transform.
// Note that Column "softmaxout_1" would be stored in ImageDataPont
//.Scores because the added attributed [ColumnName("softmaxout_1")]
// tells that ImageDataPont.Scores is equivalent to column
// "softmaxout_1".
var transformedDataPoints = mlContext.Data.CreateEnumerable<
ImageDataPoint>(onnx, false).ToList();
// The scores are probabilities of all possible classes, so they should
// all be positive.
foreach (var dataPoint in transformedDataPoints)
{
var firstClassProb = dataPoint.Scores.First();
var lastClassProb = dataPoint.Scores.Last();
Console.WriteLine("The probability of being the first class is " +
(firstClassProb * 100) + "%.");
Console.WriteLine($"The probability of being the last class is " +
(lastClassProb * 100) + "%.");
}
// Expected output:
// The probability of being the first class is 0.002542659%.
// The probability of being the last class is 0.0292684%.
// The probability of being the first class is 0.02258059%.
// The probability of being the last class is 0.394428%.
}
// This class is used in Example() to describe data points which will be
// consumed by ML.NET pipeline.
private class ImageDataPoint
{
// Height of Image.
private const int height = 224;
// Width of Image.
private const int width = 224;
// Image will be consumed by ONNX image multiclass classification model.
[ImageType(height, width)]
public MLImage Image { get; set; }
// Expected output of ONNX model. It contains probabilities of all
// classes. Note that the ColumnName below should match the output name
// in the used ONNX model file.
[ColumnName("softmaxout_1")]
public float[] Scores { get; set; }
public ImageDataPoint()
{
Image = null;
}
public ImageDataPoint(byte red, byte green, byte blue)
{
byte[] imageData = new byte[width * height * 4]; // 4 for the red, green, blue and alpha colors
for (int i = 0; i < imageData.Length; i += 4)
{
// Fill the buffer with the Bgra32 format
imageData[i] = blue;
imageData[i + 1] = green;
imageData[i + 2] = red;
imageData[i + 3] = 255;
}
Image = MLImage.CreateFromPixels(width, height, MLPixelFormat.Bgra32, imageData);
}
}
}
}