1 using System;
2 using System.Threading.Tasks;
3 using System.Runtime.InteropServices.WindowsRuntime;
4 using Windows.Graphics.Imaging;
5 using Windows.UI.Xaml.Media.Imaging;
6 using Windows.Storage;
7 using Windows.Storage.Pickers;
8 using Windows.Storage.Streams;
9 using System.IO;
10 using Windows.Foundation;
11 using System.Collections.Generic;
12
13 namespace Common
14 {
15 public class ImageHelper
16 {
17 public const int THumbLength = 400;
18 public static Size MinSizeSupported = new Size(200, 200);
19 public static Size MaxSizeSupported = new Size(4000, 3000);
20
21 static Guid EncoderIDFromFileExtension(string strExtension)
22 {
23 Guid encoderId;
24 switch (strExtension.ToLower())
25 {
26 case ".jpg":
27 case ".jpeg":
28 encoderId = BitmapEncoder.JpegEncoderId;
29 break;
30 case ".bmp":
31 encoderId = BitmapEncoder.BmpEncoderId;
32 break;
33 case ".png":
34 default:
35 encoderId = BitmapEncoder.PngEncoderId;
36 break;
37 }
38 return encoderId;
39 }
40 static Guid DecoderIDFromFileExtension(string strExtension)
41 {
42 Guid encoderId;
43 switch (strExtension.ToLower())
44 {
45 case ".jpg":
46 case ".jpeg":
47 encoderId = BitmapDecoder.JpegDecoderId;
48 break;
49 case ".bmp":
50 encoderId = BitmapDecoder.BmpDecoderId;
51 break;
52 case ".png":
53 default:
54 encoderId = BitmapDecoder.PngDecoderId;
55 break;
56 }
57 return encoderId;
58 }
59
60 public async static Task<WriteableBitmap> ReadBitmap(IRandomAccessStream fileStream, string type)
61 {
62 WriteableBitmap bitmap = null;
63 try
64 {
65 Guid decoderId = DecoderIDFromFileExtension(type);
66
67 BitmapDecoder decoder = await BitmapDecoder.CreateAsync(decoderId, fileStream);
68 BitmapTransform tf = new BitmapTransform();
69
70 uint width = decoder.OrientedPixelWidth;
71 uint height = decoder.OrientedPixelHeight;
72 double dScale = 1;
73
74 if (decoder.OrientedPixelWidth > MaxSizeSupported.Width || decoder.OrientedPixelHeight > MaxSizeSupported.Height)
75 {
76 dScale = Math.Min(MaxSizeSupported.Width / decoder.OrientedPixelWidth, MaxSizeSupported.Height/decoder.OrientedPixelHeight );
77 width =(uint)( decoder.OrientedPixelWidth * dScale);
78 height = (uint)(decoder.OrientedPixelHeight * dScale);
79
80 tf.ScaledWidth = (uint)(decoder.PixelWidth* dScale);
81 tf.ScaledHeight = (uint)(decoder.PixelHeight* dScale);
82 }
83
84
85 bitmap = new WriteableBitmap((int)width, (int)height);
86
87
88
89 PixelDataProvider dataprovider = await decoder.GetPixelDataAsync(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Straight, tf,
90 ExifOrientationMode.RespectExifOrientation, ColorManagementMode.DoNotColorManage);
91 byte[] pixels = dataprovider.DetachPixelData();
92
93 Stream pixelStream2 = bitmap.PixelBuffer.AsStream();
94
95 pixelStream2.Write(pixels, 0, pixels.Length);
96 //bitmap.SetSource(fileStream);
97 }
98 catch
99 {
100 }
101
102 return bitmap;
103 }
104
105 public async static Task<WriteableBitmap> ReadBitmap(StorageFile file)
106 {
107 IRandomAccessStream stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
108 WriteableBitmap bitmap = await ReadBitmap(stream, file.FileType.ToLower());
109
110 return bitmap;
111 }
112
113
114 public async static Task<bool> SaveBitmap(IRandomAccessStream stream, Guid encoderId, WriteableBitmap bitmap, BitmapTransform bitmapTransform)
115 {
116 bool bSuccess = true;
117 try
118 {
119 Stream pixelStream = bitmap.PixelBuffer.AsStream();
120
121 BitmapEncoder encoder = await BitmapEncoder.CreateAsync(encoderId, stream);
122 if (bitmapTransform != null)
123 {
124 encoder.BitmapTransform.ScaledWidth = bitmapTransform.ScaledWidth;
125 encoder.BitmapTransform.ScaledHeight = bitmapTransform.ScaledHeight;
126 encoder.BitmapTransform.InterpolationMode = BitmapInterpolationMode.Fant;
127 encoder.BitmapTransform.Bounds = bitmapTransform.Bounds;
128 }
129
130 byte[] pixels = new byte[pixelStream.Length];
131
132 pixelStream.Read(pixels, 0, pixels.Length);
133
134 encoder.SetPixelData(
135 BitmapPixelFormat.Bgra8,
136 BitmapAlphaMode.Straight,
137 (uint)bitmap.PixelWidth,
138 (uint)bitmap.PixelHeight,
139 96, // Horizontal DPI
140 96, // Vertical DPI
141 pixels
142 );
143 await encoder.FlushAsync();
144
145 pixelStream.Dispose();
146 }
147 catch
148 {
149 bSuccess = false;
150 }
151
152 return bSuccess;
153 }
154
155 async static Task<bool> SaveBitmap(StorageFile file, WriteableBitmap bitmap, BitmapTransform bitmapTransform)
156 {
157 bool bSuccess = true;
158 try
159 {
160 // Application now has read/write access to the saved file
161 Guid encoderId = EncoderIDFromFileExtension(file.FileType);
162
163
164 IRandomAccessStream fileStream = await file.OpenAsync(Windows.Storage.FileAccessMode.ReadWrite);
165
166 bSuccess = await SaveBitmap(fileStream, encoderId,bitmap,bitmapTransform);
167
168 fileStream.Dispose();
169
170 }
171 catch
172 {
173 bSuccess = false;
174 }
175
176 return bSuccess;
177 }
178
179 public async static Task<bool> SaveBitmap(StorageFile file, WriteableBitmap bitmap)
180 {
181 bool bSuccess = await SaveBitmap(file, bitmap, null);
182 return bSuccess;
183 }
184
185 public async static Task<bool> SaveBitmapWithFilePicker(WriteableBitmap bitmap)
186 {
187 FileSavePicker save = new FileSavePicker();
188 save.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
189 save.DefaultFileExtension = ".jpg";
190 save.SuggestedFileName = "new image";
191 save.FileTypeChoices.Add(".bmp", new List<string>() { ".bmp" });
192 save.FileTypeChoices.Add(".png", new List<string>() { ".png" });
193 save.FileTypeChoices.Add(".jpg", new List<string>() { ".jpg", ".jpeg" });
194
195 StorageFile savedItem = await save.PickSaveFileAsync();
196 if (savedItem == null)
197 {
198 return false;
199 }
200
201 return await SaveBitmap(savedItem, bitmap);
202 }
203
204 public async static Task<bool> SaveBitmapAsThumb(StorageFile file, WriteableBitmap bitmap, double width, double height)
205 {
206 BitmapTransform transform = new BitmapTransform();
207
208 double ratio = Math.Min(width / bitmap.PixelWidth, height / bitmap.PixelHeight);
209
210 transform.ScaledWidth = (uint)(bitmap.PixelWidth * ratio);
211 transform.ScaledHeight = (uint)(bitmap.PixelHeight * ratio);
212 transform.InterpolationMode = BitmapInterpolationMode.Fant;
213
214 return await SaveBitmap(file, bitmap, transform);
215 }
216 public async static Task<bool> SaveBitmapAsThumb(StorageFile file, WriteableBitmap bitmap, Windows.Foundation.Rect cropRect)
217 {
218 BitmapTransform transform = new BitmapTransform();
219
220
221 double ratio =THumbLength/ Math.Max(cropRect.Width, cropRect.Height );
222
223 transform.ScaledWidth = (uint)(bitmap.PixelWidth * ratio);
224 transform.ScaledHeight = (uint)(bitmap.PixelHeight * ratio);
225 transform.Bounds = new BitmapBounds()
226 {
227 X = (uint)(cropRect.X * ratio),
228 Y = (uint)(cropRect.Y * ratio),
229 Width = (uint)(cropRect.Width * ratio),
230 Height = (uint)(cropRect.Height * ratio)
231 };
232 transform.InterpolationMode = BitmapInterpolationMode.Fant;
233
234 return await SaveBitmap(file, bitmap, transform);
235 }
236 }
237 }
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