blocks|key|499852|text|对于4.3版本，请使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|499853|var+bmp+=+new+Bitmap(width,+height,+PixelFormat.Format32bppArgb);
Image<Bgr,+Byte>+img1+=+bmp.ToImage<Bgr,+byte>();|code-block|syntax|javascript|499854|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

For Version 4.3, use: 

<pre><code>var bmp = new Bitmap(width, height, PixelFormat.Format32bppArgb);
Image&lt;Bgr, Byte&gt; img1 = bmp.ToImage&lt;Bgr, byte&gt;();
</code></pre>

blocks|key|499833|text|您确定从eventArgs获得的帧实际上是位图吗？仅仅是因为你把它作为这样的，它没有被转换为一个，如果它没有。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|499834|试着使用：|499835|eventArgs.Frame.Clone()+as+Bitmap|code-block|syntax|javascript|499836|检查它是否为空。|499837|此外，请张贴框架抓取方法，以供参考。|499838|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Are you sure the frame you get from eventArgs is actually a bitmap? Just because you cast it as such it is not converted to one if its not.

Try using:

<pre><code>eventArgs.Frame.Clone() as Bitmap
</code></pre>

and check it for null.

Also, please post the Frame grabbing method for reference.

blocks|key|1131773|text|下面的代码降级为EmguCV+4.1.1.3497！|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1131774|entityMap|0|LINK|mutability|MUTABLE|url|https://www.nuget.org/packages/Emgu.CV/4.1.1.3497^0|8|H|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

Downgrade to <a href="https://www.nuget.org/packages/Emgu.CV/4.1.1.3497" rel="nofollow noreferrer">EmguCV 4.1.1.3497</a> for the following code!

blocks|key|499871|text|在使用最新的库(4.4.0.4099)之后，我也遇到了同样的问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|499872|以下是我为解决我的问题而不是降级所做的事情。|499873|//+Create+The+Bitmap+Object+From+EventArgs.
using+(Bitmap+bitmap+=+(Bitmap)eventArgs.Frame.Clone())
{
++++//+Define+A+File+Path.
++++string+filePath+=+Path.Combine(Path.GetTempPath(),+DateTime.Now.ToString("ddmmyyyyhhmmssfff")+%2B+".jpg");

++++//+Lock+The+Bits+In+Memory.
++++BitmapData+bitmapData+=+bitmap.LockBits(new+Rectangle(0,+0,+bitmap.Width,+bitmap.Height),+ImageLockMode.ReadOnly,+bitmap.PixelFormat);

++++//+Create+OpenCV+Image<TColor,TDepth>+Object+And+Add+The+bitmapData+Properties+Like+So.
++++using+(Image<Bgr,+byte>+grayImage+=+new+Image<Bgr,+byte>(bitmap.Width,+bitmap.Height,+bitmapData.Stride,+bitmapData.Scan0))
++++{
++++++++//+Get+The+Rectangles+That+Should+Be+Detected+From+The+Training+Data.
++++++++Rectangle[]+rectangles+=+CascadeClassifier.DetectMultiScale(image:+grayImage,+scaleFactor:+1.2,+minNeighbors:+1);

++++++++//+Unlock+The+Bits+So+We+Can+Draw+To+It.
++++++++bitmap.UnlockBits(bitmapData);

++++++++//+Loop+Each+Rectange+In+The+Retanges+Collection.
++++++++foreach+(Rectangle+rectangle+in+rectangles)
++++++++{
++++++++++++//+Create+Graphics+Object+And+Load+The+Bitmap+From+The+Beginning
++++++++++++using+(Graphics+graphics+=+Graphics.FromImage(bitmap))

++++++++++++//+Create+A+Pen,+Choose+Any+Colour
++++++++++++using+(Pen+pen+=+new+Pen(Brushes.Red))
++++++++++++{
++++++++++++++++//+Draw+The+Rectange+Onto+The+Bitmap.
++++++++++++++++graphics.DrawRectangle(pen,+rectangle);
++++++++++++}
++++++++}

++++++++//+Create+A+File+Stream+And+Save+The+Modified+Bitmap
++++++++//+We're+Using+The+Above+FilePath.
++++++++using+(FileStream+fs+=+new+FileStream(filePath,+FileMode.Create,+FileAccess.ReadWrite))
++++++++{
++++++++++++bitmap.Save(fs,+System.Drawing.Imaging.ImageFormat.Jpeg);
++++++++}
++++}

++++//+Open+The+Saved+Image+That+Should+Contain+The+Drawn+Rectangle.
+++++System.Diagnostics.Process.Start(filePath);
}|code-block|syntax|javascript|499874|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I had the same issue after using the latest library (4.4.0.4099). Here is what I did to solve my problem instead of downgrading. 
<pre><code>// Create The Bitmap Object From EventArgs.
using (Bitmap bitmap = (Bitmap)eventArgs.Frame.Clone())
{
 // Define A File Path.
 string filePath = Path.Combine(Path.GetTempPath(), DateTime.Now.ToString(&quot;ddmmyyyyhhmmssfff&quot;) + &quot;.jpg&quot;);

 // Lock The Bits In Memory.
 BitmapData bitmapData = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, bitmap.PixelFormat);

 // Create OpenCV Image&lt;TColor,TDepth&gt; Object And Add The bitmapData Properties Like So.
 using (Image&lt;Bgr, byte&gt; grayImage = new Image&lt;Bgr, byte&gt;(bitmap.Width, bitmap.Height, bitmapData.Stride, bitmapData.Scan0))
 {
 // Get The Rectangles That Should Be Detected From The Training Data.
 Rectangle[] rectangles = CascadeClassifier.DetectMultiScale(image: grayImage, scaleFactor: 1.2, minNeighbors: 1);

 // Unlock The Bits So We Can Draw To It.
 bitmap.UnlockBits(bitmapData);

 // Loop Each Rectange In The Retanges Collection.
 foreach (Rectangle rectangle in rectangles)
 {
 // Create Graphics Object And Load The Bitmap From The Beginning
 using (Graphics graphics = Graphics.FromImage(bitmap))

 // Create A Pen, Choose Any Colour
 using (Pen pen = new Pen(Brushes.Red))
 {
 // Draw The Rectange Onto The Bitmap.
 graphics.DrawRectangle(pen, rectangle);
 }
 }

 // Create A File Stream And Save The Modified Bitmap
 // We're Using The Above FilePath.
 using (FileStream fs = new FileStream(filePath, FileMode.Create, FileAccess.ReadWrite))
 {
 bitmap.Save(fs, System.Drawing.Imaging.ImageFormat.Jpeg);
 }
 }

 // Open The Saved Image That Should Contain The Drawn Rectangle.
 System.Diagnostics.Process.Start(filePath);
}
</code></pre>

<pre><code> Bitmap bitmap = (Bitmap)eventArgs.Frame.Clone();
 Image&lt;Bgr, byte&gt; grayImage = new Image&lt;Bgr, byte&gt;(bitmap);
 Rectangle[] rectangles = cascadeclassifier.DetectMultiScale(grayImage, 1.2, 1);
 foreach(Rectangle rectangle in rectangles)
 {
 using (Graphics graphics = Graphics.FromImage(bitmap))
 {
 using (Pen pen = new Pen(Color.OrangeRed,1))
 {
 graphics.DrawRectangle(pen, rectangle);
 }
 }
 }
</code></pre>

i have problem at code here:

<code>Image&lt;Bgr, byte&gt; grayImage = new Image&lt;Bgr, byte&gt;(bitmap);</code>

the error is at (bitmap)

the error is :
<code>Error CS1503 Argument 1: cannot convert from 'System.Drawing.Bitmap' to 'byte[*,*,*]'</code>

cannot convert from 'System.Drawing.Bitmap' to 'byte[*,*,*]'

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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Bitmap bitmap = (Bitmap)eventArgs.Frame.Clone(); Image<Bgr, byte> grayImage = new Image<Bgr, byte>(bitmap); Rectangle[] rectangles = cascadeclassifier.DetectMultiScale(grayImage

问无法从“System.Drawing.Bitmap”转换为“字节[ ，，*]”
EN

回答 4

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问无法从“System.Drawing.Bitmap”转换为“字节[ ，，*]”
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