拍照并直接使用EDSDK 2.8将图像保存到PC
题
我是EDSDK 2.8的新手
目前,我的程序可以拍照。但是,当拍摄照片时,该图片暂时存储在佳能相机中的缓冲区中。我想知道如何将其保存到PC?
有人有任何想法吗?还是c#或vb.net中的示例代码?
解决方案
这是我所做的:
首先,您必须在创建对象时注册回调事件(即,图片)。我以我创建的RegisterEvents方法做到了这一点:
// Register OBJECT events
edsObjectEventHandler = new EDSDK.EdsObjectEventHandler(objectEventHandler);
error = EDSDK.EdsSetObjectEventHandler(this.CameraDevice,
EDSDK.ObjectEvent_All, edsObjectEventHandler, IntPtr.Zero);
if (EDSDK.EDS_ERR_OK != error)
{
throw new CameraEventRegistrationException("Unable to
register object events with the camera!", error);
}
这 objectEventHandler
是创建图片时将调用的方法。
该方法需要符合由API决定的接口。这是该方法的实现示例:
/// <summary>
/// Registered callback function for recieving object events
/// </summary>
/// <param name="inEvent">Indicate the event type supplemented.</param>
/// <param name="inRef">Returns a reference to objects created by the event.</param>
/// <param name="inContext">Passes inContext without modification</param>
/// <returns>Status 0 (OK)</returns>
private uint objectEventHandler(uint inEvent, IntPtr inRef, IntPtr inContext)
{
switch (inEvent)
{
case EDSDK.ObjectEvent_DirItemCreated:
this.invokeNewItemCreatedEvent(new NewItemCreatedEventArgs(getCapturedItem(inRef)));
Console.WriteLine("Directory Item Created");
break;
case EDSDK.ObjectEvent_DirItemRequestTransfer:
Console.WriteLine("Directory Item Requested Transfer");
break;
default:
Console.WriteLine(String.Format("ObjectEventHandler: event {0}, ref {1}", inEvent.ToString("X"), inRef.ToString()));
break;
}
return 0x0;
}
在此示例中,我转过身来产生自己的事件,该事件具有对流对象的引用。这是由以下代码处理的:
/// <summary>
/// Gets a photo or video clip from the camera
/// </summary>
/// <param name="directoryItem">Reference to the item that the camera captured.</param>
/// <returns></returns>
private CapturedItem getCapturedItem(IntPtr directoryItem)
{
uint err = EDSDK.EDS_ERR_OK;
IntPtr stream = IntPtr.Zero;
EDSDK.EdsDirectoryItemInfo dirItemInfo;
err = EDSDK.EdsGetDirectoryItemInfo(directoryItem, out dirItemInfo);
if (err != EDSDK.EDS_ERR_OK)
{
throw new CameraException("Unable to get captured item info!", err);
}
// Fill the stream with the resulting image
if (err == EDSDK.EDS_ERR_OK)
{
err = EDSDK.EdsCreateMemoryStream((uint)dirItemInfo.Size, out stream);
}
// Copy the stream to a byte[] and
if (err == EDSDK.EDS_ERR_OK)
{
err = EDSDK.EdsDownload(directoryItem, (uint)dirItemInfo.Size, stream);
}
// Create the returned item
CapturedItem item = new CapturedItem();
if (err == EDSDK.EDS_ERR_OK)
{
IntPtr imageRef = IntPtr.Zero;
err = EDSDK.EdsCreateImageRef(stream, out imageRef);
if (err == EDSDK.EDS_ERR_OK)
{
EDSDK.EdsImageInfo info;
err = EDSDK.EdsGetImageInfo(imageRef, EDSDK.EdsImageSource.FullView, out info);
if (err == EDSDK.EDS_ERR_OK)
{
item.Dimensions = new com.waynehartman.util.graphics.Dimension((int)info.Width, (int)info.Height);
EDSDK.EdsRelease(imageRef);
}
}
}
if (err == EDSDK.EDS_ERR_OK)
{
byte[] buffer = new byte[(int)dirItemInfo.Size];
GCHandle gcHandle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
IntPtr address = gcHandle.AddrOfPinnedObject();
IntPtr streamPtr = IntPtr.Zero;
err = EDSDK.EdsGetPointer(stream, out streamPtr);
if (err != EDSDK.EDS_ERR_OK)
{
throw new CameraDownloadException("Unable to get resultant image.", err);
}
try
{
Marshal.Copy(streamPtr, buffer, 0, (int)dirItemInfo.Size);
item.Image = buffer;
item.Name = dirItemInfo.szFileName;
item.Size = (long)dirItemInfo.Size;
item.IsFolder = Convert.ToBoolean(dirItemInfo.isFolder);
return item;
}
catch (AccessViolationException ave)
{
throw new CameraDownloadException("Error copying unmanaged stream to managed byte[].", ave);
}
finally
{
gcHandle.Free();
EDSDK.EdsRelease(stream);
EDSDK.EdsRelease(streamPtr);
}
}
else
{
throw new CameraDownloadException("Unable to get resultant image.", err);
}
}
其他提示
我也这样做是因为我在摄像机中没有存储卡,并且希望在发送拍照命令后将图像传输到主机计算机。这是对我有用的 ObjectEventHandler
当佳能EOS50D中未安装存储卡时,请调用回调。
EdsUInt32 setsaveto = kEdsSaveTo_Both;
err = EdsSetPropertyData(camera, kEdsPropID_SaveTo, 0, sizeof(setsaveto), &setsaveto);
瞧,回调被打来电话,然后我可以继续做 getCapturedItem()
作为韦恩(Wayne)在较早文章中发布的功能。
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