I'm developing a Winform application using c# to have something like photo kiosk that we can see in shopping mall.
I managed to find ways to capture image from webcam and store the captured image using easywebcam component. However, I want to have a photo frame around the webcam streaming video hence when the image is captured, the photo frame is included as well.
I have done research for days but still can't get any idea for this. Can any guru enlighten me for this?
I've used AForge library for working with web cam from C# and I've liked how clean it's API is.
Here the samples how to add timestamp to video, take snapshot, etc:
http://www.aforgenet.com/framework/samples/video.html
If I understand correctly, you need to have original frame when taking snapshot, so you make a copy of it before painting on frame:
Image lastUneditedFrame;
private void VideoSourcePlayer_NewFrame(object sender, ref Bitmap image)
{
if (lastUneditedFrame != null)
{
lastUneditedFrame.Dispose();
}
lastUneditedFrame = image.Clone(new Rectangle(0, 0, image.Width, image.Height), image.PixelFormat);
var graphics = Graphics.FromImage(image);
// do the drawing of photo frame
graphics.Dispose();
}
// on snapshot button click, simply call lastUneditedFrame.Save();
Thanks for your reply, I tested it with the _NewFrame event that you mentioned and add in the overlay method as below:
private void video_NewFrame(object sender, NewFrameEventArgs eventArgs)
{
Bitmap img = (Bitmap)eventArgs.Frame.Clone();
// Perform Overlay here
Graphics camImg = Graphics.FromImage(img);
Bitmap frame = new Bitmap(#"D:\PriusC1.png");
camImg.DrawImage(frame, new Point(100, 100));
camImg.Save();
pictureBox1.Image = img;
}
And it worked like a charm, thank you very much!
Related
I'm working on a graphic application in C# windows form app. I have a form that I can draw on it.
so I created a Graphic object from the form.
void StartPoint()
{
Graphics graphic;
graphic = PaintWindow.CreateGraphics();
}
I want to know how can I export this graphic as a png or jpg file after drawing something.
before this, I searched for this question but I didn't find any useful.
some people resolve this with printing that part of the screen:
graphic.CopyFromScreen(...);
this way is not useful for me because some times I need to transparent my background image.
also, I tried Bitmap way :
private void ExportBTN_Click(object sender, EventArgs e)
{
Bitmap b = new Bitmap(PaintWindow.Width, PaintWindow.Height, graphic);
b.Save(...);
}
but when I save, the image file is completely black.
this is my application:
If you want to draw to an image you want to create your graphics from that image:
using(var myGraphics = Graphics.FromImage(myBitmap))
{
// Do drawing
}
You can then proceed to to use CopyFromScreen and other drawing methods to update the image and then save it.
I am busy with a C# winform software. I use webcam to take a picture which display in a pictureBox.
When I capture the image with the webcam, it captures a zoomed image, and when printing, it is a stretched image. I have tried a variety of SizeMode settings.All give the same result
Because I am not sure where the fault is, I will include as much detail as possible:
Using
using AForge.Video;
using AForge.Video.DirectShow;
Selecting Camera:
webcam = new FilterInfoCollection(FilterCategory.VideoInputDevice);
foreach (FilterInfo VideoCaptureDevice in webcam)
{
cmbVideoList.Items.Add(VideoCaptureDevice.Name);
}
Using camera (btn click):
cam = new VideoCaptureDevice(webcam[cmbVideoList.SelectedIndex].MonikerString);
cam.NewFrame += new NewFrameEventHandler(cam_NewFrame);
cam.Start();
if (cam.IsRunning)
{
btnStart.Hide();
}
btnStop.Show();
}
void cam_NewFrame(object sender, NewFrameEventArgs eventArgs)
{
Bitmap bit = (Bitmap)eventArgs.Frame.Clone();
pboxPhoto.Image = bit;
}
PictureBox size:
Width: 226
Height: 328
Printing code:
PictureBox pict = (PictureBox)pboxPhoto;
pict.SizeMode = PictureBoxSizeMode.Zoom;
e.Graphics.DrawImage(pict.Image, 20, 416, 305, 328);
Here is a sample of the image on software:
enter image description here
Sample of printed image.
enter image description here
The simplest way is to tell the PictureBox to draw itself to a Bitmap.
This can be done with all Controls and the result will include not just the Image and maybe BackgroundImage but also anything drawn in the Paint event as well as any nested Controls.
Here is a simple example:
Size sz = pictureBox1.ClientSize;
using (Bitmap bmp = new Bitmap(sz.Width, sz.Height))
{
pictureBox1.DrawToBitmap(bmp, pictureBox1.ClientRectangle);
// save the image..
bmp.Save(yourfilepath, ImageFormat.Png);
// ..or print it!
}
A few notes:
Due to the using clause the Bitmap get disposed after the last curly, so you would either make use of it inside scope or change to a pattern that disposes of the Bitmap at a later point in time.
The nested Controls will be drawn a reverse order which will cause problem if they are overlapping!
Only nested, not overlayed Controls will be included. Since PictureBox is not a Container (as opposed to e.g. a Panel) it won't do to simply placea, say Label, over it; instead you need to nest it in code, i.e. make the PictureBox its Parent and also set a suitable relative Location..
By default the Bitmap will have the current machine's screen dpi resolution. You cold change it afterwards with bmp.SetResolution()..
I am trying to update the image by drawing circles every time mouse pointer is moved. The pixelBuffer is stored in map object and updated with CircleFilledWithGradientMethod(). I load the pixel buffer in to WriteableBitmap Bitmap and then try to display it by setting image source of an image element in my XAML UI to Bitmap. What happens, is that when I first move my mouse, I see the very first 2 circles drawn but then as I move the mouse, the image does not get updated. Why could that be? Is there a method I should call on Image to force it to redraw? The reason I use stream.WriteAsync two times, when I could have just used it one, is just to show that it is working properly.
private async void TextArea_PointerMoved(object sender, PointerRoutedEventArgs e)
{
Pixel pixel1 = new Pixel(255, 0, 0);
Pixel pixel2 = new Pixel(255, 255, 255);
map.CircleFilledWithGradient((int) pointer.Position.X, (int)pointer.Position.Y, 100, pixel1, pixel2);
using (Stream stream = Bitmap.PixelBuffer.AsStream())
{
stream.WriteAsync(map.pixelData, 0, map.pixelData.Length);
}
map.CircleFilledWithGradient((int)pointer.Position.X+100, (int)pointer.Position.Y, 100, pixel1, pixel2);
using (Stream stream = Bitmap.PixelBuffer.AsStream())
{
stream.WriteAsync(map.pixelData, 0, map.pixelData.Length);
}
this.Image.Source = Bitmap;
}
What I think is happening, is that as soon as I draw the image on the screen, it caches it, and then keeps using the old image. Or is it that the standard Image element does not support redrawing?
Update:
My Bitmap was a private class variable. If I do
WriteableBitmap Bitmap = new WriteableBitmap((int)this.ActualWidth, (int)this.Grid.RowDefinitions[1].ActualHeight);
It all starts to work, but isn't that memory inefficient? Aren't I allocating memory for each new WriteableBitmap each time I move my mouse. And as I have found out, the issue is definitely with with Image component. Why wouldn't it update when I just make changes to it's source, but updates when I change its source to a different object.
`
Is there a method I should call on Image to force it to redraw?
Close. There's a method on WriteableBitmap.
Call WriteableBitmap.Invalidate after you update it to request the refresh.
Assuming the Bitmap was already set as Image.Source, replace the line:
this.Image.Source = Bitmap;
With:
Bitmap.Invalidate();
Why wouldn't it update when I just make changes to its source, but updates when I change its source to a different object.
Setting the Image.Source to the same thing it's already set to is a noop. Most complex Properties ignore "changes" which don't change the existing value. Creating a new WriteableBitmap each time works (very inefficiently) because it's different.
I am working with a fingerprint module and am able to capture and display the output in a picture box (C#). Now picture.Image is null even though picturebox displays an image. So I am trying to save the picturebox image as bmp and then assign that bmp to the same picturebox so that Picturebox.image is not null.
Here is the code :
Bitmap bmp = new Bitmap(picFP.width, picFP.height);
picFP.DrawToBitmap(bmp, picFP.ClientRectangle);
bmp.Save("path", Imageformat.bmp);
picFP.image = bmp;
Here bitmap image saved is blank. What can be the problem?
A PictureBox has three layers it can display and PictureBox.DrawToBitmap will put all three things into the Bitmap:
The BackgroundImage
The Image
Any graphics created in or from the Paint event
If your bitmap comes out black then you have none of the three, or the last you have is all black.
From your description it seems as if you can display the image in the PictureBox.
So I assume that you don't display it in the right way, probably you do it like this:
using (Graphics G = picFP.CreateGraphics())
G.DrawImage(yourCapturedImage, ..)
This will not work as it only creates non-persistent graphics. These go away with e.g. each minimize-restore cycle and are not called from the DrawToBitmap call
If you really want to draw it onto the PB's surface use the Paint event! But the more natural choice would be to set the PB's Image directly:
picFP.Image = yourCapturedImage;
Update 1 As you now reveal that you don't display it yourself but simply give the control handle to the external code objNitgen=picFP.Handle; the same applies: It is that Nitgen draws only onto the surface and the result is non-persistent.
In this case the remedy is either
Taking a screenshot of the result and then work from that. Here is a post that shows you how to capture a control via screenshot..
Or you may want to check if Nitgen will draw into a bitmap directly..
For this you should be to pass it not a handle to the PictureBox but to a Bitmap instead:
private void button_Click(object sender, EventArgs e)
{
Bitmap bmp = new Bitmap(picFP.ClientSize.Width, picFP.ClientSize.Height);
Graphics G = Graphics.FromImage(bmp);
IntPtr dc= G.GetHdc();
objNitgen = dc;
objNitgen.capture();
G.ReleaseHdc(dc);
pictureBox1.Image = bmp; // now display..
bmp.Save(yourfilename); // .. and/or save
}
Update 2
You noted in a comment that doing a manual screenshot also does not capture the image; so it seems the control handle is only used to overlay it with the image much like video overlays do; if this is the case I doubt you can get at the image without using other, more fitting Nitgen SDK methods.
In my C# program I have a Picturebox in which i want to show a stream of video (consecutive frames). I receive raw data, that I then transform into Bitmap or Image. I can show one image at a time without a problem (to reproduce the video stream).
Now my issue is that I want to merge 2 or more bitmaps (like layers) with the same size and alpha values (ARGB) and show it on the picturebox.
I have read lots of websites and posts here on SO, but many use the Graphics class, and I just can't draw it on my application (very likely because i'm new to C#! and already have my program setup, so I didn't want to change the structure).
What i need (to know):
How to overlay two or more Bitmaps with alpha values;
NO pixel manipulation please, can't afford that cost in performance.
Thank you so much in advance!
NOTE: I think this question shouldn't be marked (or closed) as duplicate, because everything i found in SO is done either with pixel manipulation or through the Graphics class. (but I might be wrong!)
EDIT: Possible workaround (NOT the solution to the question)
In
A PictureBox Problem, the 4th answer (from user comecme) tells me to have 2 picturebox, one on top of the other. The only (extra) thing I had to do to make it work with this approach was:
private void Form1_Load(object sender, EventArgs e)
{
pictureBox2.Parent = pictureBox1;
}
Where pictureBox2 will be the one on top.
I won't consider this an answer to this problem, because I consider it a workaround (specially because having more than 10 pictureboxes doesn't seem ideal! lol). That's why I will leave this question opened waiting for a real answer to my question.
EDIT: Resolved! check my answer.
Here is the real answer to my problem.
1) Use a List<Bitmap> to store all the images you want to blend;
2) Create a new Bitmap to hold the final image;
3) Draw each image on top of the final image's graphics using the using statement.
The code:
List<Bitmap> images = new List<Bitmap>();
Bitmap finalImage = new Bitmap(640, 480);
...
//For each layer, I transform the data into a Bitmap (doesn't matter what kind of
//data, in this question) and add it to the images list
for (int i = 0; i < nLayers; ++i)
{
Bitmap bitmap = new Bitmap(layerBitmapData[i]));
images.Add(bitmap);
}
using (Graphics g = Graphics.FromImage(finalImage))
{
//set background color
g.Clear(Color.Black);
//go through each image and draw it on the final image (Notice the offset; since I want to overlay the images i won't have any offset between the images in the finalImage)
int offset = 0;
foreach (Bitmap image in images)
{
g.DrawImage(image, new Rectangle(offset, 0, image.Width, image.Height));
}
}
//Draw the final image in the pictureBox
this.layersBox.Image = finalImage;
//In my case I clear the List because i run this in a cycle and the number of layers is not fixed
images.Clear();
Credits go to Brandon Cannaday in this tech.pro webpage.