Getting a particular Portion of Image (Picture) - c#

I want to cut the the specific portion of the the picture and use it to compare the cropped image with another stored in the HDD. The problem is that I don't know how to get a specific section of the source image. I know the location (X,Y) of the image to be cropped.

This will load the original and create a cropped version starting at (0,0) and with dimensions of 64x64.
Bitmap original = new Bitmap( #"C:\SomePath" );
Rectangle srcRect = new Rectangle( 0, 0, 64, 64 );
Bitmap cropped = (Bitmap)original.Clone( srcRect, original.PixelFormat );
BTW, you don't specify if this is WinForms or WPF, so going with WinForms as I don't really know WPF image manipulation functions.

For those who need to use the cropped image for their website within img-tag , you need some more code (just advicing, because i needed it myself)
Take the code above plus this:
byte[] imgbytes;
using (MemoryStream stream = new MemoryStream())
{
cropped.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
imgbytes = stream.ToArray();
}
<img src="#String.Format("data:image/png;base64,{0}", Convert.ToBase64String(imgbytes))" />

Related

image overlay picture from Camer_net library showing a lot of pink color

I am making an windows form application in which i am overlaying an image during a webcam stream from the laptop.
the overlayed image is showing absurd colours. it is showing alot of pink colour. is there anything i can do to make the overlayed image look properly.
i am using the camera_Net Library to connect to the webcam
suggestions for overlaying an image during during a webcam video shall also be appreciated.
here is my code to draw the image
string filepath = #"E:\office\lux desktop app\Camera_Net-master\Camera_Net-master\Samples\CameraControlTool\water_PNG3290.png";
Bitmap bitmap1 = new Bitmap(filepath);
g.DrawImage(bitmap1, new Rectangle(400 , 0, 250, 600));
here is the look of the image during webcam stream
and here is the orignal image being overlayed
I think the problem is the image itself. It's an .png image, so I it has the possibility of an alpha-value. The white in the back is cropped out but in between the water, the light blue values are pink.
I would first try to use an easier image. Something like this. I think this will work just fine. Then search for some more complex images and try to find the weak-spot and find some alternative options to bring the image in to the cam.
As #Roman R pointed out that g point correctly to an incorrect background,
the problem was indeed with color format, so the solution is to use the correct image pixelformat based on your image.
here is the complete code
Bitmap bmp = new Bitmap(w, h, PixelFormat.Format32bppRgb);
Graphics g = Graphics.FromImage(bmp);
Image newImage;
newImage = Properties.Resources.red_frame_03;
using (Bitmap oldBmp = new Bitmap(newImage))
using (Bitmap newBmp = new Bitmap(oldBmp))
using (Bitmap targetBmp = newBmp.Clone(new Rectangle(0, 0, newBmp.Width, newBmp.Height), PixelFormat.Format16bppArgb1555))
{
g.DrawImage(targetBmp, new Rectangle(100, 0, 350, 350));
}

C# Zoomed image in Picturebox gets cropped in top left

I want to make very simplistic paint/image editor. Mainly, for pixel editing, but that doesn't seem relevant.
To ease up my effort, I decided to keep the image size at 16x16.
I populate the form, add a PixelBox and slap a default image on it.
Of course, I need to make the pixels visible, set the interpolation to NearestNeighbor.
Then, I stretch the pixelbox to 320x320. And there the situation arises.
The image is displayed as thus:
Cropped image
Could someone shed some light on this? This is just a 16x16 image with a checkerboard pattern that I made, but I can't figure out why it is displayed with that offset at the top left.
Also, no code as been yet added. I assume this is default behavior?
If you look at the examples on the page that exact same error happens, so it must be a bug on the PixelBox.
Instead of using a custom control for this type of operation just use the standard PictureBox and scale the image by yourself:
public Bitmap ScaleBitmap(Bitmap src, Size NewSize)
{
Bitmap bmp = new Bitmap(NewSize.Width, NewSize.Height, src.PixelFormat);
Graphics g = Graphics.FromImage(src);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor;
g.DrawImage(src, new Rectangle(Point.Empty, NewSize), new Rectangle(0, 0, src.Width, src.Height), GraphicsUnit.Pixel);
g.Dispose();
return bmp;
}

Draw the change portion of image on another image

suppose i have two images img1.jpg and img2.jpg. using some routine i could extract the difference between two images. now difference is saved in another bitmap variable called diff
here is code
Bitmap diff = new Bitmap(bounds.Width, bounds.Height);
Graphics g = Graphics.FromImage(diff);
g.DrawImage(secondImg, 0, 0, bounds, GraphicsUnit.Pixel);
g.Dispose();
i know the difference in terms of rectangle and also save the difference in diff variable. now i want to merge or draw this difference on my first image. i tried with code like
Graphics g1 = Graphics.FromImage(firstImg);
g1.DrawImage(secondImg, 0, 0, bounds, GraphicsUnit.Pixel);
g1.Dispose();
but it is not working because when i open my first image img1.jpg then i am seeing any changes in that image. i want to draw the changes on my first image img1.jpg. what is wrong in my code which is not being able to dump or draw the changes on first image.
basically i have to reconstruct img1, if i have img2 and difference between img2 and img1.
please guide me. thanks

How to search for an image on screen in C#?

I want to search for an image on screen using C# or other .NET languages(like powershell). Something like i give an image location in the file system and the code consider the whole screen as an image and search the image in the file system in the big image(the screen) then returns the image position on screen. I can't find this kind of things in the .net classes.
Thanks.
This is a pretty specific problem, which is why you won't find it in the .NET Framework. You should break down your problem in smaller pieces:
Load image from file on disk
Use System.Drawing.Image.FromFile().
Acquire an image of the screen, i.e. a screen shot
Use System.Drawing.Graphics.CopyFromScreen():
Bitmap CaptureScreen()
{
var image = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format32bppArgb);
var gfx = Graphics.FromImage(image);
gfx.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy);
return image;
}
Find image inside image
See answer to this question.
i have made a program which used a lib i coded in c# which will return the value of x and y of a small image inside a bigger image (screenshot) you can see all the details here https://www.nulled.io/topic/22223-an-advanced-image-search-library-saeedsearchdll/

How to render images in real-time

I am looking for a solution\software that I can use in order to render buttons in real time.
That is, I have an image and text, and I want them to be an image altogether in realtime.
Thank you
You can dynamically create an image based on text using the System.Drawing namespace.
private Bitmap CreateBitmapImage(string imageText, string imageUrl)
{
Bitmap myBitmap = new Bitmap(imageUrl);
Graphics g = Graphics.FromImage(myBitmap);
g.DrawString(imageText, new Font("Tahoma", 40), Brushes.White, new PointF(0, 0));
return (objBmpImage);
}
Once you have the Bitmap object in memory you can save it to the disk and call it's location from the web.
Bitmap bmp = CreateBitmapImage("my picture", #"C:\myBasePic.bmp");
bmp.Save(#"C:\bla.png", System.Drawing.Imaging.ImageFormat.png);
It would be good if you can specify why such requirement is there. One of such scenario that I had encountered was need of image buttons with different text (round corners with shaded background) - this can easily be achieved using CSS. If you really want to combine an image and text together then you can do that at server side (using say System.Drawing types) and serve the combined image over a handler/web-service.

Categories