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Take a screenshot of part of screen in c# [duplicate]

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C#: how to take a screenshot of a portion of screen
(4 answers)
Closed 1 year ago.
I want to take a screenshot of a specific part of a website using C# or .net Code, I can't create a Windows form application as it must be embedded into something else.
Here is what I got so far:
using System.Drawing.Imaging;
using System.Drawing;
using System;
using System.Windows.Forms;
try
{
//Creating a new Bitmap object
Bitmap captureBitmap = new Bitmap(1024, 768, PixelFormat.Format32bppArgb);
//Bitmap captureBitmap = new Bitmap(int width, int height, PixelFormat);
//Creating a Rectangle object which will
//capture our Current Screen
Rectangle captureRectangle = Screen.AllScreens[0].Bounds;
//Creating a New Graphics Object
Graphics captureGraphics = Graphics.FromImage(captureBitmap);
//Copying Image from The Screen
captureGraphics.CopyFromScreen(captureRectangle.Left,captureRectangle.Top,0,0,captureRectangle.Size);
//Saving the Image File (I am here Saving it in My E drive).
captureBitmap.Save(#"E:\Capture.jpg",ImageFormat.Jpeg);
//Displaying the Successfull Result
MessageBox.Show("Screen Captured");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
This code works fine as long as I am creating a windows form application, but as soon as I change it to console it doesn't work even after adding the "using System.Windows.Forms;" and it produces this error:
//Screen does not exist in the current context
So Is there any solution for this or any other way I could take a screenshot of a specific part of a website Programmatically without connecting to it at all.
Thanks in advance.

I actually found an answer one minute after posting from the suggested links "which btw didn't show in search I did for 2 days for some reason" but anyway
its This question
and its as simple as
Rectangle rect = new Rectangle(0, 0, 100, 100);
Bitmap bmp = new Bitmap(rect.Width, rect.Height, PixelFormat.Format32bppArgb);
Graphics g = Graphics.FromImage(bmp);
g.CopyFromScreen(rect.Left, rect.Top, 0, 0, bmp.Size,
CopyPixelOperation.SourceCopy);
bmp.Save(fileName, ImageFormat.Jpeg);

Screen shoot quality worse than normal

I am trying to capture a part of my screen.
The problem is even if I use png to save the image the quality still worse than if I would just use normal print screen.
Here is the code I use:
//display a save file dialog for the user to set the file name
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Filter = "PNG (*.png)|*.png";
saveFileDialog.FilterIndex = 0;
saveFileDialog.RestoreDirectory = true;
//if the user proceed saving the picture
if (saveFileDialog.ShowDialog() == DialogResult.OK)
{
//simplify code with constant numbers for demo
//get the width of the panel we need the screenshoot off
int x = 10;
//get the height of the panel we need the screenshoot off
int y = 10;
//create the ractangle of the screenshoot panel
Rectangle rect = new Rectangle(x, y, 5, 5);
//create new bitmap
Bitmap bmp = new Bitmap(rect.Width, rect.Height, PixelFormat.Format32bppArgb);
Graphics g = Graphics.FromImage(bmp);
//get the screenshoot of the panel
g.CopyFromScreen(rect.Left, rect.Top, 0, 0, bmp.Size, CopyPixelOperation.SourceCopy);
string fileName = saveFileDialog.FileName;
if (!fileName.Contains(".png"))
fileName += ".png";
bmp.Save(fileName, ImageFormat.Png);
}
EDIT:
Example image form what I take with code:
Normal screenshot:
It does not look so different here, but it is worst.

The top image in your question was rescaled, smaller than the original. This is noticeable in images that contain fine detail, like the ClearType anti-aliasing pixels used to make the text more readable. When they get rescaled, the visual effect is ruined and text looks a lot worse.
It is entirely unclear why the image was rescaled, nothing in your code could cause that. Double-check by using the debugger to inspect the bmp.HorizontalResolution property, it should match the DPI of your video adapter. Simplest explanation that it was done by whatever image viewing program you used, perhaps to make the image fit the window. Try zooming out.

If it's possible to use a external library I suggest you FMUtils.Screenshot. Its available as a NuGet-package.
I just tried it and the quality is like the standard screenshot from windows. Here's a shortexample:
new ComposedScreenshot(new Rectangle(0, 0, 100, 100)).ComposedScreenshotImage.Save(#"PATH_TO_FILE\example-screenshot.png", ImageFormat.Png);
Hope this helps!

The pixel format you use only uses 8 bits each for the different color channels. You could try using PixelFormat64bppARGB to get 16 bits per color.
Resource on the PixelFormat enumeration: http://msdn.microsoft.com/en-us/library/system.drawing.imaging.pixelformat%28v=vs.110%29.aspx

C# drawing on picturebox, not persistent

I have a List<> object, "imagelist", that contains the paths of many images such as .png's. Now, with the following code:
private void paint_picture(PictureBox picture, string pathofpic)
{
Graphics g = picture.CreateGraphics();
Bitmap drawnpic = null;
if (imagelist.ContainsKey(picture.Name))
{
drawnpic = new Bitmap(pathofpic);
g.DrawImage(drawnpic, 0, 0, picture.Size.Width, picture.Size.Height);
imagelist[picture.Name] = pathofpic;
}
drawnpic.Dispose();
g.Dispose();
}
I call this every time the card's image is changed, but I can't seem to make the image persist on the picturebox, when I drag the picturebox across the form (for example, over other pictureboxes). The click and drag code is just moving the picturebox with the mouse, not really relevant.
I've tried invalidating the form when I de-select the image, but it doesn't do anything.
Is there something I'm missing? Screenshot below, I dragged one image around the form and it overwrote the other images it moved across:

That’s how painting works – you have to handle its Paint event and keep painting the same thing each time it needs repainting.
What you can do is draw on top of your original image:
Bitmap b = new Bitmap(picture.Image);
using (Graphics g = Graphics.FromImage(b)) {
using (Bitmap drawnpic = new Bitmap(pathofpic)) {
g.DrawImage(drawnpic, 0, 0, b.Width, b.Height);
}
}
picture.Image = b;
Then you’d save the original image somewhere and probably use it instead of picture.Image in the new Bitmap line.
And PascalCase for method names, please. ;)

Transparency and GIF in .NET -- Inconsistent behavior

I am trying to edit and save an image using the .net Bitmap class. Some of the pixels are transparent, and they get converted to black under certain circumstances. If I save the same image like this:
image.Save("copy1.png", System.Drawing.Imaging.ImageFormat.Png);
image.Save("copy2.gif", System.Drawing.Imaging.ImageFormat.Gif);
image.Save("copy3.gif");
(Image being originally a gif) the first and third are correct retaining the transparency, but the middle one sets all the transparent pixels to black. I'm not sure what I am doing wrong, AFAIK the last two lines should be equivalent.
Here is a sample program of what I am talking about:
using System.Drawing;
using System.Net;
namespace TestGif
{
class Program
{
static void Main(string[] args)
{
Bitmap bitmap = new Bitmap(WebRequest.Create(
"http://rlis.com/images/column/ie_icon.gif")
.GetResponse()
.GetResponseStream());
int width = bitmap.Width;
int height = bitmap.Height;
Bitmap copy = new Bitmap(width, height);
var graphics = Graphics.FromImage(copy);
graphics.DrawImage(bitmap, new Point(0, 0));
copy.Save("copy1.png", System.Drawing.Imaging.ImageFormat.Png);
copy.Save("copy2.gif", System.Drawing.Imaging.ImageFormat.Gif);
copy.Save("copy3.gif");
}
}
}

Your last line
copy.Save("copy3.gif");
does not save as gif file, but as png, since the extension is not sufficient to specify the saving format.
To make a transparent gif, use something like
Color c = copy.GetPixel(0, 0);
copy.MakeTransparent(c);
Your code is creating a new bitmap, possibly losing the original gif informations.

List view control displaying distorted images

I have a problem with the ListView control in a windows forms application.
Even if I create a thumbnail image or resize the real one I get distorted images in the list view.
The image looks like when you zoom in an image very much.
I first thought that the GetThumbnailImage is couseing this but I used a resize code I found here and I have the same result.
I also did not found any bug related to list view control so I gues I'm doing something wrong but I just can't figure out what.
Here is the code I use:
lsvPictures.LargeImageList = m_imagesList;
lsvPictures.LargeImageList.ImageSize = new Size(100, 100);
lsvPictures.View = View.LargeIcon;
lsvPictures.CheckBoxes = true;
for (int i = 0; i < ofd.FileNames.Length; i++)
{
filename = ofd.FileNames[i].ToString();
ListViewItem lvi = new ListViewItem(filename);
m_imagesList.Images.Add(ResizeImage(Image.FromFile(filename), 100, 100));
lvi.ImageIndex = i;
lsvPictures.Items.Add(lvi);
}
And this is the function that resizes images:
public static System.Drawing.Bitmap ResizeImage(System.Drawing.Image image,
int width, int height)
{
//a holder for the result
Bitmap result = new Bitmap(width, height);
//use a graphics object to draw the resized image into the bitmap
using (Graphics graphics = Graphics.FromImage(result))
{
//set the resize quality modes to high quality
graphics.CompositingQuality =
System.Drawing.Drawing2D.CompositingQuality.HighQuality;
graphics.InterpolationMode =
System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
graphics.SmoothingMode =
System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//draw the image into the target bitmap
graphics.DrawImage(image, 0, 0, result.Width, result.Height);
}
//return the resulting bitmap
return result;
}
Thank you!
Mosu'
I just found the source of the problems:
m_imagesList.ColorDepth = ColorDepth.Depth16Bit;
It seams that, as default, the ColorDepth of the ImageList is 8 bit (or 4 bit, but my guess is 8). If I change this to at least 16 bit everything looks very nice.
To those with similar problems: I changed my Thumbnail method a lot before I realised that the ListView control is not using the color depth the images were having. I put the result of my method on a PictureBox control and saw that the function was working corectly. Atfer this I googled a lot ... and found that silly ColorDepth property.

How did you set the resolution for your image. Also, did what did you set the PixelFormat value to when you created the bitmap? I have a list of images loading into my list view that I am resizing similar to how you are and it is working fine without any distortion in the resulting thumbnail images that are created.
Here is a snippet from my resize method.
Bitmap bitmap = new Bitmap(width, height, PixelFormat.Format24bppRgb);
bitmap.SetResolution(image.HorizontalResolution, image.VerticalResolution);
using (Graphics graphics = Graphics.FromImage(bitmap))
{
graphics.Clear(Color.Red);
graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphics.DrawImage(image,
new Rectangle(destinationX, destinationY, destinationWidth, destinationHeight),
new Rectangle(sourceX, sourceY, originalWidth, originalHeight),
GraphicsUnit.Pixel);
}
return bitmap;

I was also using a ListView in WinForms to display directories, and had the same problem. I suggest that you check the image file type: icon files (.ico) tend to end up distorted, so try to use an image file with the .png extension. This works for me:
ListView listView = new ListView();
ImageList imageList = new ImageList();
// add image to list:
imageList.Images.Add("image_key", image_path);
// give the listview the imagelist:
listView.SmallImageList = imageList;
// add item to listview:
listView.Items.Add("item_text", "image_key");