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Cyotek ImageBox get zoomed part of image

I am using Cyotek ImageBox to zoom a image, now if I zoom to a part of image and that part is visible in the ImageBox how can I save that part of image which is visible in ImageBox.

The GetSourceImageRegion method allows you to get a RectangleF that describes the part of the image that is visible in the current state of an ImageBox.
The example code below will create a new Bitmap based on the visible part of the image. This example is not zoomed.
Rectangle visibleImageRegion;
Bitmap result;
visibleImageRegion = Rectangle.Round(imageBox.GetSourceImageRegion());
result = new Bitmap(visibleImageRegion.Width, visibleImageRegion.Height);
using (Graphics g = Graphics.FromImage(result))
{
g.DrawImage(imageBox.Image, new Rectangle(Point.Empty, visibleImageRegion.Size), visibleImageRegion, GraphicsUnit.Pixel);
}
This next example does the same as above, but also scales the new image to match the ImageBox
RectangleF visibleImageRegion;
Bitmap result;
double zoomFactor;
int w;
int h;
visibleImageRegion = imageBox.GetSourceImageRegion();
zoomFactor = imageBox.ZoomFactor;
w = Convert.ToInt32(visibleImageRegion.Width * zoomFactor);
h = Convert.ToInt32(visibleImageRegion.Height * zoomFactor);
result = new Bitmap(w, h);
using (Graphics g = Graphics.FromImage(result))
{
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(imageBox.Image, new Rectangle(0, 0, w, h), visibleImageRegion, GraphicsUnit.Pixel);
}
You could hook into the Scroll or Zoomed events of the control to detect when you need to update the image based on user activity.

image getting blurred when enlarging picture box

I am developing an application for image processing. To zoom the image, I enlarge PictureBox. But after enlarging I get below image as result.
But I want result like below image
Here is my Code :
picturebox1.Size = new Size((int)(height * zoomfactor), (int)
(width* zoomfactor));
this.picturebox1.Refresh();

The PictureBox by itself will always create a nice and smooth version.
To create the effect you want you need to draw zoomed versions yourself. In doing this you need to set the
Graphics.InterpolationMode = InterpolationMode.NearestNeighbor;
Then no blurring will happen..
Example:
private void trackBar1_Scroll(object sender, EventArgs e)
{
Bitmap bmp = (Bitmap)pictureBox1.Image;
Size sz = bmp.Size;
Bitmap zoomed = (Bitmap)pictureBox2.Image;
if (zoomed != null) zoomed.Dispose();
float zoom = (float)(trackBar1.Value / 4f + 1);
zoomed = new Bitmap((int)(sz.Width * zoom), (int)(sz.Height * zoom));
using (Graphics g = Graphics.FromImage(zoomed))
{
if (cbx_interpol.Checked) g.InterpolationMode = InterpolationMode.NearestNeighbor;
g.PixelOffsetMode = PixelOffsetMode.Half;
g.DrawImage(bmp, new Rectangle( Point.Empty, zoomed.Size) );
}
pictureBox2.Image = zoomed;
}
Of course you need to avoid setting the PBox to Sizemode Zoom or Stretch!

C#: Image resize and crop at the same time

I'm trying to write a very fast method for creating thumbnails. It will crop and resize an image at the same time. The result image will always be square-like. So having that in mind we can now look at my code :) It is working (as far as I can see):
public static void CreateAndSaveThumbnail(string path, string output, int desiredSize)
{
using (MemoryStream ms = new MemoryStream(File.ReadAllBytes(path)))
using (Bitmap src = new Bitmap(ms))
{
Rectangle crop = src.Width > src.Height ?
new Rectangle((src.Width - src.Height) / 2, 0, src.Height, src.Height) :
new Rectangle(0, 0, src.Width, src.Width);
int size = Math.Min(desiredSize, crop.Width);
using (Bitmap cropped = src.Clone(crop, src.PixelFormat))
using (Bitmap resized = new Bitmap(size, size))
using (Graphics g = Graphics.FromImage(resized))
{
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(cropped, 0, 0, size, size);
resized.Save(output, ImageFormat.Jpeg);
}
}
}
So how the code above works? It crops the middle part for landscape images and top part for portrait images. So this is a standard behavior. Then it resizes the cropped image (it is already a square).
Is this code OK? Could it be faster? How? Any optimizations possible?

Your routine works great but for one slight problem, at least in my desired application. I wanted the routine to crop portrait bitmaps the same as you do for landscape bitmaps; by cropping off half of the excess from the top and half of excess from the bitmap. So I simply duplicated the landscape crop code to the portrait crop code and adjusted as necessary resulting in this:
Rectangle crop = src.Width > src.Height ?
new Rectangle((src.Width - src.Height) / 2, 0, src.Height, src.Height) :
new Rectangle(0, (src.Height - src.Width) / 2, src.Width, src.Width);

How do I resize an image without stretching it?

I am trying to resize an image (bitmap) in C# without stretching the image.
Say the image is 100x100 pixels.
I am looking to make it 100x110 pixels, and leave a white gap at the bottom of the image where it added the extra pixels.
I have done this, but cannot find a way to specify the pixel format. I need it to be 8bppindexed. I've attached an example to show the before and after image.
Here is the code I have so far.
string visit2 = "C:\\users\\moorez\\desktop\\visit2.bmp";
Bitmap orig = new Bitmap(visit2);
int width = orig.Width;
int height = orig.Height;
int newHeight = height + 2;
Bitmap newImage = orig.Clone(new Rectangle(0, 0, width, height), System.Drawing.Imaging.PixelFormat.Format8bppIndexed);
newImage.Save("C:\\users\\moorez\\desktop\\visit3.bmp");
Bitmap test = new Bitmap(width, newHeight);
Graphics g = Graphics.FromImage(test);
g.DrawImage(newImage, new Point(0, 0));
test.Save("C:\\users\\moorez\\desktop\\visit4.bmp");

You can try this
Bitmap bmp = new Bitmap(newImage.Width, newHeight);
Graphics g = Graphics.FromImage(bmp);
g.Clear(Color.White);
g.DrawImageUnscaled(newImage, 0, 0, newImage.Width, newHeight);
bmp.Save(#"C:\\users\\moorez\\desktop\\visit3.bmp", ImageFormat.Jpeg);

Convert Image to Graphic in c#

How to convert Image to Graphic?

You can't convert a Graphics object into an image, as the Graphics object doesn't contain any image data.
The Graphics object is just a tool used to draw on a canvas. That canvas is typically a Bitmap object or the screen.
If the Graphics object is used for drawing on a Bitmap, then you already have the image. If the Graphics object is used for drawing on the screen, you would have to make a screen shot to get an image of the canvas.
If the Graphics object was created from a window control, you could use the control's DrawToBitmap method to render the control on an image instead of on the screen.

You need an Image in order to draw your Graphics on, so you probably already have the image:
Graphics g = Graphics.FromImage(image);

As Darin states, you probably already have the image. If you don't, you can create a new one and draw to that one
Image bmp = new Bitmap(width, height);
using (Graphics g = Graphics.FromImage(bmp)) {
// draw in bmp using g
}
bmp.Save(filename);
Save saves the image to a file on your hard drive.

If you're drawing directly on a Control's graphics, you can create a new Bitmap with the same dimensions as the control and then call Control.DrawToBitmap(). However, the better way to go is usually to start with a Bitmap, draw to its graphics (as suggested by Darin), and then paint the bitmap onto the Control.

The best method to turn graphics into a bitmap is to get rid of the 'using' stuff:
Bitmap b1 = new Bitmap(Screen.PrimaryScreen.Bounds.Width,Screen.PrimaryScreen.Bounds.Height);
Graphics g = Graphics.FromImage(b1);
g.CopyFromScreen(0, 0, Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, new Size(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height));
b1.Save("screen.bmp");
I discovered this while figuring out how to turn graphics into a bitmap, and it works like a charm.
I have some examples on how to use this:
//1. Take a screenshot
Bitmap b1 = new Bitmap(Screen.PrimaryScreen.Bounds.Width,Screen.PrimaryScreen.Bounds.Height);
Graphics g = Graphics.FromImage(b1);
g.CopyFromScreen(0, 0, Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, new Size(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height));
b1.Save("screen.bmp");
//2. Create pixels (stars) at a custom resolution, changing constantly like stars
private void timer1_Tick(object sender, EventArgs e)
{
/*
* Steps to use this code:
* 1. Create new form
* 2. Set form properties to match the settings below:
* AutoSize = true
* AutoSizeMode = GrowAndShrink
* MaximizeBox = false
* MinimizeBox = false
* ShowIcon = false;
*
* 3. Create picture box with these properties:
* Dock = Fill
*
*/
//<Definitions>
Size imageSize = new Size(400, 400);
int minimumStars = 600;
int maximumStars = 800;
//</Definitions>
Random r = new Random();
Bitmap b1 = new Bitmap(imageSize.Width, imageSize.Height);
Graphics g = Graphics.FromImage(b1);
g.Clear(Color.Black);
for (int i = 0; i <r.Next(minimumStars, maximumStars); i++)
{
int x = r.Next(1, imageSize.Width);
int y = r.Next(1, imageSize.Height);
b1.SetPixel(x, y, Color.WhiteSmoke);
}
pictureBox1.Image = b1;
}
With this code, you can use all the commands for the Graphics Class, and copy them to a bitmap, therefore allowing you to save anything designed with the graphics class.
You may use this to your advantage.