Cyotek ImageBox get zoomed part of image - c#

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.

Related

How to zoom in and crop the SVG to specific coordinates in blazor

I am getting the coordinates a1,y1,x2,y2,rotationangle,outputwidth and outputheight from user in my method.
I need to crop the svg using these coordinates but before cropping i need to zoom in the svg on these coordinates and then crop
enter image description here
`double width = xaxis2 - xaxis1; double height = yaxis2 - yaxis1;
Rectangle CropArea = new Rectangle(
Convert.ToInt32(xaxis1),
Convert.ToInt32(yaxis1),
Convert.ToInt32(width),
Convert.ToInt32(height)
);
Bitmap originalImage = new Bitmap(filePath);
using (Bitmap bitMap = new Bitmap(CropArea.Width,
CropArea.Height))
{
using (Graphics g = Graphics.FromImage(bitMap))
{
g.DrawImage(originalImage, new Rectangle(0, 0,
bitMap.Width, bitMap.Height), CropArea, GraphicsUnit.Pixel);
}
}`

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!

Cropping Image(From Screen)

I have read many question about this. But my question is little bit different. What i need to do crop image from screen.
There is my codes
Bitmap photo = new Bitmap(Screen.PrimaryScreen.Bounds.Width,Screen.primaryScreen.Bounds.Height)
Graphics gr = Graphics.FromImage(photo);
gr.CopyFromScreen(0,0,0,0 new size(foto.Width,foto.Height));
picturebox1.Image = photo;
And there my crop codes
Rectangle cropRec = new Rectangle(1,1,1,1);
Bitmap target = new Bitmap(cropRec.Width,cropRec.Height);
using(Graphics g = Graphics.FromImage(target))
{
g.DrawImage(photo,new Rentangle(0,0,target.Width,target.Height),cropRec,GraphicsUnit.Pixel);
}
I want to crop middle part of this photo and compare with itself.
Thanks n advance
To symmetrically crop your image as shown in the following sketch, try creating a Bitmap with margins in the X and Y axis and then cropping the screenshot image by using those margins in CopyFromScreen():
Bitmap printscreen = new Bitmap(Screen.PrimaryScreen.Bounds.Width - 2 * xmargin, Screen.PrimaryScreen.Bounds.Height - 2 * ymargin);
Graphics graphics = Graphics.FromImage(printscreen as Image);
graphics.CopyFromScreen(xmargin, ymargin, 0, 0, printscreen.Size);

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);

c# write text on bitmap

I have following problem. I want to make some graphics in c# windows form.
I want to read bitmap to my program and after it write some text on this bitmap. In the end I want this picture load to pictureBox. And it's my question. How can I do it?
example, how must it work:
Bitmap a = new Bitmap(#"path\picture.bmp");
a.makeTransparent();
// ? a.writeText("some text", positionX, positionY);
pictuteBox1.Image = a;
Is it possible do to?
Bitmap bmp = new Bitmap("filename.bmp");
RectangleF rectf = new RectangleF(70, 90, 90, 50);
Graphics g = Graphics.FromImage(bmp);
g.SmoothingMode = SmoothingMode.AntiAlias;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.DrawString("yourText", new Font("Tahoma",8), Brushes.Black, rectf);
g.Flush();
image.Image=bmp;
Very old question, but just had to build this for an app today and found the settings shown in other answers do not result in a clean image (possibly as new options were added in later .Net versions).
Assuming you want the text in the centre of the bitmap, you can do this:
// Load the original image
Bitmap bmp = new Bitmap("filename.bmp");
// Create a rectangle for the entire bitmap
RectangleF rectf = new RectangleF(0, 0, bmp.Width, bmp.Height);
// Create graphic object that will draw onto the bitmap
Graphics g = Graphics.FromImage(bmp);
// ------------------------------------------
// Ensure the best possible quality rendering
// ------------------------------------------
// The smoothing mode specifies whether lines, curves, and the edges of filled areas use smoothing (also called antialiasing).
// One exception is that path gradient brushes do not obey the smoothing mode.
// Areas filled using a PathGradientBrush are rendered the same way (aliased) regardless of the SmoothingMode property.
g.SmoothingMode = SmoothingMode.AntiAlias;
// The interpolation mode determines how intermediate values between two endpoints are calculated.
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
// Use this property to specify either higher quality, slower rendering, or lower quality, faster rendering of the contents of this Graphics object.
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
// This one is important
g.TextRenderingHint = TextRenderingHint.AntiAliasGridFit;
// Create string formatting options (used for alignment)
StringFormat format = new StringFormat()
{
Alignment = StringAlignment.Center,
LineAlignment = StringAlignment.Center
};
// Draw the text onto the image
g.DrawString("yourText", new Font("Tahoma",8), Brushes.Black, rectf, format);
// Flush all graphics changes to the bitmap
g.Flush();
// Now save or use the bitmap
image.Image = bmp;
References
https://msdn.microsoft.com/en-us/library/system.drawing.graphics.smoothingmode(v=vs.110).aspx
https://msdn.microsoft.com/en-us/library/system.drawing.drawing2d.interpolationmode(v=vs.110).aspx
https://msdn.microsoft.com/en-us/library/system.drawing.graphics.pixeloffsetmode(v=vs.110).aspx
https://msdn.microsoft.com/en-us/library/system.drawing.graphics.textrenderinghint(v=vs.110).aspx
https://msdn.microsoft.com/en-us/library/system.drawing.stringformat(v=vs.110).aspx
https://msdn.microsoft.com/en-us/library/21kdfbzs(v=vs.110).aspx
You need to use the Graphics class in order to write on the bitmap.
Specifically, one of the DrawString methods.
Bitmap a = new Bitmap(#"path\picture.bmp");
using(Graphics g = Graphics.FromImage(a))
{
g.DrawString(....); // requires font, brush etc
}
pictuteBox1.Image = a;
var bmp = new Bitmap(#"path\picture.bmp");
using( Graphics g = Graphics.FromImage( bmp ) )
{
g.DrawString( ... );
}
picturebox1.Image = bmp;
If you want wrap your text, then you should draw your text in a rectangle:
RectangleF rectF1 = new RectangleF(30, 10, 100, 122);
e.Graphics.DrawString(text1, font1, Brushes.Blue, rectF1);
See: https://msdn.microsoft.com/en-us/library/baw6k39s(v=vs.110).aspx

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