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Visual Basic PowerPacks Oval Shape control, displayed as a Circle on the form and I want to increase its size from the center

I have a Visual Basic PowerPacks Oval Shape control, displayed as a Circle on the form and I want to increase its size from the center of the last position, so that I can increase it from all sides i.e. the center, how can I do it, I tried this.
//This code to draw circle on the clicked area.
MouseEventArgs clickArgs = (MouseEventArgs)e; Graphics graphics = this.CreateGraphics();
float circlesize = 100;
int x = Convert.ToInt32(clickArgs.X - circlesize / 2);
int y = Convert.ToInt32(clickArgs.Y - circlesize / 2);
ovalShape1.Location = new Point(x, y);
//To increase its size
ovalShape1.Width = ovalShape1.Width + 10;
ovalShape1.Height = ovalShape1.Height + 10;
The Current code is increasing the size from the last X,Y Position which is not correct. :(

Get coordinates points between x and y

I have a jpeg image in a picturebox, on page load i am drawing the rectangle based on the x(150) and y(440) coordinates. now when i mousemove on the picturebox i need to identify the rectangle by their coordinates and highlight the image. for example see the below image ..
lets take the first rectangle, on mouse move any points inside the rectangle i need to perform some actions.. how to find the coordinates between these x and y for the rectangle?..

A rectangle has 4 Points (edges):
Left
Top
Right
Bottom
If your mouse coordinates (MouseEventArgs properties) are between them, the mouse pointer is in the rectangle.
Are the mouse coordinates greater than right or bottom or lower than left / top, your mouse is outside the rectangle.
Taking #samgak`s Comment:
if(
(point.x >= rectangle.min_x) && (point.x <= rectangle.max_x) &&
(point.y >= rectangle.min_y) && (point.y <= rectangle.max_y)) {
//do something
}
and replacing point with e is exactly what you want.
Maybe the following link will help to understand:
How to check if a point is inside a rectangle

Provided images are the same size and assuming it is stored in variable imageSize (of type System.Drawing.Size) then:
Size imageSize = new Size(...) // define the size here
...
int row = point.y / imageSize.height;
int col = point.x / imageSize.width;
var rect = new Rectangle(col * imageSize.Width, row * imageSize.Height, imageSize.Width, imageSize.Height);
You can then use rect to draw you frame around the image (you may want to inflate the rectangle by a couple of pixels)

Hi Samgak /Clijsters,
I have completed my functionality
// page level declaration
private Rectangle SelectedRect;
public List<Rectangle> listRec = new List<Rectangle>();
// on page load add all the rectangle in the rectanglelist.
private void Highlightimage_Load(object sender, EventArgs e)
{
for (int i = 0; i < table.Rows.Count; i++)
{
int x = Convert.ToInt32(table.Rows[i][0]);
int y = Convert.ToInt32(table.Rows[i][1]);
int width = Convert.ToInt32(table.Rows[i][2]);
int height = Convert.ToInt32(table.Rows[i][3]);
SelectedRect.Size = new Size(width, height);
SelectedRect.X = x;
SelectedRect.Y = y;
listRec.Add(SelectedRect);
}
}
// draw the rectangle
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{ Graphics g = e.Graphics;
foreach (Rectangle rec in listRec)
{
Pen p = new Pen(Color.Red);
g.DrawRectangle(p, rec);
}
}
private Rectangle MakeRectangle(int x0, int y0, int x1, int y1)
{
return new Rectangle(
Math.Min(x0, x1),
Math.Min(y0, y1),
Math.Abs(x0 - x1),
Math.Abs(y0 - y1));
}
//finally on mouse move checking the condition
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
foreach (Rectangle rec in listRec)
{
SelectedRect = MakeRectangle(rec.Left, rec.Top, rec.Right, rec.Bottom);
if (
(e.X >= SelectedRect.Left) && (e.X <= SelectedRect.Right) &&
(e.Y >= SelectedRect.Top) && (e.Y <= SelectedRect.Bottom))
{
MessageBox.Show("test");
}
}
}
Also refered this link
Drawing Multiple Rectangles c#
I thought this will help some one.
Thanks
Dev

How to zoom picturebox along with graphics

I want to zoom picture box along with graphics.
this will Zoom the only image part not the graphics part.
public Image PictureBoxZoom(Image imgP, Size size)
{
Bitmap bm = new Bitmap(imgP, Convert.ToInt32(imgP.Width * size.Width), Convert.ToInt32(imgP.Height * size.Height));
Graphics grap = Graphics.FromImage(bm);
grap.InterpolationMode = InterpolationMode.HighQualityBicubic;
return bm;
}
private void zoomSlider_Scroll(object sender, EventArgs e)
{
if (zoomSlider.Value > 0 && img != null)
{
pictureBox1.SizeMode = PictureBoxSizeMode.CenterImage;
pictureBox1.Image = null;
pictureBox1.Image = PictureBoxZoom(img, new Size(zoomSlider.Value, zoomSlider.Value));
}
}
the source of image is:
img = Image.FromStream(openFileDialog1.OpenFile());
Picture is zooming but when we draw the rectangle outside image then it's not zooming along with image.
See image:

You can do this (rather) easily by scaling the e.Graphics object in the Paint event.. See here for an example!
So to work with you code you probably should add this to the Paint event:
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
g.ScaleTransform(zoom, zoom);
// now do your drawing..
// here just a demo ellipse and a line..
Rectangle rect = panel1.ClientRectangle;
g.DrawEllipse(Pens.Firebrick, rect);
using (Pen pen = new Pen(Color.DarkBlue, 4f)) g.DrawLine(pen, 22, 22, 88, 88);
}
To calculate the zoom factor you need to do a little calculation.
Usually you would not create a zoomed Image but leave that job to the PictureBox with a SizeMode=Zoom.
Then you could write:
float zoom = 1f * pictureBox1.ClientSize.Width / pictureBox1.Image.Width;
To center the image one usually moves the PictureBox inside a Panel. And to allow scrolling one sets the Panel to Autocroll=true;
But since you are creating a zoomed Image you should keep track of the current zoom by some other means.
Note:
But as you use PictureBoxSizeMode.CenterImage maybe your problem is not with the zooming after all?? If your issue really is the placement, not the size of the drawn graphics you need to do a e.Graphics.TranslateTransform to move it to the right spot..

Clear graphics/rectangle without changing colour?

I'm drawing a rectangle onto a Panel object (PanelArea) using the following code:
private void GenerateGraphic()
{
Graphics RandomArea = PanelArea.CreateGraphics();
RandomArea.Clear(Color.Beige);
SolidBrush Brush1 = new SolidBrush(Color.FromArgb(128,220,20,60));
Rectangle rect = new Rectangle();
//Offset is from the top left hand corner.
rect.X = 25;
rect.Y = 25;
rect.Width = 1;
rect.Height = 1;
rect.Inflate(XArea / 2, YArea / 2);
RandomArea.FillRectangle(Brush1, rect);
}
I'm setting the BackgroundImage of the Panel to a snippet of the screen.
I'd like to be able to keep the background image, whilst resetting the rectangle for it to be resized.
I need RandomArea.Clear(Color.Beige) to reset the graphics in order to remove the previous rectangle. The snag is though, is that this places the colour over the background image of the panel.
How can I clear the graphics area/rectangle each time, whilst still being able to view a background image for the Panel?

How can I introduce an overlay on an image

How can I manipulate images to add a semi-transparent 1x1 checked overlay like the second image in C#?

I was able to modify an answer I posted a while ago and create the overlay in code. After the overlay image is created, I use a TextureBrush to fill the area of the original image. The settings in the code below created the following image; you can change the size and colors to suit your needs.
// set the light and dark overlay colors
Color c1 = Color.FromArgb(80, Color.Silver);
Color c2 = Color.FromArgb(80, Color.DarkGray);
// set up the tile size - this will be 8x8 pixels, with each light/dark square being 4x4 pixels
int length = 8;
int halfLength = length / 2;
using (Bitmap overlay = new Bitmap(length, length, PixelFormat.Format32bppArgb))
{
// draw the overlay - this will be a 2 x 2 grid of squares,
// alternating between colors c1 and c2
for (int x = 0; x < length; x++)
{
for (int y = 0; y < length; y++)
{
if ((x < halfLength && y < halfLength) || (x >= halfLength && y >= halfLength))
overlay.SetPixel(x, y, c1);
else
overlay.SetPixel(x, y, c2);
}
}
// open the source image
using (Image image = Image.FromFile(#"C:\Users\Public\Pictures\Sample Pictures\homers_brain.jpg"))
using (Graphics graphics = Graphics.FromImage(image))
{
// create a brush from the overlay image, draw over the source image and save to a new image
using (Brush overlayBrush = new TextureBrush(overlay))
{
graphics.FillRectangle(overlayBrush, new Rectangle(new Point(0, 0), image.Size));
image.Save(#"C:\Users\Public\Pictures\Sample Pictures\homers_brain_overlay.jpg");
}
}
}

Load your original image in to a system.Drawing.Image, then create a graphics object from it. Load your 2nd image of the checker pattern you want to draw, and use the graphics object you created to repeatedly draw the checker image over the original image.
Untested Example
Image Original;
Image Overlay;
Original = new Bitmap(100, 100, System.Drawing.Imaging.PixelFormat.Format32bppArgb); //Load your real image here.
Overlay = new Bitmap(2, 2 ,System.Drawing.Imaging.PixelFormat.Format32bppArgb);//Load your 2x2 (or whatever size you want) overlay image here.
Graphics gr = Graphics.FromImage(Original);
for (int y = 0; y < Original.Height + Overlay.Height; y = y + Overlay.Height)
{
for (int x = 0; x < Original.Width + OverlayWidth; x = x + Overlay.Width)
{
gr.DrawImage(Overlay, x, y);
}
}
gr.Dispose();
After the code executes, Original will now contain the Original image with the overlay applied to it.