How to define picturebox coordinate - c#

I am trying to draw an image on top of another image in a picturebox. They are the same size (125X150). When I paint the second picture at point[0,0] in the picturebox, the two pictures do not line up.Here is my code:
pictureBox1.Image = Image.FromFile("picture\\faces\\face3.png");
Bitmap bmp = new Bitmap(pictureBox1.Image);
Graphics g = Graphics.FromImage(bmp);
g.DrawImage(new Bitmap("picture\\faces\\eyebow1.png"), new Point(0, 0));
g.Dispose();
pictureBox1.Image = bmp;

I figured it out by myself. Although I do not know why:
pictureBox1.Image = Image.FromFile("picture\\faces\\face3.png");
Bitmap bmp = new Bitmap(pictureBox1.Image);
Console.WriteLine(bmp.Width);
Graphics g = Graphics.FromImage(bmp);
pictureBox1.Image = Image.FromFile("picture\\faces\\eyebow1.png");
g.DrawImage(new Bitmap(pictureBox1.Image), new Point(0, 0));
g.Dispose();
pictureBox1.Image = bmp;

Related

Screenshot conversion into grayscale doesn't work. What causes this?

I have a Windows Forms application that takes a screenshot of a specific portion of the screen, then displays it in a picture box (pictureBox1). It works when I don't try to convert it, but I want to convert the image to grayscale or black and white. The problem is when I convert it to grayscale, it still shows the original picture in the picture box.
Here is the code when it works, without the conversion:
private void button1_Click(object sender, EventArgs e)
{
Rectangle rectangle = new Rectangle(660, 200, 600, 100);
pictureBox1.Height = rectangle.Height;
pictureBox1.Width = rectangle.Width;
imageUploader(rectangle);
}
public void imageUploader(Rectangle rectangle)
{
Bitmap bitmap = new Bitmap(rectangle.Width, rectangle.Height, PixelFormat.Format32bppArgb);
Graphics graphics = Graphics.FromImage(bitmap);
graphics.CopyFromScreen(rectangle.Left, rectangle.Top, 0, 0, bitmap.Size, CopyPixelOperation.SourceCopy);
bitmap.Save("proba.jpeg", ImageFormat.Jpeg);
pictureBox1.Image = bitmap;
}
Here is the conversion method, which I tried out:
public void toGrayscale(Bitmap bitmap)
{
Color c;
for (int y = 0; y < bitmap.Height; y++)
{
for (int x = 0; x < bitmap.Width; x++)
{
c = bitmap.GetPixel(x,y);
Color newColor = Color.FromArgb(c.R,0,0);
bitmap.SetPixel(x,y,newColor);
}
}
}
After I used this conversion (see below) the image showed up in the picture box, but it wasn't grayscale.
Here is the modified imageUploader void with the conversion:
public void imageUploader(Rectangle rectangle)
{
Bitmap bitmap = new Bitmap(rectangle.Width, rectangle.Height, PixelFormat.Format32bppArgb);
toGrayscale(bitmap);
Graphics graphics = Graphics.FromImage(bitmap);
graphics.CopyFromScreen(rectangle.Left, rectangle.Top, 0, 0, bitmap.Size, CopyPixelOperation.SourceCopy);
bitmap.Save("proba.jpeg", ImageFormat.Jpeg);
pictureBox1.Image = bitmap;
}
It appears that your issue is here:
public void imageUploader(Rectangle rectangle)
{
Bitmap bitmap = new Bitmap(rectangle.Width, rectangle.Height, PixelFormat.Format32bppArgb);
toGrayscale(bitmap);
Graphics graphics = Graphics.FromImage(bitmap);
graphics.CopyFromScreen(rectangle.Left, rectangle.Top, 0, 0, bitmap.Size, CopyPixelOperation.SourceCopy);
bitmap.Save("proba.jpeg", ImageFormat.Jpeg);
pictureBox1.Image = bitmap;
}
You're converting each pixel of the bitmap to greyscale (oddly it looks like you're only grabbing the red channel) then copying from the screen, which overwrites your conversion. To fix it, all you should need to do is move the toGreyscale after you copy from the screen, like this:
public void imageUploader(Rectangle rectangle)
{
Bitmap bitmap = new Bitmap(rectangle.Width, rectangle.Height, PixelFormat.Format32bppArgb);
Graphics graphics = Graphics.FromImage(bitmap);
graphics.CopyFromScreen(rectangle.Left, rectangle.Top, 0, 0, bitmap.Size, CopyPixelOperation.SourceCopy);
toGrayscale(bitmap); # Moved after the copy from screen
bitmap.Save("proba.jpeg", ImageFormat.Jpeg);
pictureBox1.Image = bitmap;
}
This should fix the issue.
You are converting an empty Bitmap to greyscale, then copying over the (nominally) greyscaled Bitmap with an image from the screen. Here is your code, annotated to describe what it is doing:
// This line creates an empty Bitmap.
Bitmap bitmap = new Bitmap(rectangle.Width, rectangle.Height, PixelFormat.Format32bppArgb);
// This line converts the empty Bitmap to grayscale.
toGrayscale(bitmap);
// This line creates a Graphics drawing surface from your bitmap.
Graphics graphics = Graphics.FromImage(bitmap);
// This line overwrites the image data from your bitmap with an image from the screen.
graphics.CopyFromScreen(rectangle.Left, rectangle.Top, 0, 0, bitmap.Size, CopyPixelOperation.SourceCopy);
You need to find some way to take the data you got from the screen and make it greyscale. You have not done this. You have made a greyscale image, but then you have thrown it away by writing other data on top of it. It happens that that replacement data is not greyscale.

C# - picturebox, graphics.DrawImage and picturebox.Image = null, why?

I'm trying to crop and resize an image in PictureBox1. My code:
//original image for eventually undo
undoImage = pictureBox1.BackgroundImage.Clone() as Image;
Bitmap sourceBitmap = new Bitmap(pictureBox1.BackgroundImage, pictureBox1.Width, pictureBox1.Height);
Graphics g = pictureBox2.CreateGraphics();
g.DrawImage(sourceBitmap, new Rectangle(0, 0, pictureBox2.Width, pictureBox2.Height), rectCropArea, GraphicsUnit.Pixel);
sourceBitmap.Dispose();
And it working properly on two PictureBoxes.
But PictureBox2.Image,PictureBox2.BackgroundImage (and any other including ErrorImage...) = null.
I tried PictureBox.DrawToBitmap, and other, like g.GetHdc() found on google, but unsuccessful.
My question:
How do I properly copy the edited image from PictureBox2 to PictureBox1?
Trivial solution:
undoImage = pictureBox1.BackgroundImage.Clone() as Image;
Bitmap sourceBitmap = new Bitmap(pictureBox1.BackgroundImage, pictureBox1.Width, pictureBox1.Height);
using (Graphics g = Graphics.FromImage(sourceBitmap))
{
g.DrawImage(sourceBitmap, new Rectangle(0, 0, pictureBox2.Width,pictureBox2.Height), rectCropArea, GraphicsUnit.Pixel);
}
pictureBox1.BackgroundImage = sourceBitmap;

C# - Cannot save bitmap to file

recently I started working on my project and unfortunately I have a problem. I want to get sqaures 5x5 from one image, count average color of them and then draw a circle to another Bitmap so I can get a result like this http://imageshack.com/a/img924/9093/ldgQAd.jpg
I have it done, but I can't save to file the Graphics object. I've tried many solutions from Stack, but none of them worked for me.
My code:
//GET IMAGE OBJECT
Image img = Image.FromFile(path);
Image newbmp = new Bitmap(img.Width, img.Height);
Size size = img.Size;
//CREATE NEW BITMAP WITH THIS IMAGE
Bitmap bmp = new Bitmap(img);
//CREATE EMPTY BITMAP TO DRAW ON IT
Graphics g = Graphics.FromImage(newbmp);
//DRAWING...
//SAVING TO FILE
Bitmap save = new Bitmap(size.Width, size.Height, g);
g.Dispose();
save.Save("file.bmp", System.Drawing.Imaging.ImageFormat.Bmp);
The file 'file.bmp' is just a blank image. What am I doing wrong?
First, your Graphics object should be created from the target bitmap.
Bitmap save = new Bitmap(size.Width, size.Height) ;
Graphics g = Graphics.FromImage(save );
Second, flush your graphics before Save()
g.Flush() ;
And last, Dispose() after Save() (or use a using block)
save.Save("file.bmp", System.Drawing.Imaging.ImageFormat.Bmp);
g.Dispose();
It should give you something like this :
Image img = Image.FromFile(path);
Size size = img.Size;
//CREATE EMPTY BITMAP TO DRAW ON IT
using (Bitmap save = new Bitmap(size.Width, size.Height))
{
using (Graphics g = Graphics.FromImage(save))
{
//DRAWING...
//SAVING TO FILE
g.Flush();
save.Save("file.bmp", System.Drawing.Imaging.ImageFormat.Bmp);
}
}

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);

Merging 2 images using C#

I want to merge two pictures in my C# program.
the first one is any picture in grayscale mode, and the second one is like in this picture:
Both of the pictures/images have the same size, and this is my code:
Bitmap first = new Bitmap (picturebox1.image);
Bitmap second = new Bitmap (picturebox2.image);
Bitmap result = new Bitmap (first.width, first.height);
Graphics g = Graphics.FromImage(result);
g.DrawImageUnscaled(first, 0, 0);
g.Flush();
g.DrawImageUnscaled(second, 0, 0);
g.Flush();
picturebox3.image = result;
I can join those picture, but the result has smaller size than the two originals (both pictures have same size). Could anyone give me some suggestions?
Additionally, I want the result picture has condition like this :
if the edge pixel in 2nd picture dropped to the bright side at the 1st one, it will be dark, otherwise when the edge dropped to the dark side, it will be bright (seem glow).
so the text will be semi transparent.
Here's an example of the results I want.
Could anyone give some suggestions please?
It was for joining
Bitmap first = new Bitmap (picturebox1.Image);
Bitmap second = new Bitmap (picturebox2.Image);
Bitmap result = new Bitmap (first.Width+first.Width, first.Height);
Graphics g = Graphics.FromImage(result);
g.DrawImageUnscaled(first, 0, 0);
g.DrawImageUnscaled(second,first.Width, 0);
Try this for merging one on top another . set alpha by yourself ( red: U can use BitMap.MakeTransParent if u not want alpha)
public Bitmap SetImageOpacity(Image image, float opacity)
{
try
{
//create a Bitmap the size of the image provided
Bitmap bmp = new Bitmap(image.Width, image.Height);
//create a graphics object from the image
using (Graphics gfx = Graphics.FromImage(bmp))
{
//create a color matrix object
ColorMatrix matrix = new ColorMatrix();
//set the opacity
matrix.Matrix33 = opacity;
//create image attributes
ImageAttributes attributes = new ImageAttributes();
//set the color(opacity) of the image
attributes.SetColorMatrix(matrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
//now draw the image
gfx.DrawImage(image, new Rectangle(0, 0, bmp.Width, bmp.Height), 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, attributes);
}
return bmp;
}
catch (Exception ex)
{
return null;
}
}
private void button1_Click(object sender, EventArgs e)
{
Bitmap first = new Bitmap(pictureBox1.Image);
Bitmap second = SetImageOpacity(pictureBox2.Image, 0.5f);
//Bitmap result = new Bitmap(first.Width, first.Height);
//fix :
Bitmap result = new Bitmap(Math.Max(first.Width,second.Width), Math.Max(first.Height,second.Height));
Console.WriteLine(first.Width);
Graphics g = Graphics.FromImage(result);
g.DrawImageUnscaled(first, 0, 0);
g.DrawImageUnscaled(second, 0, 0);
pictureBox3.Image = result;
result.Save("result.jpg" );
}
}
}
And Coming For watermark why not you want to use Drawstring with alpha
here is article for all these http://www.codeproject.com/Articles/5034/How-to-implement-Alpha-blending
You need to include the System.Drawing.Imaging namespace to make this code work.
Go through following code:
private void CombineImages(FileInfo[] files)
{
//change the location to store the final image.
string finalImage = #"C:\\MyImages\\FinalImage.jpg";
List imageHeights = new List();
int nIndex = 0;
int width = 0;
foreach (FileInfo file in files)
{
Image img = Image.FromFile(file.FullName);
imageHeights.Add(img.Height);
width += img.Width;
img.Dispose();
}
imageHeights.Sort();
int height = imageHeights[imageHeights.Count - 1];
Bitmap img3 = new Bitmap(width, height);
Graphics g = Graphics.FromImage(img3);
g.Clear(SystemColors.AppWorkspace);
foreach (FileInfo file in files)
{
Image img = Image.FromFile(file.FullName);
if (nIndex == 0)
{
g.DrawImage(img, new Point(0, 0));
nIndex++;
width = img.Width;
}
else
{
g.DrawImage(img, new Point(width, 0));
width += img.Width;
}
img.Dispose();
}
g.Dispose();
img3.Save(finalImage, System.Drawing.Imaging.ImageFormat.Jpeg);
img3.Dispose();
imageLocation.Image = Image.FromFile(finalImage);
}
Follow Link:
http://www.niteshluharuka.com/2012/08/combine-several-images-to-form-a-single-image-using-c/
This codeproject article shows how to watermark an image with text as well as another image.
In summary, what you have to do is draw your watermark image over the image with the desired transparency.

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