I'm trying to draw text on a bitmap which is then shown in a picture box. Code is the following:
private void button2_Click(object sender, EventArgs e)
{
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("myText", new Font("Tahoma", 8), Brushes.Black, rectf);
g.Flush();
pictureBox1.Image = bmp;
}
When I run the program and press the button2 I get an error.
It says:
An unhandled exception of type 'System.ArgumentException' occurred in System.Drawing.dll
Additional information: Incorrect parameter.
I can't find any mistake there. What could be wrong?
You need to specify an existing file name. The more flexible solution is to just specify dimensions of your bitmap. For example, next code creates a text in a bitmap
Bitmap bmp = new Bitmap(200, 200);
//your code
bmp.Save(#"D:\filename.bmp");
g.Flush();
creates next image at D:\filename.bmp
If you want to alter existing bitmap by adding new text, use Image.FromFile method, like:
Bitmap bmp = (Bitmap)Image.FromFile(#"D:\filename.bmp");
Related
I am currently writing a .NET Core App to run cross-platform. Part of this is App is Drawing a Text and overlay onto a Bitmap.
So I added System.Drawing.Common and finally ended up with a working Code(On Windows) like this:
public static Bitmap WriteText(Bitmap bmp, string txt)
{
RectangleF rectf = new RectangleF(0, 0, bmp.Width, bmp.Height);
// Create graphic object that will draw onto the bitmap
using (Graphics g = Graphics.FromImage(bmp))
{
g.SmoothingMode = SmoothingMode.AntiAlias;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.TextRenderingHint = TextRenderingHint.AntiAliasGridFit;
StringFormat format = new StringFormat()
{
Alignment = StringAlignment.Center,
LineAlignment = StringAlignment.Center
};
// dampening
using (Brush brush = new SolidBrush(Color.FromArgb(69, Color.Black)))
g.FillRectangle(brush, rectf);
var fSize = 26;
var fFam = Fonts.GetDefaultFontName();
// Draw the path
GraphicsPath p = new GraphicsPath();
p.AddString(txt, fFam, (int)FontStyle.Regular, g.DpiX * fSize / 72.2f, rectf, format);
g.DrawPath(new Pen(Color.FromArgb(180, Color.Black), 8), p);
// Draw the text
g.DrawString(txt, new Font(fFam, fSize), Brushes.White, rectf, format);
// Flush all graphics changes to the bitmap
g.Flush();
}
// Now save or use the bitmap
return bmp;
}
On Windows Outputs are generated correctly or as expected like this for Example:
But when run on my Ubuntu/linux server, the GraphicsPath/Shadow would generate like this:
My first thought was an Error in the DPI-calculation since my Server doesn't have an X-Server installed but apparently the GraphicsPath is drawn correct; just the position is wrong?
*Editnote: Also the "Formatting" apparently works on the usual DrawString... so thats extra weird
Maybe I've missed something but this looks like a platform-specific bug to me?
I'd appreciate any help & opinions at this point... Thanks
I am trying to print 40x40mm labels from a programmatically created image.
The label must have text on it, and a logo. Since the label is fairly small I am finding myself fiddling with how to do proper smooting, antialias and such.
I have tried multipl settings but I am not sure it's even the right way to go about it.
First I draw the container Bitmap:
private Bitmap DrawLabelCircle()
{
var labelImage = new Bitmap(152, 152);
using (Graphics gfx = Graphics.FromImage(labelImage))
{
var pen = new Pen(Color.Black, 1);
gfx.SmoothingMode = SmoothingMode.AntiAlias;
gfx.DrawEllipse(pen, 1, 1, 150, 150);
}
return labelImage;
}
Then I overlay different text snippets on that container Bitmap
private Bitmap DrawDistributorTextRectangle(string text)
{
var bitmap = new Bitmap(113, 113);
var rectangle = new Rectangle(0, 0, 110, 110);
using (Graphics gfx = Graphics.FromImage(bitmap))
{
gfx.SmoothingMode = SmoothingMode.AntiAlias;
gfx.InterpolationMode = InterpolationMode.HighQualityBicubic;
gfx.PixelOffsetMode = PixelOffsetMode.HighQuality;
var font = new Font(FontFamily.GenericSansSerif, 5, FontStyle.Regular, GraphicsUnit.Point);
var brush = new SolidBrush(Color.Black);
gfx.TextRenderingHint = TextRenderingHint.AntiAlias;
gfx.DrawString(text, font, brush, rectangle);
}
bitmap.RotateFlip(RotateFlipType.Rotate270FlipNone);
return bitmap;
}
Overlay that text on the previous created Bitmap.
private Bitmap DistributorTextOverlay(Bitmap source, Bitmap overlay)
{
var result = new Bitmap(source.Width, source.Height);
var graphics = Graphics.FromImage(result);
graphics.CompositingMode = CompositingMode.SourceOver;
graphics.SmoothingMode = SmoothingMode.HighQuality;
graphics.DrawImage(source, 0, 0);
graphics.DrawImage(overlay, 120, 0);
return result;
}
And the I save it.
var imageCodecInfo = ImageCodecInfo.GetImageEncoders().First(encoder => encoder.MimeType == "image/png");
var encoderInfo = new EncoderParameters() { Param = { [0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L) } };
image.SetResolution(203, 203);
image.Save("img.png", imageCodecInfo, encoderInfo);
The big challenge here is that the image I get is actually looking alright, all things considered.
But when I print it, it looks terrible pixelated.
I would really like to give some pointers for what settings I should apply to all these bitmaps before saving the final result, and what settings should apply for the final image I save.
I am by no means a .NET graphics expert so all help is much appreciated.
40mm is 1.5748 inches. So if you plan to print it at 300 dpi resolution, your bitmap should be 1.5748*300 = 472 pixels instead of 152.
In c# and Visual Studio Windows forms I have loaded an image into a picture box (pictureBox2) and then cropped it and show in another picture box (pictureBox3).
Now I want to save what is inside pictureBox3 as an image file.
How can I do this?
private void crop_bttn_Click(object sender, EventArgs e)
{
Image crop = GetCopyImage("grayScale.jpg");
pictureBox2.Image = crop;
Bitmap sourceBitmap = new Bitmap(pictureBox2.Image,
pictureBox2.Width, pictureBox2.Height);
Graphics g = pictureBox3.CreateGraphics();
g.DrawImage(sourceBitmap, new Rectangle(0, 0,
pictureBox3.Width, pictureBox3.Height), rectCropArea, GraphicsUnit.Pixel);
sourceBitmap.Dispose();
}
Never use control.CreateGraphics! Either draw into a Bitmap bmp using a Graphics g = Graphics.FromImage(bmp) or in the Paint event of a control, using the e.Graphics parameter..
Here is a cropping code that draws into a new Bitmap and that makes use of your controls etc but changes a few things:
It uses a Graphics object that is created from a new Bitmap
It make use of using clauses to make sure it won't leak
It takes the size of the pictureBox3.ClientSize so it won't include any borders..
private void crop_bttn_Click(object sender, EventArgs e)
{
Image crop = GetCopyImage("grayScale.jpg");
pictureBox2.Image = crop;
Bitmap targetBitmap = new Bitmap(pictureBox3.ClientSize.Width,
pictureBox3.ClientSize.Height);
using (Bitmap sourceBitmap = new Bitmap(pictureBox2.Image,
pictureBox2.ClientSize.Width, pictureBox2.ClientSize.Height))
{
using (Graphics g = Graphics.FromImage(targetBitmap))
{
g.DrawImage(sourceBitmap, new Rectangle(0, 0,
pictureBox3.ClientSize.Width, pictureBox3.ClientSize.Height),
rectCropArea, GraphicsUnit.Pixel);
}
}
if (pictureBox3.Image != null) pictureBox3.Image.Dispose();
pictureBox3.Image = targetBitmap;
targetBitmap.Save(somename, someFormat);
}
The alternative would be to..:
move all your code to the Paint event
replace the Graphics g = pictureBox3.CreateGraphics(); be Graphics g = e.Graphics;
insert these two lines to the click event:
Bitmap targetBitmap = new Bitmap(pictureBox3.ClientSize.Width,
pictureBox3.ClientSize.Height);
pictureBox3.DrawToBitmap(targetBitmap, pictureBox3.ClientRectangle);
The method PictureBox.CreateGraphics() should not be used unless you know what you are doing because it can cause some not-so-obvious problems. For example, in you scenario, the image in pictureBox3 will disappear when you minimize or resize the window.
A better way is to draw to a bitmap, which you also can save:
var croppedImage = new Bitmap(pictureBox3.Width, pictureBox3.Height);
var g = Graphics.FromImage(croppedImage);
g.DrawImage(crop, new Point(0, 0), rectCropArea, GraphicsUnit.Pixel);
g.Dispose();
//Now you can save the bitmap
croppedImage.Save(...);
pictureBox3.Image = croppedImage;
Btw, please use more reasonable variable names, especially for pictureBox1..3.
When I run the code below to take screenshot, I get an error like A generic error occurred in GDI+. How can I resolve this issue or any other way to take screenshot of current window?
protected void Page_Load(object sender, EventArgs e) {
Bitmap bitmap = new Bitmap(100, 200);
Graphics graphics = Graphics.FromImage(bitmap as System.Drawing.Image);
graphics.CopyFromScreen(0, 0, 0, 0, bitmap.Size);
bitmap.Save("c:\\screenshot.jpeg", ImageFormat.Jpeg);
}
You should use
bitmap.Save(#"c:\\screenshot.jpeg", ImageFormat.Jpeg);
Also why you define bitmap again, it's not needed:
Graphics graphics = Graphics.FromImage(bitmap);
i am planing to display my generated bitmap in gtk image.
but it only support Pixbuf.
how to convert Bitmap in to Pixbuf.
can i use TypeConverter to do this?
Done it different way.
other than convert i have reloaded the image.
protected void OnBtnGenClicked (object sender, EventArgs e)
{
Bitmap bmp = new Bitmap(300, 300);
using (Graphics g = Graphics.FromImage(bmp))
{
Font font = new Font("Arial", 20, FontStyle.Bold, GraphicsUnit.Point);
g.Clear(Color.White);
g.DrawString(txtMessage.Text, font, Brushes.Black, 0, 0);
}
bmp.Save("d:/image.png", ImageFormat.Png);
var buffer = System.IO.File.ReadAllBytes ("d:/image.png");
var pixbuf = new Gdk.Pixbuf (buffer);
image1.Pixbuf = pixbuf;
}