I cannot seem to programmatically create a colored bitmap to display in a PictureBox. The bitmap saves normally as a file, but is faded at the edges when displayed in a PictureBox. Here is simplified code used to create and display the Bitmap (in actual code, the bitmap generation is completely separate from the form, so forcing the bitmap size to match the picturebox size isn't possible):
Bitmap Bmp = new Bitmap(4, 4, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
using (Graphics gfx = Graphics.FromImage(Bmp))
using (SolidBrush brush = new SolidBrush(Color.BlueViolet))
{
gfx.FillRectangle(brush, 0, 0, 4, 4);
}
Then set the Image value on a PictureBox to the generated Bitmap:
pictureBox1.Image = Bmp;
Here is the resulting bitmap displayed in a 300x300 picturebox:
How do I set the Image on the PictureBox so that it displays the colored bitmap properly (full solid)?
EDIT: I am restricted to generating smaller source bitmaps, so upscaling into a PictureBox is unavoidable. The problem appears when the generated source bitmap is 4px or 100px square, so I believe these are relevant cases.
EDIT: The PictureBox scaling should be set to stretch or zoom for the issue to manifest. In this example case the 4x4 source bitmap is stretched to 300x300.
EDIT: The basic problem is PictureBox's inability to upscale small bitmaps into large controls. This is confusing because the Bitmap upscales nicely into a PictureBox.Background image. Unless you have a magic bullet that will fix the image upscaling problem, I think it might be best to go for clear and simple workarounds in your answer.
You are generating a 4x4 bitmap and it's being stretched. Specify the size to match the picture box instead:
int width = pictureBox1.Width;
int height = pictureBox1.Height;
var Bmp = new Bitmap(width, height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
using (Graphics gfx = Graphics.FromImage(Bmp))
using (var brush = new SolidBrush(Color.BlueViolet))
{
gfx.FillRectangle(brush, 0, 0, width, height);
}
pictureBox1.Image = Bmp;
You will need to turn anti-aliasing off. Also, since you are using one color for the whole picturebox, why not make the bitmap 1x1? If you need it 4x4, change the int the top of the example from 1 to 4.
int hw = 1;
Bitmap Bmp = new Bitmap(hw, hw,
System.Drawing.Imaging.PixelFormat.Format24bppRgb);
using (Graphics gfx = Graphics.FromImage(Bmp))
{
// Turn off anti-aliasing and draw an exact copy
gfx.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.None;
gfx.CompositingMode = System.Drawing.Drawing2D.CompositingMode.SourceCopy;
using (SolidBrush brush = new SolidBrush(Color.BlueViolet))
{
gfx.FillRectangle(brush, 0, 0, hw, hw);
}
}
pictureBox1.Image = Bmp;
UPDATE
Since you are still having the same issue by setting the picturebox to the image, you will have to get the graphics object from the picturebox and draw directly on it.
The code is very similar.
using (Graphics gfx = Graphics.FromImage(pictureBox1.Image))
{
// Turn off anti-aliasing and draw an exact copy
gfx.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.None;
gfx.CompositingMode = System.Drawing.Drawing2D.CompositingMode.SourceCopy;
using (SolidBrush brush = new SolidBrush(Color.BlueViolet))
{
gfx.FillRectangle(brush, 0, 0,
pictureBox11.Width - 1,
pictureBox11.Height - 1);
}
}
// Force the picturebox to redraw with the new image.
// You could also use pictureBox11.Refresh() to do the redraw.
pictureBox11.Invalidate();
I tried to test your code and the image were properly displayed.
But when i used this code:
Rectangle srcRect = New Rectangle(0, 0, Bmp.Width, Bmp.Height);
Rectangle dstRect = New Rectangle(0, 0, PictureBox1.Width, PictureBox1.Height);
g = PictureBox1.CreateGraphics;
g.DrawImage(Bmp, dstRect, srcRect, GraphicsUnit.Pixel);
g.Dispose();
I did get exactly your result. In order to fix it:
Rectangle srcRect = New Rectangle(0, 0, Bmp.Width - 1, Bmp.Height - 1);
Rectangle dstRect = New Rectangle(0, 0, PictureBox1.Width, PictureBox1.Height);
g = PictureBox1.CreateGraphics;
g.DrawImage(Bmp, dstRect, srcRect, GraphicsUnit.Pixel);
g.Dispose();
Edit:
So you have the bitmap and you want to stretch it. And the bitmap has ane solid color. Do this insted:
Color pixelColor = Bmp.GetPixel(0, 0);
PictureBox1.BackColor = pixelColor;
valter
Related
Bitmap tmp = new Bitmap(1000, 1000);
Graphics g = Graphics.FromImage(tmp);
Image img = Bitmap.FromFile(LoadPath);
Image img2 = Bitmap.FromFile(TempPath);
g.DrawImage(img, 0, 0);
g.DrawImage(img2, 250, 250);
'img' and 'img2' are an image with transparent parts.
When I run the code, transparent parts appear in black.
Why is that?
Have a look here
private void MakeTransparent_Example1(PaintEventArgs e)
{
// Create a Bitmap object from an image file.
Bitmap myBitmap = new Bitmap("Grapes.gif");
// Draw myBitmap to the screen.
e.Graphics.DrawImage(myBitmap, 0, 0, myBitmap.Width,
myBitmap.Height);
// Make the default transparent color transparent for myBitmap.
myBitmap.MakeTransparent();
// Draw the transparent bitmap to the screen.
e.Graphics.DrawImage(myBitmap, myBitmap.Width, 0,
myBitmap.Width, myBitmap.Height);
}
I need to fill an rectangle on bottom of my image, but not over the image, so it should be a kind of append a rectangle to bottom of image.
What I have for now:
private void DrawRectangle()
{
string imageFilePath = #"c:\Test.jpg";
Bitmap bitmap = (Bitmap)Image.FromFile(imageFilePath);
using (Graphics graphics = Graphics.FromImage(bitmap))
{
using (Image img = Image.FromFile(imageFilePath))
{
SolidBrush brush = new SolidBrush(Color.Black);
int width = img.Width;
int height = img.Height - 350;
graphics.FillRectangle(brush, 0, height, width, 350);
}
}
bitmap.Save(#"c:\Test1.jpg");
}
But this is over the image.
Any idea's?
Thank you.
You need to know the dimensions of your original image in order to set the size of the new bitmap, which must be larger to accommodate the rectangle.
private void DrawRectangle()
{
string imageFilePath = #"c:\Test.jpg";
int rectHeight = 100;
using (Image img = Image.FromFile(imageFilePath)) // load original image
using (Bitmap bitmap = new Bitmap(img.Width, img.Height + rectHeight)) // create blank bitmap of desired size
using (Graphics graphics = Graphics.FromImage(bitmap))
{
// draw existing image onto new blank bitmap
graphics.DrawImage(img, 0, 0, img.Width, img.Height);
SolidBrush brush = new SolidBrush(Color.Black);
// draw your rectangle below the original image
graphics.FillRectangle(brush, 0, img.Height, img.Width, rectHeight);
bitmap.Save(#"c:\Test1.bmp");
}
}
take a look at the FillRectangle() method overloads.. it has one with the following definition: FillRectangle(Brush brush, int PositionX, int PositionY, int Width, int Height)
your problem most likely stems on using an improper overload for what you're doing.
I have a PictureBox with lots of transparent png's drawn into...
Now I'd like to save the content of this PictureBox to a file, but without the transparency.
How can I do this?
I have already tried to remove transparency from the Image like this, but it didn't work, I still got a transparent image after the save.
...
removeTransparency(pictureBox.Image).Save(saveFileDialog.FileName);
private Bitmap removeTransparency(Image transparentImage)
{
Bitmap src = new Bitmap(transparentImage);
Bitmap newImage = new Bitmap(src.Size.Width, src.Size.Height);
Graphics g = Graphics.FromImage(newImage);
g.DrawRectangle(new Pen(new SolidBrush(Color.White)), 0, 0, newImage.Width, newImage.Height);
g.DrawImage(src, 0, 0);
return newImage;
}
You may cycle through all pixel (please not using GetPixel/SetPixel) to change the color or you may create another bitmap with the same size, create a graphics context from the image, clear the image with your favorite background color and then draw your image on it (so transparent pixels simply will be replaced by the background color).
Example
Did you do something like this?
public static Bitmap Repaint(Bitmap source, Color backgroundColor)
{
Bitmap result = new Bitmap(source.Width, source.Height, PixelFormat.Format32bppArgb);
using (Graphics g = Graphics.FromImage(result))
{
g.Clear(backgroundColor);
g.DrawImage(source, new Rectangle(0, 0, source.Width, source.Height));
}
return result;
}
I'm trying to resize my image after copying it from the screen, and can't figure out how to do it. The tutorials I've been reading recommend using Graphics.DrawImage to resize the image, but when I run this code, it doesn't resize.
Bitmap b = new Bitmap(control.Width, control.Height);
Graphics g = Graphics.FromImage(b);
g.CopyFromScreen(control.Parent.RectangleToScreen(control.Bounds).X, control.Parent.RectangleToScreen(control.Bounds).Y, 0, 0, new Size(control.Bounds.Width, control.Bounds.Height), CopyPixelOperation.SourceCopy);
g.DrawImage(b, 0,0,newWidth, newHeight);
Any help would be appreciated, thanks!
Try this. Graphics won't "replace" the image when you use DrawImage - it draws the input image on its source, which is the same as the the image you're trying to draw to it.
Probably a more concise way to do this but.....
Bitmap b = new Bitmap(control.Width, control.Height);
using (Graphics g = Graphics.FromImage(b)) {
g.CopyFromScreen(control.Parent.RectangleToScreen(control.Bounds).X,
control.Parent.RectangleToScreen(control.Bounds).Y, 0, 0,
new Size(control.Bounds.Width, control.Bounds.Height),
CopyPixelOperation.SourceCopy);
}
Bitmap output = new Bitmap(newWidth, newHeight);
using (Graphics g = Graphics.FromImage(output)) {
g.DrawImage(b, 0,0,newWidth, newHeight);
}
Is there any reason why you can't just use a PictureBox control? That control takes care of stretching for you.
I have a c#-class that looks roughly like this:
class ImageContainer
{
Image image;
internal ImageContainer getResized(int width, int height)
{
Bitmap bmp = new Bitmap(width, height);
//Create a System.Drawing.Graphics object from the Bitmap which we will use to draw the high quality scaled image
System.Drawing.Graphics gr = System.Drawing.Graphics.FromImage(bmp);
//Set the System.Drawing.Graphics object property SmoothingMode to HighQuality
gr.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//Set the System.Drawing.Graphics object property CompositingQuality to HighQuality
gr.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
//Set the System.Drawing.Graphics object property InterpolationMode to High
gr.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
//Draw the original image into the target Graphics object scaling to the desired width and height
System.Drawing.Rectangle rectDestination = new System.Drawing.Rectangle(0, 0, width, height);
gr.DrawImage(image, rectDestination, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel);
//dispose / release resources
ImageContainer ic = new ImageContainer();
ic.image = bmp;
return ic;
}
}
The resizing works fine, but DrawImage doesn't draw the most right an lower pixel-fragments when scaling down an image.
the problem is solved by
gr.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
:)