We Keep Coding

Distorted label text when resizing

I have a dynamic window with labels on it. The window is a HUD and changes size depending on its parent window. However, one of the labels becomes distorted when resized.
The font of the labels are resized according to the screen size like so:
float fontSize = this.Width / 128 /getScalingFactor();
and the scaling factor is calculated as follows:
//Gets the scaling factor of the current dpi settings
protected float getScalingFactor()
{
Graphics g = Graphics.FromHwnd(IntPtr.Zero);
IntPtr desktop = g.GetHdc();
int LogicalScreenHeight = GetDeviceCaps(desktop, (int)DeviceCap.VERTRES);
int PhysicalScreenHeight = GetDeviceCaps(desktop, (int)DeviceCap.DESKTOPVERTRES);
int logpixelsy = GetDeviceCaps(desktop, (int)DeviceCap.LOGPIXELSY);
float screenScalingFactor = (float)PhysicalScreenHeight / (float)LogicalScreenHeight;
float dpiScalingFactor = (float)logpixelsy / (float)96;
return dpiScalingFactor; // 1.25 = 125%
//return screenScalingFactor;
}
And the designer code for the labels. There are labels that holds numbers as well and they are using identical settings. However, they don't get distorted but the username label does.
this.labelUsername.AutoSize = true;
this.tableLayoutPanel1.SetColumnSpan(this.labelUsername, 2);
this.labelUsername.Font = new System.Drawing.Font("Arial", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
this.labelUsername.ForeColor = System.Drawing.Color.White;
this.labelUsername.Location = new System.Drawing.Point(3, 0);
this.labelUsername.Name = "labelUsername";
this.labelUsername.Size = new System.Drawing.Size(56, 14);
this.labelUsername.TabIndex = 3;
this.labelUsername.Text = "Username";
this.labelUsername.TextAlign = System.Drawing.ContentAlignment.MiddleLeft;
I've tried changing some numbers of the font size and scaling factor. I've tried changing some of the settings in the designer code as well. Unfortunately no success so far.
Maybe someone recognize the issue and can point me to what causes this. I'm assuming there is some mis-match with the label and window DPI perhaps. But that doesn't explain why the numbers doesn't get the same problem.

First a clarification. I'm building on a open source project which I'm not 100% familiar with.
So after poking around some more I realized that there is another function which also controls the HUD colors. Unless I added a forecolor to my label there as well, I got that distorted looking text.
I'm assuming that this method is called everytime the window is resizing and when my label wasn't updated with a color there, it got a transparent color. However, because the forecolor had been set at startup it showed as a border around the transparent text because it wasn't resized.

Graphis.DrawString always uses the default font

I have a project in which I create an image with rotated text around an invisible circle.
The drawing in itself is working just fine. However, it seems that no matter the font I use, I always get the same result, which is I assume some low quality default font.
Here is the code :
Bitmap objBmpImage = new Bitmap(1000, 1000);
System.Drawing.Text.InstalledFontCollection installedFontCollection = new System.Drawing.Text.InstalledFontCollection();
FontFamily[] fontFamilies = installedFontCollection.Families;
System.Drawing.Font objFont = new System.Drawing.Font(fontFamilies.Where(x => x.Name == "Arial").FirstOrDefault(),10);
Graphics objGraphics = Graphics.FromImage(objBmpImage);
objGraphics.Clear(Color.Transparent);
float angle = (float)360.0 / (float)competences.Count();
objGraphics.TranslateTransform(500, 450);
objGraphics.RotateTransform(-90 - (angle / 3));
int nbComptetence = competences.Count();
int indexCompetence = 0;
foreach (T_Ref_Competence competence in competences)
{
byte r, g, b;
HexToInt(competence.T_Ref_CompetenceNiveau2.T_Ref_CompetenceNiveau1.Couleur, out r, out g, out b);
Brush brush = new System.Drawing.SolidBrush(Color.FromArgb(255,r,g,b));
if (indexCompetence * 2 < nbComptetence)
{
objGraphics.DrawString(competence.Nom, objFont, brush, 255, 0);
objGraphics.RotateTransform(angle);
}
else
{
objGraphics.RotateTransform(180);
objGraphics.RotateTransform(angle/2);
float textSize = objGraphics.MeasureString(competence.Nom, objFont).Width;
objGraphics.DrawString(competence.Nom, objFont, brush, -253 - textSize, 0);
objGraphics.RotateTransform(angle);
objGraphics.RotateTransform(-180);
objGraphics.RotateTransform(-angle / 2);
}
indexCompetence++;
}
I get the font using the installed families like this
System.Drawing.Text.InstalledFontCollection installedFontCollection = new System.Drawing.Text.InstalledFontCollection();
FontFamily[] fontFamilies = installedFontCollection.Families;
System.Drawing.Font objFont = new System.Drawing.Font(fontFamilies.Where(x => x.Name == "Arial").FirstOrDefault(),10);
I tried using other font but the result is always the same. Is there anything I am missing ? If not, what could be the reason ?
Thanks,
EDIT : To answer the question, what is it that I want exactly, consider this :
This image is a screenshot of a web site I am making. The chart in the middle was generated using charts.js, but its limitation force me to draw the text as a background image. It actually takes most of my screen so it can't really get much bigger than this. As you can see, the text font is pretty blurry and I would simply want it to be easier to read. I though the font was the problem, but I don't really know.
I am not really familiar with the whole image drawing part of C#, so if there are is better way to draw my text (which can change depending of many variables), I will gladly try other things.

Option 1: change text rendering
objGraphics.TextRenderingHint = TextRenderingHint.SingleBitPerPixel
Option 2: change the mode of anti aliasing
objGraphics.InterpolationMode=InterpolationMode.NearestNeighbor;
Option 3: change the DPI of the image
You'll get the best result if you scale the input image and then draw the text in higher DPI.
The default DPI for a Bitmap are 96. Probably the JS library exported with that setting.
If you want a smoother rendering of the font, you need to increase the DPI, e.g.
objBmpImage.SetResolution(1200,1200);
If you do so, you probably need to increase the number of pixels your Bitmap has.
If the "ugly" text just fitted the 1000x1000 picture, you now need 1000*1200/96=12500 pixels.
Before the change (using Arial 10 pt):
After the change (still using Arial 10 pt):
Note that the size in centimeters doesn't change. So it will still print well.

Image is not drawn at the correct spot

Bitmap image = ReadBitmap("image.png");
Bitmap imageCopy = new Bitmap(image);
Bitmap canvas = new Bitmap(imageCopy.Width+100, imageCopy.Height);
// From this bitmap, the graphics can be obtained, because it has the right PixelFormat
using(Graphics g = Graphics.FromImage(canvas))
{
// Draw the original bitmap onto the graphics of the new bitmap
g.DrawImage(image, 0, 0);
}
// Use tempBitmap as you would have used originalBmp
InputPictureBox.Image = image;
OutputPictureBox.Image = canvas;
I haven't understood the output of this c# code.
The original image is not placed at the correct position. It should have been at (0, 0).
Also, I need a black background.
So, what is going on and how to correct this?

You are loading an Image, then a copy of this source is created using:
Bitmap bitmap = new Bitmap();
When you create a copy of an Image this way, you sacrifice/alter some details:
Dpi Resolution: if not otherwise specified, the resolution is set to the UI resolution. 96 Dpi, as a standard; it might be different with different screen resolutions and scaling. The System in use also affects this value (Windows 7 and Windows 10 will probably/possibly provide different values)
PixelFormat: If not directly copied from the Image source or explicitly specified, the PixelFormat is set to PixelFormat.Format32bppArgb.
From what you were saying, you probably wanted something like this:
var imageSource = Image.FromStream(new MemoryStream(File.ReadAllBytes(#"[SomeImageOfLena]"))), true, false)
var imageCopy = new Bitmap(imageSource.Width + 100, imageSource.Height, imageSource.PixelFormat))
imageCopy.SetResolution(imageSource.HorizontalResolution, imageSource.VerticalResolution);
using (var g = Graphics.FromImage(imageCopy)) {
g.Clear(Color.Black);
g.CompositingMode = CompositingMode.SourceCopy;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(imageSource, (imageCopy.Width - imageSource.Width) / 2, 0);
pictureBox1.Image?.Dispose();
pictureBox2.Image?.Dispose();
pictureBox1.Image = imageSource;
pictureBox2.Image = imageCopy;
}
This is the result:
(The upper/lower frame black color is actually the Picturebox background color)
When the original Image Dpi Resolution is different from the base Dpi Resolution used when creating an Image copy with new Bitmap(), your results may be different from what is expected.
This is what happens with a source Image of 150, 96 and 72 Dpi in the same scenario:
Another important detail is the IDisposable nature of the Image object.
When you create one, you have to Dispose() of it; explicitly, calling the Dispose method, or implicitly, enclosing the Image contructor in a Using statement.
Also, possibly, don't assign an Image object directly loaded from a FileStream.
GDI+ will lock the file, and you will not be able to copy, move or delete it.
With the file, all resources tied to the Images will also be locked.
Make a copy with new Bitmap() (if you don't care of the above mentioned details), or with Image.Clone(), which will preserve the Image Dpi Resolution and PixelFormat.

I am not completely clear on what you are actually needing to do. But anyway, here is a WPF-friendly example of how to draw an image at a specific position inside another image.
Note if all you want to do is display the image in different size and/or put a black border around it, there are much simpler ways to do simply that, without having to create a second image, such as just laying out the image inside a panel that already has the border style you want.
Notice that I am using classes from the System.Windows.Media namespace because that is what WPF uses. These don't mix easily with the older classes from System.Drawing namespace (some of the class names conflict, and Microsoft's .Net framework lacks built-in methods for converting objects between those types), so normally one needs to simply decide whether to use one or the other sets of drawing tools. I assume you have been trying to use System.Drawing. Each has its own pros and cons that would take too long to explain here.
// using System.Windows.Media;
// using System.Windows.Media.Imaging;
private void DrawTwoImages()
{
// For InputPictureBox
var file = new Uri("C:\\image.png");
var inputImage = new BitmapImage(file);
// If your image is stored in a Resource Dictionary, instead use:
// var inputImage = (BitmapImage) Resources["image.png"];
InputPicture.Source = inputImage;
// imageCopy isn't actually needed for this example.
// But since you had it in yours, here is how it's done, anyway.
var imageCopy = inputImage.Clone();
// Parameters for setting up our output picture
int leftMargin = 50;
int topMargin = 5;
int rightMargin = 50;
int bottomMargin = 5;
int width = inputImage.PixelWidth + leftMargin + rightMargin;
int height = inputImage.PixelHeight + topMargin + bottomMargin;
var backgroundColor = Brushes.Black;
var borderColor = (Pen) null;
// Use a DrawingVisual and DrawingContext for drawing
DrawingVisual dv = new DrawingVisual();
using (DrawingContext dc = dv.RenderOpen())
{
// Draw the black background
dc.DrawRectangle(backgroundColor, borderColor, new Rect(0, 0, width, height));
// Copy input image onto output image at desired position
dc.DrawImage(inputImage, new Rect(leftMargin, topMargin,
inputImage.PixelWidth, inputImage.PixelHeight));
}
// For displaying output image
var rtb = new RenderTargetBitmap( width, height, 96, 96, PixelFormats.Pbgra32 );
rtb.Render(dv);
OutputPicture.Source = rtb;
}

How to implement pan/zoom on gigapixel bitmaps?

In my project, I'm using (uncompressed 16-bit grayscale) gigapixel images which come from a high resolution scanner for measurement purposes. Since these bitmaps can not be loaded in memory (mainly due to memory fragmentation) I'm using tiles (and tiled TIFF on disc). (see StackOverflow topic on this)
I need to implement panning/zooming in a way like Google Maps or DeepZoom. I have to apply image processing on the fly before presenting it on screen, so I can not use a precooked library which directly accesses an image file. For zooming I intend to keep a multi-resolution image in my file (pyramid storage). The most useful steps seem to be +200%, 50% and show all.
My code base is currently C# and .NET 3.5. Currently I assume Forms type, unless WPF gives me great advantage in this area. I have got a method which can return any (processed) part of the underlying image.
Specific issues:
hints or references on how to implement this pan/zoom with on-demand generation of image parts
any code which could be used as a basis (preferably commercial or LGPL/BSD like licenses)
can DeepZoom be used for this (i.e. is there a way that I can provide a function to provide a tile at the right resulution for the current zoom level?) ( I need to have pixel accurate addressing still)

This CodeProject article: Generate...DeepZoom Image Collection might be a useful read since it talks about generating a DeepZoom image source.
This MSDN article has a section Dynamic Deep Zoom: Supplying Image Pixels at Run Time and links to this Mandelbrot Explorer which 'kinda' sounds similar to what you're trying to do (ie. he is generating specific parts of the mandelbrot set on-demand; you want to retrieve specific parts of your gigapixel image on-demand).
I think the answer to "can DeepZoom be used for this?" is probably "Yes", however as it is only available in Silverlight you will have to do some tricks with an embedded web browser control if you need a WinForms/WPF client app.
Sorry I can't provide more specific answers - hope those links help.
p.s. I'm not sure if Silverlight supports TIFF images - that might be an issue unless you convert to another format.

I decided to try something myself. I came up with a straightforward GDI+ code, which uses the tiles I've already got. I just filter out the parts which are relevant for current clipping region. It works like magic! Please find my code below.
(Form settings double buffering for the best results)
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
Graphics dc = e.Graphics;
dc.ScaleTransform(1.0F, 1.0F);
Size scrollOffset = new Size(AutoScrollPosition);
int start_x = Math.Min(matrix_x_size,
(e.ClipRectangle.Left - scrollOffset.Width) / 256);
int start_y = Math.Min(matrix_y_size,
(e.ClipRectangle.Top - scrollOffset.Height) / 256);
int end_x = Math.Min(matrix_x_size,
(e.ClipRectangle.Right - scrollOffset.Width + 255) / 256);
int end_y = Math.Min(matrix_y_size,
(e.ClipRectangle.Bottom - scrollOffset.Height + 255) / 256);
// start * contain the first and last tile x/y which are on screen
// and which need to be redrawn.
// now iterate trough all tiles which need an update
for (int y = start_y; y < end_y; y++)
for (int x = start_x; x < end_x; x++)
{ // draw bitmap with gdi+ at calculated position.
dc.DrawImage(BmpMatrix[y, x],
new Point(x * 256 + scrollOffset.Width,
y * 256 + scrollOffset.Height));
}
}
To test it, I've created a matrix of 80x80 of 256 tiles (420 MPixel). Of course I'll have to add some deferred loading in real life. I can leave tiles out (empty) if they are not yet loaded. In fact, I've asked my client to stick 8 GByte in his machine so I don't have to bother about performance too much. Once loaded tiles can stay in memory.
public partial class Form1 : Form
{
bool dragging = false;
float Zoom = 1.0F;
Point lastMouse;
PointF viewPortCenter;
private readonly Brush solidYellowBrush = new SolidBrush(Color.Yellow);
private readonly Brush solidBlueBrush = new SolidBrush(Color.LightBlue);
const int matrix_x_size = 80;
const int matrix_y_size = 80;
private Bitmap[,] BmpMatrix = new Bitmap[matrix_x_size, matrix_y_size];
public Form1()
{
InitializeComponent();
Font font = new Font("Times New Roman", 10, FontStyle.Regular);
StringFormat strFormat = new StringFormat();
strFormat.Alignment = StringAlignment.Center;
strFormat.LineAlignment = StringAlignment.Center;
for (int y = 0; y < matrix_y_size; y++)
for (int x = 0; x < matrix_x_size; x++)
{
BmpMatrix[y, x] = new Bitmap(256, 256, PixelFormat.Format24bppRgb);
// BmpMatrix[y, x].Palette.Entries[0] = (x+y)%1==0?Color.Blue:Color.White;
using (Graphics g = Graphics.FromImage(BmpMatrix[y, x]))
{
g.FillRectangle(((x + y) % 2 == 0) ? solidBlueBrush : solidYellowBrush, new Rectangle(new Point(0, 0), new Size(256, 256)));
g.DrawString("hello world\n[" + x.ToString() + "," + y.ToString() + "]", new Font("Tahoma", 8), Brushes.Black,
new RectangleF(0, 0, 256, 256), strFormat);
g.DrawImage(BmpMatrix[y, x], Point.Empty);
}
}
BackColor = Color.White;
Size = new Size(300, 300);
Text = "Scroll Shapes Correct";
AutoScrollMinSize = new Size(256 * matrix_x_size, 256 * matrix_y_size);
}
Turned out this was the easy part. Getting async multithreaded i/o done in the background was a lot harder to acchieve. Still, I've got it working in the way described here. The issues to resolve were more .NET/Form multithreading related than to this topic.
In pseudo code it works like this:
after onPaint (and on Tick)
check if tiles on display need to be retrieved from disc
if so: post them to an async io queue
if not: check if tiles close to display area are already loaded
if not: post them to an async io/queue
check if bitmaps have arrived from io thread
if so: updat them on screen, and force repaint if visible
Result: I now have my own Custom control which uses roughly 50 MByte for very fast access to arbitrary size (tiled) TIFF files.

I guess you can address this issue following the steps below:
Image generation:
segment your image in multiple subimages (tiles) of a small resolution, for instace, 500x500. These images are depth 0
combine a series of tiles with depth 0 (4x4 or 6x6), resize the combination generating a new tile with 500x500 pixels in depth 1.
continue with this approach until get the entire image using only a few tiles.
Image visualization
Start from the highest depth
When user drags the image, load the tiles dynamically
When the user zoom a region of the image, decrease the depth, loading the tiles for that region in a higher resolution.
The final result is similar to Google Maps.

How do I resize a System.Windows.Forms.ToolBar?

I've not bothered with panels, docking, or anchors. I've simply thrown together a ToolBar control (not ToolStrip) and seem unable to size it.
System.Windows.Forms.ToolBar tb = new System.Windows.Forms.ToolBar();
// Reports 292x28 (approx) if I check width and height
// Basically the width of the form and I assume a default height
tb.Size = new System.Drawing.Size(195, 48);
// Reports 48x48, but does not actually create buttons of that size
// (It reports 48x48 because I'm retrieving 48x48 icons from a ResourceManager (resx))
tb.ButtonSize = new System.Drawing.Size(48, 48); //
The closest thing I found to making my ToolBar taller was:
http://bytes.com/topic/c-sharp/answers/241614-changing-height-toolbar-button
Although it's rather dated. And I didn't understand it. ToolBarButtons don't have Height, Width, or Size properties.
I'm using SharpDevelop, coding completely by hand on Vista, with all the .NET frameworks.
EDIT:
Here is the EXACT code that I am currently using.
#region ImageList/Toolbar
ImageList toolbarImages = new ImageList();
Image wizardToolbarImage = (Bitmap) rm.GetObject("wizard");
Image optionsToolbarImage = (Bitmap) rm.GetObject("configure");
toolbarImages.Images.Add(wizardToolbarImage);
toolbarImages.Images.Add(optionsToolbarImage);
ToolBar toolbarMain = new ToolBar();
toolbarMain.Size = new Size(195, 25); // no effect
ToolBarButton wizardToolbarButton = new ToolBarButton();
ToolBarButton optionsToolbarButton = new ToolBarButton();
wizardToolbarButton.ImageIndex = 0;
wizardToolbarButton.ToolTipText = "Wizard!";
optionsToolbarButton.ImageIndex = 1;
optionsToolbarButton.ToolTipText = "Options!";
toolbarMain.Buttons.Add(wizardToolbarButton);
toolbarMain.Buttons.Add(optionsToolbarButton);
toolbarMain.Appearance = ToolBarAppearance.Normal;
toolbarMain.ButtonSize = new System.Drawing.Size(48, 48); // no effect
toolbarMain.ImageList = toolbarImages;
toolbarMain.ButtonClick += new ToolBarButtonClickEventHandler(toolbarMain_Click);
Controls.Add(toolbarMain);
#endregion

In just about every winforms application I've written, regardless of language or framework, the toolbar could only be made taller by using larger icons.

You can also put the toolstrip inside a Panel and set the Dock property of the tool strip to Fill. And then you can size the Panel to whatever size you need.