This is my First blog in .netindonesia.net. For two days I have training session from Mr. Risman Adnan at Microsoft Innovation Center ITB. He was the one who introduce me on how to join this blog.
I am a using Visual C# .NET to develop an application for my research. The objective of the research is to develop hardware for MPEG-4/H.264 Variable Block Size Motion Estimation. So I will develop algorithm, prove its functionality and then use it as a reference for the hardware design.
In order to achieve my objective, I need something to visualize the result of my algorithm. I choose Visual C# because I can code faster because there’s abundant of information and tutorial on how to use GDI+ using C# and very easy to implement. Codeproject is my primary source for easy to follow tutorials.
I have to made this modules in my application :
- Framereader : to read data from raw image sequences frame by frame (176x144 pixel, QCIF).
- Partitioner : to split the frame into smaller blocks called the Macroblock (16x16 pixel).
- SADEngine : this is the engine of Motion Estimation, I used Sum of Absolute Differences for block matching criteria.
Visualization is made using GDI+, I choose to display everything using the OnPaint() method, so every time I want to refresh the visualization I have to set a flag and call the
Invalidate() method. I don’t know the ‘Best Practice’ for using GDI+ since I didn’t found it, I would really appreciate if anyone could help me on coding for GDI+.
Here’s a part of my code:
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
float brushwidth = 1.5F;
pen = new Pen(Color.White, brushwidth);
SolidBrush colorizer = new SolidBrush(Color.Lime);
graph = panelMainTop.CreateGraphics();
graph2 = panelMainBottom.CreateGraphics();
String Str = "";
Font drawFont = new Font("Arial", 10);
SolidBrush drawBrush = new SolidBrush(Color.Black);
StringFormat drawFormat = new StringFormat();
drawFormat.FormatFlags = StringFormatFlags.NoClip;
//display frames
if(displayFrame)
{
int left1 = 10;
int left2 = 220;
int top = 30;
int topText = 15;
int stepLength = 1;
int width = 1;
int height = 1;
// Create string to draw.
Str = "Reference Frame (-1)";
graph.DrawString(Str, drawFont, drawBrush, left1, topText, drawFormat);
Str = "Current Frame (0)";
graph.DrawString(Str, drawFont, drawBrush, left2, topText, drawFormat);
//create 176x144 picture
for(int i=0;i<144;i++) //144
{
for(int j=0;j<176;j++) //176
{
colorizer.Color =
Color.FromArgb((int)refFrame[i,j],(int)refFrame[i,j],(int)refFrame[i,j]);
graph.FillRectangle(colorizer, left1+(stepLength*j), top+(stepLength*i), width, height);
colorizer.Color = Color.FromArgb(
(int)currFrame[i,j],(int)currFrame[i,j],(int)currFrame[i,j]);
graph.FillRectangle(colorizer,
left2+(stepLength*j),top+(stepLength*i), width, height);
}
}
}
…
Those codes are for displaying a frame into the Form. I have to set the displayFrame to true in order to show the frame. If I want to show something else I have to set other flags.