I'm having a difficult time on this issue. I've searched on this site and couldn't find a solution anywhere yet. I have to make a grid of blocks to be displayed on a picture. I've searched and found things about drawing the grid and the GridView class. But all that seems impossible since I have to manipulate the size of the blocks to whatever size. So if anyone can provide any advice I would be very grateful thanks.
If you need simple grid, you can do it by simply drawing it to image:
using (var bitmap = Bitmap.FromFile(#"C:\darbai_test\Penguins.jpg"))
{
var graphics = Graphics.FromImage(bitmap);
var xStep = 10;
var yStep = 15;
for (int i = 0; i < bitmap.Width / xStep; i++)
{
var x = i * xStep;
graphics.DrawLine(Pens.Black, x, 0, x, bitmap.Height);
}
for (int j = 0; j < bitmap.Height / yStep; j++)
{
var y = j * yStep;
graphics.DrawLine(Pens.Black, 0, y, bitmap.Width, y);
}
bitmap.Save(#"c:\darbai_test\penguins_withgrid.jpg");
}
Related
My goal is to have a robot use this grid to create a map base off the information it collects from its surroundings. When the robot detects an object the square in front of it turns red. Currently I am stuck on how I can give each square an x and Y value for location purposes. Also when I scroll the screen the block sizes change, can someone provide help with that as well?
Rectangle rect = new Rectangle(700, 350, 50, 50);
g.DrawRectangle(myPen, rect); // Draws the Rectangle to the screen
e.Graphics.FillEllipse(myBrush, 700,350,50,50);`
for (int i = 0; i < 9900; i = i + 50)
{
rect = new Rectangle(0 + i, 0, 50, 50);
g.DrawRectangle(myPen, rect);
for (int j = 0; j < 9900; j = j + 50)
{
rect = new Rectangle(0 + i, 0 + j, 50, 50);
g.DrawRectangle(myPen, rect);
}
}
Here is a very quick example of how to do this using a 2d array. It was written in LINQPad, so it may look a little odd, but it should give you some leads. It allows you to store a map and look up values using x and y coordinates. You can use the CellInfo class to add any extra information about the cell that you need, beyond if it is blocking or not.
Ideally, you would want to wrap the entire array up in your own Map class, that abstracts away the details, and gives you a lot of helpful utility functions. For instance, if your map is extremely large, you may run out of memory. You could have the Map class only load smaller blocks of the map from files on disk as needed, or even make the map wrap around its self easily.
void Main()
{
var map = new CellInfo[10, 10];
for (int x = 0; x < 10; x++)
{
for (int y = 0; y < 10; y++)
{
map[x, y] = new CellInfo();
}
}
var rnd = new Random();
for (int i = 0; i < 20; i++)
{
map[rnd.Next(0, 10), rnd.Next(0, 10)].IsBlocked = true;
}
DrawMap(map).Dump();
}
public Bitmap DrawMap(CellInfo[,] map)
{
var img = new Bitmap(320, 320, PixelFormat.Format32bppArgb);
using (var g = Graphics.FromImage(img))
{
for (int x = 0; x < 10; x++)
{
for (int y = 0; y < 10; y++)
{
var cell = map[x, y];
Brush brush = cell.IsBlocked ? Brushes.Red : Brushes.White;
g.FillRectangle(brush, x * 32, y * 32, 31, 31);
g.DrawRectangle(Pens.Black, x * 32, y * 32, 31, 31);
}
}
}
return img;
}
public class CellInfo
{
public bool IsBlocked { get; set; } = false;
}
It produces the following output (varies each time it is run):
I need to mirror an image and display it like this:
To display like this:
This is my code so far, I have had no luck:
int Height = TransformedPic.GetLength(0);
int Width = TransformedPic.GetLength(1);
for (int i = 0; i < Height; i++)//loop rows
{
for (int j = 0; j < Width; j++)//loop columns
{
TransformedPic[i, j] = TransformedPic[i, ((2 * Width) - (j + 1))];
}
}
Image.RotateFlip will do the job at lot faster and easier:
Bitmap bmp1 = (Bitmap)pictureBox1.Image;
Bitmap bmp2 = new Bitmap(bmp1.Width * 2, bmp1.Height);
using (Graphics G = Graphics.FromImage(bmp2))
{
G.DrawImage(bmp1, 0, 0);
bmp1.RotateFlip(RotateFlipType.RotateNoneFlipX);
G.DrawImage(bmp1, bmp1.Width, 0);
pictureBox2.Image = bmp2;
}
Instead you could use loops similar to yours and Bitmap.GetPixel and Bitmap.SetPixel but that would be really slow:
TransformedPic.SetPixel(Width - i, j, TransformedPic.GetPixel(i,j));
Going over one half of the width..
Or you could do it like this in one line:
picBox.Image.RotateFlip(RotateFlipType.RotateNoneFlipX)
My code seems to compile okay, but when I try to run it, it hangs very badly.
I've been following along with Riemers XNA tutorial here.
I'm pretty familiar with C#, but an expert by no means. I've had no problems getting any of this to work up to this point, and there are no errors or exceptions being thrown... it just hangs up. I've read on his related forum, where users discussed having other problems, usually relating to typos or code errors, but there's nothing like this in there... everyone seems to be able to run it fine.
Is there something I've done wrong perhaps? The nested for-loop at the bottom seems a bit heavy-handed to me. screenWidth and screenHeight are 500 and 500.
BTW: this is run from the LoadContent override method, so it should only run once as far as I know.
private void GenerateTerrainContour()
{
terrainContour = new int[screenWidth];
for (int x = 0; x < screenWidth; x++)
terrainContour[x] = screenHeight / 2;
}
private void CreateForeground()
{
Color[] foregroundColors = new Color[screenWidth * screenHeight];
for (int x = 0; x < screenWidth; x++)
{
for (int y = 0; y < screenHeight; y++)
{
if (y > terrainContour[x])
foregroundColors[x + y * screenWidth] = Color.Green;
else
foregroundColors[x + y * screenWidth] = Color.Transparent;
fgTexture = new Texture2D(device, screenWidth, screenHeight, false, SurfaceFormat.Color);
fgTexture.SetData(foregroundColors);
}
}
}
Probably something to do with the fact that you're creating 250,000 screen sized textures (holy moly)!
Resource allocation is always heavy - especially when you're dealing with media such as sounds and images.
It seems like you only really need one texture here, try moving fgTexture = new Texture2D(device, screenWidth, screenHeight, false, SurfaceFormat.Color); outside of the loop. Then try moving fgTexture.SetData(foregroundColors); outside of the loop too.
private void CreateForeground()
{
Color[] foregroundColors = new Color[screenWidth * screenHeight];
fgTexture = new Texture2D(device, screenWidth, screenHeight, false, SurfaceFormat.Color);
for (int x = 0; x < screenWidth; x++)
{
for (int y = 0; y < screenHeight; y++)
{
if (y > terrainContour[x])
foregroundColors[x + y * screenWidth] = Color.Green;
else
foregroundColors[x + y * screenWidth] = Color.Transparent;
}
}
fgTexture.SetData(foregroundColors);
}
for (int x = 0; x < screenWidth; x++)
{
for (int y = 0; y < screenHeight; y++)
{
if (y > terrainContour[x])
foregroundColors[x + y * screenWidth] = Color.Green;
else
foregroundColors[x + y * screenWidth] = Color.Transparent;
}
}
foregroundTexture = new Texture2D(device, screenWidth, screenHeight, false, SurfaceFormat.Color);
foregroundTexture.SetData(foregroundColors);
Your issue is on the last two lines. In your loop, you're creating 500 x 500 Texture2D objects, which is slowing you down. Move them outside the for loop.
Sorry for the previous post. I now show the full code here.
I need to know what the bitmap.Width and bitmap.Height - 1 for and also the bitmap.Scan0.
I search in the internet but it does not give any full explanation for that.
I will appreciate anyone who can briefly explain the whole thing. Thank you.
public static double[][] GetRgbProjections(Bitmap bitmap)
{
var width = bitmap.Width - 1;
var height = bitmap.Height - 1;
var horizontalProjection = new double[width];
var verticalProjection = new double[height];
var bitmapData1 = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
unsafe
{
var imagePointer1 = (byte*)bitmapData1.Scan0;
for (var y = 0; y < height; y++)
{
for (var x = 0; x < width; x++)
{
var blu = imagePointer1[0];
var green = imagePointer1[1];
var red = imagePointer1[2];
int luminosity = (byte)(((0.2126 * red) + (0.7152 * green)) + (0.0722 * blu));
horizontalProjection[x] += luminosity;
verticalProjection[y] += luminosity;
imagePointer1 += 4;
}
imagePointer1 += bitmapData1.Stride - (bitmapData1.Width * 4);
}
}
MaximizeScale(ref horizontalProjection, height);
MaximizeScale(ref verticalProjection, width);
var projections =
new[]
{
horizontalProjection,
verticalProjection
};
bitmap.UnlockBits(bitmapData1);
return projections;
}
Apparently it runs through every pixel of a RGBA bitmap and calculates the luminosity per pixel which its tracks inside two arrays, luminosity per horizontal line and luminosity per vertical line.
Unless I am mistaken, the -1 should not even be there. When you have a bitmap of 100x100 you want to create an array with 100 elements, not an array with 99 elements (width-1) since you want to track every horizontal and vertical line.
Hello friends am trying to apply 3x3 median filter to fingerprint image of appxo 500x500.
I am using pointers to acess the image data. But i realy cant figure out how to do it. I know the concept very well, but if u guyz help me out in code it will be great help. I searched on net, but i dint get any help. thank you
public void medianfilter(Bitmap image)
{
Byte[,] rtemp = new Byte[3, 3];
Byte[,] gtemp = new Byte[3, 3];
Byte[,] btemp = new Byte[3, 3];
BitmapData data = image.LockBits(new Rectangle(0, 0, image.Width, image.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
int stride = data.Stride;
unsafe {
byte* imgPtr = (byte*)(void*)(data.Scan0);
int nOffset = stride - image.Width * 3;
for (int i = 0; i < image.Width; i++)
{
for (int j = 0; j < image.Height; j++)
{
for (int x = i; x < 3 + i; x++)
{
for (int y = j; y < 3 + j; y++) {
rtemp[x, y] = imgPtr[0];
gtemp[x, y] = imgPtr[1];
btemp[x, y] = imgPtr[2];
imgPtr += 3; } } imgPtr += nOffset;
}
}
}
}
First of all you are not modifying the Bitmap at all!
You need to dereference the pointer before to apply the change and then you have to UNLOCK the bitmap...
Here's what I had in my old computer graphics course. Modify it as needed.
unsafe
{
//Go to first pixel, the cast is important
byte* p = (byte*)imageData.Scan0.ToPointer();
//For each line
for (int y = 0; y < bmp.Height; y++)
{
//For each pixel (bmp.Width * 3) because jpg has R, G, and B value if the bitmap has an alpha do a *4 multiplier
for (int x = 0; x < bmp.Width * 3; x++)
{
//Invert from the original image
*p = (byte)(255 - *p);
//Go to next pointer
p++;
}
//Move pointer to the right end of the line and then go down to a new line
//Skip the unused space
p += offset;
}
}
bmp.UnlockBits(imageData);
bmp.Save(path);
Hope it helps!