how can i get all pixels coordinate for shape boundary

Question

hi i need some help here i have an geometry image example diamond with boundary lines without fill i need to get all the black pixels coordinate of the lines. can someone help me to give an ideas and suggestion? thank you so much aznimah

Frogleg · Answer

try this private void bttnSave_Click( object sender EventArgs e) { if (coordinate.Items.Count { MessageBox .Show( Please generate vertices ); return ; } saveFileDialog1.Filter = Text files (*.txt)|*.txt ; if (saveFileDialog1.ShowDialog() == System.Windows.Forms. DialogResult .OK) { using ( StreamWriter sw = new StreamWriter (saveFileDialog1.FileName )) { foreach ( string itm in coordinate.Items) sw.WriteLine(itm); } } }

Frogleg · Answer

Try this

Noor Aznimah Abdul Aziz · Answer

Hi Frogleg thanks for the code ;) you are really great i learn a lot ;) thank you so much ;)

Noor Aznimah Abdul Aziz · Answer

hi i try to save the pixels coordinate from the listbox to txt file here is my code using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Drawing.Drawing2D; using System.Collections; using System.IO; //c corner namespace gettyPixel { public partial class Form1 : Form { private Bitmap OriginalImage; // private Bitmap imgOut; private double BWThresh ; private Color cblack = System.Drawing.Color.FromArgb(255 0 0 0); private Color cwhite = System.Drawing.Color.FromArgb(255 255 255 255); //private ArrayList outList; public Form1() { InitializeComponent(); } private void Form1_Load(object sender EventArgs e) { BWThresh = 0.5; } private void bttnOpen_Click(object sender EventArgs e) { openFileDialog1.Filter = Image Files(*.PNG;*.JPG;*.GIF)|*.PNG;*.JPG;*.GIF; if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK) { pictureBox1.Image = null; Image img = Image.FromFile(openFileDialog1.FileName);// load image OriginalImage = new Bitmap(img.Width img.Height); Graphics g = Graphics.FromImage(OriginalImage);// draw to bitmap g.DrawImage(img 0 0); pictureBox1.Image = Img2BW(OriginalImage BWThresh); } } private void bttnVertex_Click(object sender EventArgs e) { /* display all pixels coordinate in listbox */ ArrayList pxList = scan(OriginalImage); ShowVertexList(pxList); label1.Text = (Listbox1 count =  + coordinate.Items.Count); } /* Convert the image into binary image*/ // --> create a new B/W image from source image with brightness threshold = 0.5 // --> this action is to make sure we only deal with black and white color private Bitmap Img2BW(Bitmap imgSrc double threshold) { int width = imgSrc.Width; int height = imgSrc.Height; int px; double br; Color pixel; Bitmap imgOut = new Bitmap(imgSrc); for (int row = 0; row { for (int col = 0; col { pixel = imgSrc.GetPixel(col row); px = pixel.ToArgb(); br = pixel.GetBrightness(); if (pixel.GetBrightness() imgOut.SetPixel(col row cblack); else imgOut.SetPixel(col row cwhite); } } return imgOut; } /* Show the pixels coordinate in listBox*/ private void ShowVertexList(ArrayList al) { /* * Show the vertex in ListBox */ coordinate.Items.Clear(); Vertex prv; for (int k = 0; k { prv = (Vertex)al[k]; coordinate.Items.Add({ + prv.X.ToString() +  + prv.Y.ToString() + }); } } private ArrayList scan(Bitmap imgSrc) { pictureBox1.Refresh(); Graphics g = pictureBox1.CreateGraphics(); ArrayList pixels = new ArrayList(); for (int j = 0; j { for (int i = 0; i { if (imgSrc.GetPixel(i j) == cblack) { Vertex pix = new Vertex(i j); pixels.Add(pix); if (checkBox1.Checked == false) { g.FillRectangle(Brushes.Red i j 2 2); } } } } return pixels; } private void numericUpDown1_ValueChanged(object sender EventArgs e) { BWThresh = Convert.ToDouble(numericUpDown1.Value); } private void button1_Click(object sender EventArgs e) { saveFileDialog1.ShowDialog(); } private void saveFileDialog1_FileOk(object sender CancelEventArgs e) { if (saveFileDialog1.FileName != ) { StreamWriter sw = new StreamWriter(saveFileDialog1.FileName); sw.WriteLine(coordinate.Items); sw.Close(); } } } } but it does not return any file thanks aznimah

Noor Aznimah Abdul Aziz · Answer

Hi Frogleg i already try it ;) it return all the black pixels coordinate right. thanks for your help on my code. really thank you for your help thank you so much ;)

Noor Aznimah Abdul Aziz · Answer

hi Frogleg thanks for the reply what im trying to do is: 1) load an image 2) convert image to binary image so that the pixels color would be only black and white [0 or 1] 2) get display in listbox all the pixels coordinate which color black [1] only i have try to code earlier but the code is not working here is the code: using System; using System.Collections; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace PixelsCoordinate { public partial class Form1 : Form { private Bitmap OriginalImage; private Bitmap imgOut; private double BWThresh = 0.5; private Color cblack = System.Drawing.Color.FromArgb(255 0 0 0); private Color cwhite = System.Drawing.Color.FromArgb(255 255 255 255); private ArrayList outList; public Form1() { InitializeComponent(); } private void buttonOpen_Click(object sender EventArgs e) { openFileDialog1.FileName = ; openFileDialog1.Title = Images; openFileDialog1.Filter = All Images|*.png; *.bmp; *.png; openFileDialog1.ShowDialog(); if (openFileDialog1.FileName.ToString() != ) { pictureBox1.ImageLocation = openFileDialog1.FileName.ToString(); OriginalImage = new Bitmap(openFileDialog1.FileName.ToString()); } } private void buttonVertex_Click(object sender EventArgs e) { /* * to convert image to binary image and display all pixels coordinate in listbox */ Bitmap imgSrc = new Bitmap(OriginalImage); Bitmap imgOut = new Bitmap(imgSrc.Width imgSrc.Height System.Drawing.Imaging.PixelFormat.Format24bppRgb); // --> create a new B/W image from source image with brightness threshold = 0.5 // --> this action is to make sure we only deal with black and white color imgOut = Img2BW(imgSrc BWThresh); ArrayList pxList = scan(imgOut); ShowVertexList(pxList); } /* Convert the image into binary image*/ private Bitmap Img2BW(Bitmap imgSrc double threshold) { int width = imgSrc.Width; int height = imgSrc.Height; int px; double br; Color pixel; Bitmap imgOut = new Bitmap(imgSrc); for (int row = 0; row { for (int col = 0; col { pixel = imgSrc.GetPixel(col row); px = pixel.ToArgb(); br = pixel.GetBrightness(); if (pixel.GetBrightness() imgOut.SetPixel(col row cblack); else imgOut.SetPixel(col row cwhite); } } return imgOut; } /* Show the pixels coordinate in listBox*/ private void ShowVertexList(ArrayList al) { /* * Show the vertex in ListBox */ Vertex prv; for (int k = 0; k { prv = (Vertex)al[k]; coordinate.Items.Add({ + prv.X.ToString() +  + prv.Y.ToString() + }); } } private ArrayList scan(Bitmap imgSrc) { coordinate.Items.Clear(); Bitmap bp = new Bitmap(imgSrc); ArrayList pixels = new ArrayList(); for (int j = 0; j { for (int i = 0; i { if (bp.GetPixel(i j) == cblack) { Vertex pix = new Vertex(i j); pix.AddPixels(v); } } } return pixels; } //private class Vertex { ArrayList vertices = new ArrayList(); private int x; private int y; public Vertex(int i int j) { this.X = i; this.Y = j; } public void insert(Vertex v) { vertices.Add(v); } public ArrayList GetPixels() { return vertices; } public int GetCount() { return vertices.Count; } public void AddPixels(Vertex v) { vertices.Add(v); } public int X { get { return x; } set { x = value; } } public int Y { get { return y; } set { y = value; } } } } } really need help on this urgently thank you so much aznimah

Frogleg · Answer

you can use Bitmap myBitmap = new Bitmap(yourWidthyourHeight); Color pixelColor = myBitmap.GetPixel(myX myY); int red = pixelColor.R; int blue = pixelColor.B; int green = pixelColor.G; Then loop through myBitmap and check if redblue and green = 0* and if so record myX and myY. *You may need to check value between 0 & 10 to give yourself a bit of leeway