Comments by defunktlemon (Top 36 by date)

seriously?

I ran it - it ran ok and loaded the image. but are the lockpicks and image display linked. they seem separate and unrelated. So, I run the lockpicks ok, but then run the buttonclick as a separate thing.

"better move it to the question where you can format it"

it was in the 'Have a Question or Comment'link. Is that wrong?

yeah cool thanks - so, how do I do that?

hey! how's this Sergey

public Form1()
{
InitializeComponent();
}
private void LockUnlockBitsExample(PaintEventArgs e)
{

Bitmap myImage = new Bitmap("C:\\Users\\jason\\Documents\\IProject\\code\\imageAlign\\imageAlign\\bin\\Debug\\good.jpg");


// Lock the bitmap's bits.
Rectangle rect = new Rectangle(0, 0, myImage.Height, myImage.Width);
System.Drawing.Imaging.BitmapData bmpData =
myImage.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadWrite,
myImage.PixelFormat);

// Get the address of the first line.
IntPtr ptr = bmpData.Scan0;

// Declare an array to hold the bytes of the bitmap.
int bytes = Math.Abs(bmpData.Stride) * myImage.Height;
byte[] rgbValues = new byte[bytes];

// Copy the RGB values into the array.
System.Runtime.InteropServices.Marshal.Copy(ptr, rgbValues, 0, bytes);


// Set every third value to 255. A 24bpp bitmap will look red.
for (int counter = 2; counter < rgbValues.Length; counter += 3)
rgbValues[counter] = 255;


// Copy the RGB values back to the bitmap
System.Runtime.InteropServices.Marshal.Copy(rgbValues, 0, ptr, bytes);

// Unlock the bits.
myImage.UnlockBits(bmpData);

// Draw the modified image.
e.Graphics.DrawImage(myImage, 0, 150);
}

private void button1_Click(object sender, EventArgs e)
{
openFileDialog1.Filter = "JPEG IMAGES|*.jpg";
openFileDialog1.InitialDirectory = "C:\\Users\\jason\\Documents\\IProject\\code\\imageAlign\\imageAlign\\bin\\Debug";
openFileDialog1.Title = "Open Image";
if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
panel1.BackgroundImage = Image.FromFile(openFileDialog1.FileName);
panel1.Invalidate();
}
Bitmap myImage;
myImage = (Bitmap)Image.FromFile(openFileDialog1.FileName);
panel1.BackgroundImage = myImage;

// Array for keeping the sums of each row of pixels
float[] resultArray = new float[myImage.Height];

// Populate the array with data from each row of pixels, using the brightness value
for (int i = 0; i < myImage.Height; i++)
{
float value = 0;
for (int j = 0; j < myImage.Width; j++)
{
value += myImage.GetPixel(j, i).GetBrightness();//get colour of pixel and that Hue-Saturation-Brightness values
}
resultArray[i] = value;
}
}

so, can I go from the lockpixel into a new method to open and draw that image in a panel with a buttonclick method?
like, how do i get to see the image with the rectangle drawn on it from this point?

I think this may be way too advanced for me - i'm just a newbie. Don't you think it is better for a newbie to not worry about performance so much and just use the Get / Set pixels as they are easier?

I have a question about this method Sergey. As stated in the original problem above, I would like for this to scan the image in a few different sections and draw around those sections which have a certain pixel value higher than a threshold set. It is possible to do that with this method, right?

ok. I have gotten the lockbits, or lickbits as you like to call it :), into the program.

But no image loads into the panel? Can I use a panel or should it be picturebox? If I am not mistaken you are not a fan of picturebox as much as get / set pixels :)

you want me to use LockPixels?

Hi OriginalGriff.
If I add your declaration 'Image', I am then declaring a local variable already defined in that scope; as an Image and a Bitmap.
If I comment out the Bitmap declaration it seems ok - but with both of these methods the error on GetPixel (missing using directive or an assembly reference) reappears.

This is how the code looks, which I think is ok. It is after the 'If'statment. Is it wrong? I need the Image declaration as well?
Bitmap myImage;
myImage = (Bitmap)Image.FromFile(openFileDialog1.Filename);

Also, I can't understand your last comment -
"I would also recommend that your OpenFileDialog is constructed in the method, and you use a Bitmap as the generic Image does not have a GetPixel method."
OpenFileDialog is actioned after buttonClick1


panel1.BackgroundImage = myImage;

OriginalGriff.
Guess what? I need to change the code you helped me complete to have a slightly different functionality. And, I think you're the best man for the task of helping me achieve that, given that you gave the initial solution. But, as you suggested, this would be better in a new post. Do you have some time in the near future? I can stick a link here to the new problem.

ahh! I understand. Thank you johanne.
I have actually decided to go with the panel option, which has worked out well. At least, until I added some code to get the pixel values which created another problem. But that's another story - one found at the link below, if you're interested ;)
http://www.codeproject.com/Questions/551825/namingplusbackgroundpluspanelplusimage?cmt=403438#cmt2_551825

yes - that has gotten rid of the red. thank you Groover - I have one more error and then I think I can fly :)
for (int j = 0; j < myImage.Width; j++)
{
value += myImage.GetPixel(j, i).GetBrightness();//get colour of pixel and that Hue-Saturation-Brightness values
}
On the GetPixel i'm asked if i'm missing a using directive or an assembly reference - isn't this normally if a namespace is missing?

I decalred it as Bitmap myImage;
All errors left except one - 'use of unasigned local variable myImage'

or should it be - Bitmap myImage = panel1.BackgroundImage(Image.FromFile);

it's not - I don't know what to declare it as. A bitmap - but the image is drawn on background so does that make it a Bitmap, I thought not - I thought if background panel image it was just held in memory.

not today - I'm exhausted as I'm sure you are - but if I have any questions about using that with my bigger plan would you mind if I continued this?

Oh my God!! You are my new best buddy Guru friend for life(however much life you have left)
I can't believe I have finally gotten this working at last(or you have) Been hitting this for weeks and weeks with others trying to help but all have fallen.
I have not had such excellent help on countless forums in all my life. Your responses today were highly detailed and totally committed. You earn a gold star sir - a beer if I could too.
Thank you thank you thank you.
I am your deepest admirer (even if you do have a long pony tail - even longer beard - and see the world in binary as all programmers of your era did.
Thank you sir. :)

also, it has in hte error box the Locals with e {X=29 Y = 14 Button = Left}
marked in red

It didn't make it to the first red dot. The form opened and when I clicked button1 the image loaded with not change in the dots. I then clicked button2 and the yellow arrow appeared over the first red dot - so I guess the paint_event is not hooked up?

I'll probably get arrested for posting too much code here - but just so you know what I have done here is the code from class From1: Form

private void button1_Click(object sender, EventArgs e)
{
openFileDialog1.Filter = "JPEG IMAGES|*.jpg";
openFileDialog1.InitialDirectory = "C:\\Users\\jason\\Documents\\IProject\\code\\imageAlign\\imageAlign\\bin\\Debug";
openFileDialog1.Title = "Open Image";
if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
panel1.BackgroundImage = Image.FromFile(openFileDialog1.FileName);
panel1.Invalidate();
}
}
private List<myrectangle> rects = new List<myrectangle>();
Random r = new Random();
Pen pen = new Pen(Brushes.Red, 2);

private void butAddARectangle_Click(object sender, EventArgs e)
{
Point p = new Point(r.Next(10, 100), r.Next(10, 100));
Size s = new Size(r.Next(10, 50), r.Next(10, 50));
rects.Add(new MyRectangle(p, s));
panel1.Invalidate();
}

private void MyPanel_Paint(object sender, PaintEventArgs e)
{
foreach (MyRectangle mr in rects)
{
mr.Draw(e.Graphics, pen);
}
}

Holy cow!... That really is some rather awesome explaining - I will have to digest that a few times to really get it I think. Greatly appreciated.
I think I have hooked up correctly. Not getting a result but no errors, which is nice.
I have two buttons on the form. The first opens the image in background of panel. The second is now hooked up to butAddRectangle_click - which I believe is correct.
My class code looks like the following:

public class MyRectangle
{
public Rectangle Rect { get; set; }
public MyRectangle(Point p, Size s)
{
Rect = new Rectangle(p, s);
}

//public MyRectangle()
//{
// // TODO: Complete member initialization
//}

public void Draw(Graphics g, Pen p)
{

g.DrawRectangle(p, Rect);
}
}

The second section you wrote is just pasted in my Form1.cs page.

Button 1 opens image ok but nothing happens when button 2 is clicked. Might this be because button two is not related to what the code in button1_click is doing?

I wonder if I should explain what I am trying to do overall to be sure we are on the same page.
After I have opened the image in the background of the form I will scan different sections of it to sum up the pixel values in each section. If the pixel values in each section are above a certain threshold set then the rectangle should be drawn over / around that section highlighting it so that people would know it is above the threshold. Are we still on the right track OriginalGriff?

wow! Now I'm really kazoonked! That is quite a complex piece of code for little ol' me. I have added the first part to the new class created, MyClass (with a capital beginning :))
And the second part you wrote to the 'public partial class Form1 : Form' page.
I need to 'hook them up'. Do you mean call the class - like 'MyRectangle mc = new MyRectangle();'?
Sorry - I'm newbie lemon.

When you say I need to had it context and a suitable pen, do you mean this:
using (Pen sb = new Pen(Color.Red,3))
{
e.Graphics.DrawRectangle(sb, 20, 20, 50, 50);
}
?
Thanks OG

I'm excited now and would like to try and put this into a class :)
I have created a class

<pre lang="c#"> class rectangle
{

private void panel1_Paint(object sender, PaintEventArgs e)
{
using (Pen sb = new Pen(Color.Red, 3))
{
e.Graphics.DrawRectangle(sb, 20, 20, 50, 50);
}</pre>

But don't know what to pass in the method call?

<pre lang="c#">rectangle mc = new rectangle();</pre>

Fantastic!! Yeah, I was kinda doing it wrong - just a bit.
So, when a class level private variable ends it automatically disposes of any resources used?
but I don't need to worry about that with the code as follows?

<pre lang="c#">private void button1_Click(object sender, EventArgs e)
{
//Bitmap newImage;
openFileDialog1.Filter = "JPEG IMAGES|*.jpg";
openFileDialog1.InitialDirectory = "C:\\Users\\jason\\Documents\\IProject\\code\\imageAlign\\imageAlign\\bin\\Debug";
openFileDialog1.Title = "Open Image";
if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
panel1.BackgroundImage = Image.FromFile(openFileDialog1.FileName);
panel1.Invalidate();
}
}
private void panel1_Paint(object sender, PaintEventArgs e)
{
using (Pen sb = new Pen (Color.Red,3))
{
e.Graphics.DrawRectangle(sb, 20, 20, 50, 50);
}
}</pre>

Thanks OringinalGriff - I put it into a button click event and it worked fine.
But, unless I have a picturebox I can't see the drawn rectangle. Does this mean that the pen can't be used in a panel?

ok, I'm a bit lost now. What code have you changed johannesnestler?
I looked at your links Sergey and I don't need anything to work dynamically or interactively on these images. At least, not at this stage.
Let me explain what I am trying to do overall. I have an image which has been thresholded, using Otsu Thresholding found on this website. In this image there are different assets which when corrupted in the image will show up white, the rest of the image being black. I need to scan this image, with the assets in individually marked sections, to find the section location of the defective assets. I then need to draw on the image a box surrounding the section and write some text, probably to a file detailing what the defect is. This is all I need to do with drawing on the image. Could you please advise me on the best approach to achieve this kind of drawing. Thank you.

It certainly does work - thank you johannestler. But it tiles the images again and again. This seems to be because of:
m_picturebox.Dock = DockStyle.Fill;
I changed the .Fill to other options but none give just a single full image.