code explanation

Question

i need the explanation of this code which is written below

 loadedTrueImagePath = openFileDialog1.FileName;

                EnImage_tbx.Text = loadedTrueImagePath;

                loadedTrueImage = Image.FromFile(loadedTrueImagePath);

                height = loadedTrueImage.Height;

                width = loadedTrueImage.Width;

                loadedTrueBitmap = newBitmap(loadedTrueImage);

 

                FileInfoimginf = newFileInfo(loadedTrueImagePath);

                floatfs = (float)imginf.Length / 1024;

                ImageSize_lbl.Text = smalldecimal(fs.ToString(), 2) + " KB";

                ImageHeight_lbl.Text = loadedTrueImage.Height.ToString() + " Pixel";

Answer 1

1. loadedTrueImagePath = openFileDialog1.FileName; ----------------------> Get the file name selected from OpenFileDialog

2. EnImage_tbx.Text = loadedTrueImagePath; ------------------------------> Strore the file name in control named EnImage_tbx

3. oadedTrueImage = Image.FromFile(loadedTrueImagePath);------------> Create an Image object from the file selected

4. height = loadedTrueImage.Height;------------------------------------------> Get the height of the image and store it in height variable

5. width = loadedTrueImage.Width;---------------------------------------------> Get the Width of the image and store it in width variable

6. loadedTrueBitmap = newBitmap(loadedTrueImage);-----------------------> Create a Bitmap object from the image create in Step 3

 

7.  FileInfoimginf = newFileInfo(loadedTrueImagePath);--------------------- > Create FileInfo object from the image in step 3.

8. floatfs = (float)imginf.Length / 1024;----------------------------------------> Get the size of the file in Kilo Bytes

9. ImageSize_lbl.Text = smalldecimal(fs.ToString(), 2) + " KB";------------- > Display the size of the file in KiloBytes on Label named ImageSize_lbl.

10. ImageHeight_lbl.Text = loadedTrueImage.Height.ToString() + " Pixel";-> Display the height of the file in pixels on Label named ImageHeight_lbl.

I hope this helps.

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Please mark this post as answer if it solved your problem. Happy Programming!

Answer 2

I need the explanation of the code which is written below

FileInfo imginf = new FileInfo(loadedTrueImagePath);

                floatfs = (float)imginf.Length / 1024;

                ImageSize_lbl.Text = smalldecimal(fs.ToString(), 2) + " KB";

                ImageHeight_lbl.Text = loadedTrueImage.Height.ToString() + " Pixel";

                ImageWidth_lbl.Text = loadedTrueImage.Width.ToString() + " Pixel";

                doublecansave = (8.0 * ((height * (width / 3) * 3) / 3 - 1)) / 1024;

                CanSave_lbl.Text = smalldecimal(cansave.ToString(), 2) + " KB";

 

                canPaint = true;

                this.Invalidate();

            }

        }

 

        privatestringsmalldecimal(stringinp, intdec)

        {

            inti;

            for(i = inp.Length - 1; i > 0; i--)

                if(inp[i] == '.')

                    break;

            try

            {

                returninp.Substring(0, i + dec + 1);

            }

            catch

            {

                returninp;

            }

        }

 

        privatevoidEnFileBrowse_btn_Click(objectsender, EventArgse)

        {

            if(openFileDialog2.ShowDialog() == DialogResult.OK)

            {

                loadedFilePath = openFileDialog2.FileName;

                EnFile_tbx.Text = loadedFilePath;

                FileInfofinfo = newFileInfo(loadedFilePath);

                fileSize = finfo.Length;

                fileNameSize = justFName(loadedFilePath).Length;

            }

        }

 

Answer 3

  I need the explanation of this code for encryption  which is written below:

        privatevoidEncryptLayer()

        {

            toolStripStatusLabel1.Text ="Encrypting... Please wait";

            Application.DoEvents();

            longFSize = fileSize;

            BitmapchangedBitmap = EncryptLayer(8, loadedTrueBitmap, 0, (height * (width/3)*3) / 3 - fileNameSize - 1, true);

            FSize -= (height * (width / 3) * 3) / 3 - fileNameSize - 1;

            if(FSize > 0)

            {

                for(inti = 7; i >= 0 && FSize > 0; i--)

                {

                    changedBitmap = EncryptLayer(i, changedBitmap, (((8 - i) * height * (width / 3) * 3) / 3 - fileNameSize - (8 - i)), (((9 - i) * height * (width / 3) * 3) / 3 - fileNameSize - (9 - i)), false);

                    FSize -= (height * (width / 3) * 3) / 3 - 1;

                }

            }

            changedBitmap.Save(saveToImage);

            toolStripStatusLabel1.Text = "Encrypted image has been successfully saved.";

            EncriptionDone = true;

            AfterEncryption = Image.FromFile(saveToImage);

            this.Invalidate();

        }

 

 

        privateBitmapEncryptLayer(intlayer, BitmapinputBitmap, longstartPosition, longendPosition, boolwriteFileName)

        {

            BitmapoutputBitmap = inputBitmap;

            layer--;

            inti = 0, j = 0;

            longFNSize = 0;

            bool[] t = newbool[8];

            bool[] rb = newbool[8];

            bool[] gb = newbool[8];

            bool[] bb = newbool[8];

            Colorpixel = newColor();

            byter, g, b;

 

            if(writeFileName)

            {

                FNSize = fileNameSize;

                stringfileName = justFName(loadedFilePath);

 

                //write fileName:

                for(i = 0; i < height && i * (height / 3) < fileNameSize; i++)

                    for(j = 0; j < (width / 3) * 3 && i * (height / 3) + (j / 3) < fileNameSize; j++)

                    {

                        byte2bool((byte)fileName[i * (height / 3) + j / 3], reft);

                        pixel = inputBitmap.GetPixel(j, i);

                        r = pixel.R;

                        g = pixel.G;

                        b = pixel.B;

                        byte2bool(r, refrb);

                        byte2bool(g, refgb);

                        byte2bool(b, refbb);

                        if(j % 3 == 0)

                        {

                            rb[7] = t[0];

                            gb[7] = t[1];

                            bb[7] = t[2];

                        }

                        elseif(j % 3 == 1)

                        {

                            rb[7] = t[3];

                            gb[7] = t[4];

                            bb[7] = t[5];

                        }

                        else

                        {

                            rb[7] = t[6];

                            gb[7] = t[7];

                        }

                        Colorresult = Color.FromArgb((int)bool2byte(rb), (int)bool2byte(gb), (int)bool2byte(bb));

                        outputBitmap.SetPixel(j, i, result);

                    }

                i--;

            }

            //write file (after file name):

            inttempj = j;

 

            for(; i < height && i * (height / 3) < endPosition - startPosition + FNSize && startPosition + i * (height / 3) < fileSize + FNSize; i++)

                for(j = 0; j < (width / 3) * 3 && i * (height / 3) + (j / 3) < endPosition - startPosition + FNSize && startPosition + i * (height / 3) + (j / 3) < fileSize + FNSize; j++)

                {

                    if(tempj != 0)

                    {

                        j = tempj;

                        tempj = 0;

                    }

                    byte2bool((byte)fileContainer[startPosition + i * (height / 3) + j / 3 - FNSize], reft);

                    pixel = inputBitmap.GetPixel(j, i);

                    r = pixel.R;

                    g = pixel.G;

                    b = pixel.B;

                    byte2bool(r, refrb);

                    byte2bool(g, refgb);

                    byte2bool(b, refbb);

                    if(j % 3 == 0)

                    {

                        rb[layer] = t[0];

                        gb[layer] = t[1];

                        bb[layer] = t[2];

                    }

                    elseif(j % 3 == 1)

                    {

                        rb[layer] = t[3];

                        gb[layer] = t[4];

                        bb[layer] = t[5];

                    }

                    else

                    {

                        rb[layer] = t[6];

                        gb[layer] = t[7];

                    }

                    Colorresult = Color.FromArgb((int)bool2byte(rb), (int)bool2byte(gb), (int)bool2byte(bb));

                    outputBitmap.SetPixel(j, i, result);

 

                }

            longtempFS = fileSize, tempFNS = fileNameSize;

            r = (byte)(tempFS % 100);

            tempFS /= 100;

            g = (byte)(tempFS % 100);

            tempFS /= 100;

            b = (byte)(tempFS % 100);

            ColorflenColor = Color.FromArgb(r,g,b);

            outputBitmap.SetPixel(width - 1, height - 1, flenColor);

 

            r = (byte)(tempFNS % 100);

            tempFNS /= 100;

            g = (byte)(tempFNS % 100);

            tempFNS /= 100;

            b = (byte)(tempFNS % 100);

            ColorfnlenColor = Color.FromArgb(r,g,b);

            outputBitmap.SetPixel(width - 2, height - 1, fnlenColor);

 

            returnoutputBitmap;

        }

Answer 4

plz explanation this code....... i need it........

Answer 5

Hello Swati,

private string smalldecimal(string inp, int dec)
        {
            int i;
            for(i = inp.Length - 1; i > 0; i--)

                if(inp[i] == '.')

                    break;
            try
            {
                return inp.Substring(0, i + dec + 1);
            }
            catch
            {
                return inp;
            }
        }

this function make "Roundingdecimals" as following

smalldecimal("10.111",2) = "10.11"

smalldecimal("11.235",1) = "11.2"

smalldecimal("12",3) = "12"

smalldecimal("10.111",0) = "10."

private void EnFileBrowse_btn_Click(objectsender, EventArgse)
        {
            if(openFileDialog2.ShowDialog() == DialogResult.OK)
            {
                loadedFilePath = openFileDialog2.FileName;
                EnFile_tbx.Text = loadedFilePath;
                FileInfofinfo = newFileInfo(loadedFilePath);
                fileSize = finfo.Length;
                fileNameSize = justFName(loadedFilePath).Length;
            }
        }

this is the handler of Browse button which show "OpenFileDialog" to get file & show it's data in TextBox "EnFile_tbx" & get some else data.

FileInfo imginf = new FileInfo(loadedTrueImagePath);

                floatfs = (float)imginf.Length / 1024;

                ImageSize_lbl.Text = smalldecimal(fs.ToString(), 2) + " KB";

                ImageHeight_lbl.Text = loadedTrueImage.Height.ToString() + " Pixel";

                ImageWidth_lbl.Text = loadedTrueImage.Width.ToString() + " Pixel";

                doublecansave = (8.0 * ((height * (width / 3) * 3) / 3 - 1)) / 1024;

                CanSave_lbl.Text = smalldecimal(cansave.ToString(), 2) + " KB";

                canPaint = true;

                this.Invalidate();

            }

        }

this function too make some operations to get some data about file.

Answer 6

Can`t be a better explanation. Well done Adavesh :)

---

Mitja

Answer 7

Can`t be a better explanation. Well done Adavesh :)

---

Mitja

:)  Thanks Mitja.

---

Please mark this post as answer if it solved your problem. Happy Programming!

Answer 8

thanx it's a little bit helpful, i need some more explanations of last where functions make operations........

Answer 9

Hi swati88,

Welcome to the MSDN forum!

I'm trying to explain the code as follow:

         private void EncryptLayer()
        {
            toolStripStatusLabel1.Text ="Encrypting... Please wait";
            
            // Processes all Windows messages currently in the message queue. 
            //http://msdn.microsoft.com/en-us/library/system.windows.forms.application.doevents.aspx
            Application.DoEvents();

            long FSize = fileSize; // Get the file size.

             // Encrpt the loaded bitmap.
             // Call the 
             // private Bitmap EncryptLayer(int layer, Bitmap inputBitmap, long startPosition, long endPosition, bool writeFileName)
             // method.
            Bitmap changedBitmap = EncryptLayer(8, loadedTrueBitmap, 0, (height * (width/3)*3) / 3 - fileNameSize - 1, true);

            FSize -= (height * (width / 3) * 3) / 3 - fileNameSize - 1;
            if(FSize > 0)
            {
                for(int i = 7; i >= 0 && FSize > 0; i--)
                {
                    changedBitmap = EncryptLayer(i, changedBitmap, (((8 - i) * height * (width / 3) * 3) / 3 - fileNameSize - (8 - i)), (((9 - i) * height * (width / 3) * 3) / 3 - fileNameSize - (9 - i)), false);
                    FSize -= (height * (width / 3) * 3) / 3 - 1;
                }
            }
            changedBitmap.Save(saveToImage);
            toolStripStatusLabel1.Text = "Encrypted image has been successfully saved.";
            EncriptionDone = true;
            AfterEncryption = Image.FromFile(saveToImage);
            
            // Refresh the UI.
            this.Invalidate();
        }
 
 
        private Bitmap EncryptLayer(int layer, Bitmap inputBitmap, long startPosition, long endPosition, bool writeFileName)
        {
            // The Bitmap to be encrypted.
            Bitmap outputBitmap = inputBitmap;
            layer--;
            int i = 0, j = 0;
            long FNSize = 0;
            bool[] t = new bool[8];
            bool[] rb = new bool[8];
            bool[] gb = new bool[8];
            bool[] bb = new bool[8];
            Color pixel = new Color();
            byte r, g, b;
            
            if(writeFileName)
            {
                FNSize = fileNameSize;
                string fileName = justFName(loadedFilePath);
 
                //write fileName:
                for(i = 0; i < height && i * (height / 3) < fileNameSize; i++)
                    for(j = 0; j < (width / 3) * 3 && i * (height / 3) + (j / 3) < fileNameSize; j++)
                    {
                        // Based on my understanding, it seems to get the R, G, B information 
                        // from the origin bitmap.
                        #region  
                        byte2bool((byte)fileName[i * (height / 3) + j / 3], ref t);
                        pixel = inputBitmap.GetPixel(j, i);
                        r = pixel.R;
                        g = pixel.G;
                        b = pixel.B;
                        byte2bool(r, ref rb);
                        byte2bool(g, ref gb);
                        byte2bool(b, ref bb);
                        #endregion 

                        // Encrypt the RGB info.
                        if (j % 3 == 0)
                        {
                            rb[7] = t[0];
                            gb[7] = t[1];
                            bb[7] = t[2];
                        }
                        else
                            if(j % 3 == 1)
                            {
                                rb[7] = t[3];
                                gb[7] = t[4];
                                bb[7] = t[5];
                            }
                            else
                            {
                                rb[7] = t[6];
                                gb[7] = t[7];
                            }
                        Color result = Color.FromArgb((int)bool2byte(rb), (int)bool2byte(gb), (int)bool2byte(bb));
                        outputBitmap.SetPixel(j, i, result);
                    }
                i--;
            }

            //write file (after file name):
            int tempj = j;
 
            for(; i < height && i * (height / 3) < endPosition - startPosition + FNSize && startPosition + i * (height / 3) < fileSize + FNSize; i++)
                for(j = 0; j < (width / 3) * 3 && i * (height / 3) + (j / 3) < endPosition - startPosition + FNSize && startPosition + i * (height / 3) + (j / 3) < fileSize + FNSize; j++)
                {
                    if(tempj != 0)
                    {
                        j = tempj;
                        tempj = 0;
                    }
                    byte2bool((byte)fileContainer[startPosition + i * (height / 3) + j / 3 - FNSize], reft);
                    pixel = inputBitmap.GetPixel(j, i);
                    r = pixel.R;
                    g = pixel.G;
                    b = pixel.B;
                    byte2bool(r, refrb);
                    byte2bool(g, refgb);
                    byte2bool(b, refbb);
                    if(j % 3 == 0)
                    {
                        rb[layer] = t[0];
                        gb[layer] = t[1];
                        bb[layer] = t[2];
                    }
                    else
                        if(j % 3 == 1)
                        {
                            rb[layer] = t[3];
                            gb[layer] = t[4];
                            bb[layer] = t[5];
                        }
                        else
                        {
                            rb[layer] = t[6];
                            gb[layer] = t[7];
                        }
                    Colorresult = Color.FromArgb((int)bool2byte(rb), (int)bool2byte(gb), (int)bool2byte(bb));
                    outputBitmap.SetPixel(j, i, result);
 
                }
            long tempFS = fileSize, tempFNS = fileNameSize;
            r = (byte)(tempFS % 100);
            tempFS /= 100;
            g = (byte)(tempFS % 100);
            tempFS /= 100;
            b = (byte)(tempFS % 100);
            Color flenColor = Color.FromArgb(r,g,b);
            outputBitmap.SetPixel(width - 1, height - 1, flenColor);
 
            r = (byte)(tempFNS % 100);
            tempFNS /= 100;
            g = (byte)(tempFNS % 100);
            tempFNS /= 100;
            b = (byte)(tempFNS % 100);
            Color fnlenColor = Color.FromArgb(r,g,b);
            outputBitmap.SetPixel(width - 2, height - 1, fnlenColor);
 
            return outputBitmap;
        }

Also, if you want to look into how these encryption are processed, I suggest you look into the structure of the Bitmap:

Bitmap Structures
http://msdn.microsoft.com/en-us/library/dd183392(v=vs.85).aspx

Meanwhile, when I not sure about the code, I usually debug the code step by step, and using "Add Watch" window to watch the variables, and in most cases, it works for me.

Hope it helps and have a nice day!

yoyo

---

Yoyo Jiang[MSFT]
MSDN Community Support | Feedback to us

Answer 10

I can't understand the operation and plz tell me why we use layers for encru\yption in this?

---

swati mishra

Answer 11

i can't understand the operation and tell me why we use 8 layers in encryption..........

---

swati mishra

Answer 12

Hi swati,

IMHO, the operation encrypts the filename and the file into the bitmap. It encrypts the information into the bitmap line by line from width aspect.

For the layers part, based on my understanding, the layers here is just for increasing the complexity of the encryption. 

What is more, since there is “layer--” in the encryption part, I think the following part:

                for(int i = 7; i >= 0 && FSize > 0; i--)
                {
                    changedBitmap = EncryptLayer(i, changedBitmap, (((8 - i) * height * (width / 3) * 3) / 3 - fileNameSize - (8 - i)), (((9 - i) * height * (width / 3) * 3) / 3 - fileNameSize - (9 - i)), false);
                    FSize -= (height * (width / 3) * 3) / 3 - 1;
                }

should be 

               for(int i = 7; i >1 && FSize > 0; i--)
                {
                    changedBitmap = EncryptLayer(i, changedBitmap, (((8 - i) * height * (width / 3) * 3) / 3 - fileNameSize - (8 - i)), (((9 - i) * height * (width / 3) * 3) / 3 - fileNameSize - (9 - i)), false);
                    FSize -= (height * (width / 3) * 3) / 3 - 1;
                }

Otherwise, there may be an index overflow exception when the i=0. 

Hope it helps.
Have a nice day!

yoyo

---

Yoyo Jiang[MSFT]
MSDN Community Support | Feedback to us

Answer 13

how we find the value of r and why we use tempFS

r = (byte)(tempFS % 100);
            tempFS /= 100;

---

swati mishra

Answer 14

            long tempFS = fileSize, tempFNS = fileNameSize;
            r = (byte)(tempFS % 100);
            tempFS /= 100;
            g = (byte)(tempFS % 100);
            tempFS /= 100;
            b = (byte)(tempFS % 100);
            Color flenColor = Color.FromArgb(r,g,b);
            outputBitmap.SetPixel(width - 1, height - 1, flenColor); 

I think here, it just encrypts the file size information into the bitmap, since tempFS = fileNameSize at the beginning.

r = (byte)(tempFNS%100); 

Here, % operator is remainder operator. It gets the remainder of (tempFNS/100), and convert the result to byte, then assign it to r.

Then tempFNS/=100; meaning tempFNS = tempFNS/100; then it get the value of g in the same way. Then it is the value of b. In the end, it set the color using the rgb of the (width -1, height -1) pixel.

Hope it helps.

---

Yoyo Jiang[MSFT]
MSDN Community Support | Feedback to us

Answer 15

in  encryption we use the key to encrypt message , what is that key and how we encrypt the message in this and as u say layers are used to increase the complexity but how it encrypt?

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swati mishra

Answer 16

Hi swati,

I'd like to take the layer here as the key, since I think the key is used for encryption and decryption. You asked "how we encrypt the message in this". For this, I have to mention that the way is showed in the EncryptLayer method. It used the writeFileName parameter to specify whether the FileName should be encrypt. After encrypting the FileName, it encrypt the data in the file, namely the message you mentioned in the last post. 

I suggest you try to contact the author of the code for further discussion about this encryption approach.

Have a nice day!

yoyo

---

Yoyo Jiang[MSFT]
MSDN Community Support | Feedback to us

Answer 17

Hi swati,

I temporarily mark some replies as answers and you can unmark them if they provides no help.

I will keep an eye on the thread in the future. If you have any questions, please feel free to let us know.

Thanks for your understanding and have a nice day!

yoyo

---

Yoyo Jiang[MSFT]
MSDN Community Support | Feedback to us

Answer 18

thanx..........

---

swati mishra

Answer 19

Hi.. I have a small doubt here. Can i know to choose only the text or document file to encrypt it. Because in this coding, we can choose any type of file even the image file to be encrypted. Can you help me to solve it.

Thank you.