我正在寻找一个教程，其中描述了如何使用C＃将隐藏文本写入/读取到图像文件中，但不幸的是我发现了关于此的任何好帖子，所以我决定在这里询问这个小技巧。 / p>
假设我有一个名为test.jpg的图像文件，有没有办法写一个隐藏文本，如＆＃34; Hello word＆＃34;到这个文件？我已经阅读了关于图像元数据的内容，我想我应该尝试以某种方式编写这个元数据，但我不知道如何。 如果有人知道该怎么做，请帮助我理解如何做到这一点。 感谢。
答案 0 :(得分：1)
正确的术语是＆＃34; Steganography＆＃34;。
以下文章阐述了隐写术的定义：
隐写术是通过在其他人中嵌入信息来隐藏信息的艺术和科学。隐写术的工作原理是将常规计算机文件中无用或未使用的数据替换为不同的不可见信息。这些隐藏的信息可以是纯文本，密文，甚至是图像
有关隐写术如何运作的逐步说明：
比隐藏更简单。只是通过的像素 图像直到找到8个连续的零。当你路过时，选择 每个像素单元（R，G，B）的LSB并将其附加到空 值。完成此值的8位后，将其转换回 字符，然后将该字符添加到您正在寻找的结果文本中。
示例源代码是::
class SteganographyHelper
{
public enum State
{
Hiding,
Filling_With_Zeros
};
public static Bitmap embedText(string text, Bitmap bmp)
{
// initially, we'll be hiding characters in the image
State state = State.Hiding;
// holds the index of the character that is being hidden
int charIndex = 0;
// holds the value of the character converted to integer
int charValue = 0;
// holds the index of the color element (R or G or B) that is currently being processed
long pixelElementIndex = 0;
// holds the number of trailing zeros that have been added when finishing the process
int zeros = 0;
// hold pixel elements
int R = 0, G = 0, B = 0;
// pass through the rows
for (int i = 0; i < bmp.Height; i++)
{
// pass through each row
for (int j = 0; j < bmp.Width; j++)
{
// holds the pixel that is currently being processed
Color pixel = bmp.GetPixel(j, i);
// now, clear the least significant bit (LSB) from each pixel element
R = pixel.R - pixel.R % 2;
G = pixel.G - pixel.G % 2;
B = pixel.B - pixel.B % 2;
// for each pixel, pass through its elements (RGB)
for (int n = 0; n < 3; n++)
{
// check if new 8 bits has been processed
if (pixelElementIndex % 8 == 0)
{
// check if the whole process has finished
// we can say that it's finished when 8 zeros are added
if (state == State.Filling_With_Zeros && zeros == 8)
{
// apply the last pixel on the image
// even if only a part of its elements have been affected
if ((pixelElementIndex - 1) % 3 < 2)
{
bmp.SetPixel(j, i, Color.FromArgb(R, G, B));
}
// return the bitmap with the text hidden in
return bmp;
}
// check if all characters has been hidden
if (charIndex >= text.Length)
{
// start adding zeros to mark the end of the text
state = State.Filling_With_Zeros;
}
else
{
// move to the next character and process again
charValue = text[charIndex++];
}
}
// check which pixel element has the turn to hide a bit in its LSB
switch (pixelElementIndex % 3)
{
case 0:
{
if (state == State.Hiding)
{
// the rightmost bit in the character will be (charValue % 2)
// to put this value instead of the LSB of the pixel element
// just add it to it
// recall that the LSB of the pixel element had been cleared
// before this operation
R += charValue % 2;
// removes the added rightmost bit of the character
// such that next time we can reach the next one
charValue /= 2;
}
} break;
case 1:
{
if (state == State.Hiding)
{
G += charValue % 2;
charValue /= 2;
}
} break;
case 2:
{
if (state == State.Hiding)
{
B += charValue % 2;
charValue /= 2;
}
bmp.SetPixel(j, i, Color.FromArgb(R, G, B));
} break;
}
pixelElementIndex++;
if (state == State.Filling_With_Zeros)
{
// increment the value of zeros until it is 8
zeros++;
}
}
}
}
return bmp;
}
public static string extractText(Bitmap bmp)
{
int colorUnitIndex = 0;
int charValue = 0;
// holds the text that will be extracted from the image
string extractedText = String.Empty;
// pass through the rows
for (int i = 0; i < bmp.Height; i++)
{
// pass through each row
for (int j = 0; j < bmp.Width; j++)
{
Color pixel = bmp.GetPixel(j, i);
// for each pixel, pass through its elements (RGB)
for (int n = 0; n < 3; n++)
{
switch (colorUnitIndex % 3)
{
case 0:
{
// get the LSB from the pixel element (will be pixel.R % 2)
// then add one bit to the right of the current character
// this can be done by (charValue = charValue * 2)
// replace the added bit (which value is by default 0) with
// the LSB of the pixel element, simply by addition
charValue = charValue * 2 + pixel.R % 2;
} break;
case 1:
{
charValue = charValue * 2 + pixel.G % 2;
} break;
case 2:
{
charValue = charValue * 2 + pixel.B % 2;
} break;
}
colorUnitIndex++;
// if 8 bits has been added,
// then add the current character to the result text
if (colorUnitIndex % 8 == 0)
{
// reverse? of course, since each time the process occurs
// on the right (for simplicity)
charValue = reverseBits(charValue);
// can only be 0 if it is the stop character (the 8 zeros)
if (charValue == 0)
{
return extractedText;
}
// convert the character value from int to char
char c = (char)charValue;
// add the current character to the result text
extractedText += c.ToString();
}
}
}
}
return extractedText;
}
public static int reverseBits(int n)
{
int result = 0;
for (int i = 0; i < 8; i++)
{
result = result * 2 + n % 2;
n /= 2;
}
return result;
}
}
来源文章：http://www.codeproject.com/Tips/635715/Steganography-Simple-Implementation-in-Csharp
答案 1 :(得分：-2)
您也可以参考.. Image Steganography Application C#