位图来自十六进制字符串的图像 - 正在添加的额外字节 [英] Bitmap Image from Hex string - extra bytes being added
问题描述
我有一个来自postscript文件的十六进制字符串。
< / 1将ImageType
/宽度986 /身高1
/ BitsPerComponent 8
/解码[0 1 0 1 0 1]
/ ImageMatrix [986 0 0 -1 0 1]
/ DataSource<
803fe0503824160d0784426150b864361d0f8844625138a4562d178c466351b8e4763d1f904864523924964d27944a6552b964b65d2f984c665339a4d66d379c4e6753b9e4f67d3fa05068543a25168d47a4526954ba648202
> / LZWDecode filter>> image}下面是我使用的方法。下面是我使用的方法。我注释掉更新颜色的方法。 公共静态无效ProcessImageColourMapping（）
{
串imageDataSource =803fe0503824160d0784426150b864361d0f8844625138a4562d178c466351b8e4763d1f904864523924964d27944a6552b964b65d2f984c665339a4d66d379c4e6753b9e4f67d3fa05068543a25168d47a4526954ba648202;
string imageDataSourceUpdated = GetUpdatedImage（imageDataSource）;
}
公共静态字符串GetUpdatedImage（字符串strImageDataSource）
{
串imageDataSourceUpdated =;
byte [] imageBytes = StringToByteArray（strImageDataSource）;
Bitmap bitmapImage = ByteArrayToBitmap（imageBytes）;
// UpdateColour（bitmapImage）;
byte [] imageBytesUpdated = BitmapToByteArray（bitmapImage）;
imageDataSourceUpdated = ByteArrayToString（imageBytesUpdated）;
return imageDataSourceUpdated;
}
public static byte [] StringToByteArray（String imageHexString）
{
int numberOfChars = imageHexString.Length / 2;
byte [] byteArray = new byte [numberOfChars];
using（var sr = new StringReader（imageHexString））
{
for（int i = 0; i
}
return byteArray;
}
public static Bitmap ByteArrayToBitmap（byte [] byteArray）
{
int width = 986; //宽度和高度取自postscript文件，用于测试单个十六进制字符串。
int height = 1;
Bitmap bitmapImage = new Bitmap（width，height，PixelFormat.Format32bppPArgb）;
BitmapData bmpData = bitmapImage.LockBits（new Rectangle（0，0，width，height），ImageLockMode.ReadWrite，PixelFormat.Format32bppPArgb）;
try
{
Marshal.Copy（byteArray，0，bmpData.Scan0，byteArray.Length）;
}
finally
{
bitmapImage.UnlockBits（bmpData）;
}
return bitmapImage;
}
public static byte [] BitmapToByteArray（Bitmap bitmap）
{
BitmapData bmpdata = bitmap.LockBits（new Rectangle（0，0，bitmap.Width， bitmap.Height），ImageLockMode.ReadOnly，bitmap.PixelFormat）;
int numbytes = bmpdata.Stride * bitmap.Height;
byte [] bytedata = new byte [numbytes];
try
{
Marshal.Copy（bmpdata.Scan0，bytedata，0，numbytes）;
}
finally
{
bitmap.UnlockBits（bmpdata）;
}
return bytedata;
}
public static string ByteArrayToString（byte [] byteArray）
{
StringBuilder hex = new StringBuilder（byteArray.Length * 2）;
foreach（byteArray中的字节b）
{
hex.AppendFormat（{0：x2}，b）;
}
return hex.ToString（）;
}
问题：
在下面的代码中，我没有更新任何东西进来的十六进制字符串 imageDataSource 。
将其转换为byte [] - 然后到位图 - 返回字节[ ] - 最后回到十六进制字符串。
所以， imageDataSourceUpdated 应该与 imageDataSource 。
但是，当我最终检查 imageDataSourceUpdated 的值时，它显示为：
803fe0503824160d0784426150b864361d0f8844625138a4562d178c466351b8e4763d1f904864523924964d27944a6552b964b65d2f984c665339a4d66d379c4e6753b9e4f67d3fa05068543a25168d47a4526954ba64820200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 .....结果
这么多的零被追加。
可以指导我在这里丢失的内容。
解决方案在你的示例中，图像的宽度（以及字节数组大小的1/4）被设置为986，这将产生你观察到的行为 - 你实际上并不传递 986 * 4 字节的数据，但Bitmap确实有这么多。所以你会得到你实际复制到位图的第一个X字节，然后全部零。换句话说，看来你的问题是你的示例数据，而不是方法本身 - 这些工作很好。
I have a Hex string that's coming from postscript file.
<< /ImageType 1
/Width 986 /Height 1
/BitsPerComponent 8
/Decode [0 1 0 1 0 1]
/ImageMatrix [986 0 0 -1 0 1]
/DataSource <
803fe0503824160d0784426150b864361d0f8844625138a4562d178c466351b8e4763d1f904864523924964d27944a6552b964b65d2f984c665339a4d66d379c4e6753b9e4f67d3fa05068543a25168d47a4526954ba648202
> /LZWDecode filter >> image } def
Below are the methods that I am using. I have commented out the method for updating color.
public static void ProcessImageColourMapping()
{
string imageDataSource = "803fe0503824160d0784426150b864361d0f8844625138a4562d178c466351b8e4763d1f904864523924964d27944a6552b964b65d2f984c665339a4d66d379c4e6753b9e4f67d3fa05068543a25168d47a4526954ba648202";
string imageDataSourceUpdated = GetUpdatedImage(imageDataSource);
}
public static string GetUpdatedImage(string strImageDataSource)
{
string imageDataSourceUpdated = "";
byte[] imageBytes = StringToByteArray(strImageDataSource);
Bitmap bitmapImage = ByteArrayToBitmap(imageBytes);
//UpdateColour(bitmapImage);
byte[] imageBytesUpdated = BitmapToByteArray(bitmapImage);
imageDataSourceUpdated = ByteArrayToString(imageBytesUpdated);
return imageDataSourceUpdated;
}
public static byte[] StringToByteArray(String imageHexString)
{
int numberOfChars = imageHexString.Length / 2;
byte[] byteArray = new byte[numberOfChars];
using (var sr = new StringReader(imageHexString))
{
for (int i = 0; i < numberOfChars; i++)
byteArray[i] = Convert.ToByte(new string(new char[2] { (char)sr.Read(), (char)sr.Read() }), 16);
}
return byteArray;
}
public static Bitmap ByteArrayToBitmap(byte[] byteArray)
{
int width = 986; //width and height are taken from postscript file for testing a single hex string.
int height = 1;
Bitmap bitmapImage = new Bitmap(width, height, PixelFormat.Format32bppPArgb);
BitmapData bmpData = bitmapImage.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.ReadWrite, PixelFormat.Format32bppPArgb);
try
{
Marshal.Copy(byteArray, 0, bmpData.Scan0, byteArray.Length);
}
finally
{
bitmapImage.UnlockBits(bmpData);
}
return bitmapImage;
}
public static byte[] BitmapToByteArray(Bitmap bitmap)
{
BitmapData bmpdata = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, bitmap.PixelFormat);
int numbytes = bmpdata.Stride * bitmap.Height;
byte[] bytedata = new byte[numbytes];
try
{
Marshal.Copy(bmpdata.Scan0, bytedata, 0, numbytes);
}
finally
{
bitmap.UnlockBits(bmpdata);
}
return bytedata;
}
public static string ByteArrayToString(byte[] byteArray)
{
StringBuilder hex = new StringBuilder(byteArray.Length * 2);
foreach (byte b in byteArray)
{
hex.AppendFormat("{0:x2}", b);
}
return hex.ToString();
}
Issue:
In below code, I am not updating anything for incoming Hex string imageDataSource.
Converting it to byte[] - then to Bitmap - Back to byte[] - and finally back to Hex string.
So, imageDataSourceUpdated should have same value as imageDataSource.
However, when I finally check the value for imageDataSourceUpdated, it comes out as:
803fe0503824160d0784426150b864361d0f8844625138a4562d178c466351b8e4763d1f904864523924964d27944a6552b964b65d2f984c665339a4d66d379c4e6753b9e4f67d3fa05068543a25168d47a4526954ba64820200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.....
So many zeros being appended.
Can please guide what I am missing here.
解决方案 You are passing some input string, but the width of the image (and so 1/4 of the size of the byte array) is set to 986 in your sample, which would yield the behaviour you observe - you're not actually passing 986 * 4 bytes of data, but the Bitmap does have that many. So you'll get the first X bytes you actually copied to the bitmap, and then all zeros. In other words, it seems your issue is with your sample data, not with the methods themselves - those work just fine.
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