Java 从数据转储中提取JPEG/PNG/GIF图像

我从磁盘获得二进制/十六进制数据转储。我的任务是从中提取图像。它是JPEG、PNG和GIF图像的混合转储

您可以在此处找到数据文件

图像的页眉和页脚

jpg:
 header: FF D8 FF E0 xx xx 4A 46 49 46 00, footer: FF D9
png:
 header: 89 50 4E 47 0D 0A 1A 0A, footer: 49 45 4E 44 AE 42 60 82
gif:
 header: 47 49 46 38 39 61, footer: 00 3B

在里面完好无损。如何使用Java提取图像？

我建议您：

将输入文件作为

文件inputstream

打开

扫描输入，直到找到其中一个标题

使用图像的正确文件扩展名，为输出文件打开一个新的

FileOutputStream

，并将内容复制到该文件，直到找到相应的页脚

关闭输出流

从第2步开始，直到到达流的末尾

关闭输入流。完成了

的源代码和字节码

这将对jpg有效

对于png

将

copyJpeg

功能替换为

private void copypng(InputStream in, OutputStream out) throws
    IOException
{
    boolean notFinished = true;
    long copiedBytes = 3;
    do
    {
        int v1 = in.read();
        if (v1 == 0x89) // marker
        {
            int v2 = in.read();
            if (v2 < 0) // end of file
            {
                out.write(0x82);
                copiedBytes++;
                notFinished = false;
            }
            else
            if (v2 == 0x49) // embedded png stream ended
            {
                // copy the end of stream marker
                out.write(0x49);
                out.write(0x45);
                out.write(0x4E);
                out.write(0x44);
                out.write(0xAE);
                out.write(0x42);
                out.write(0x60);
                out.write(0x82);
                copiedBytes += 2;
                notFinished = false;
            }
            else
            {
                // copy the two bytes, just a marker of the embedded png
                out.write(0x89);
                out.write(v2);
                copiedBytes += 2;
            }
        }
        else
        if (v1 == -1) // unexpected end of input file
        {
            notFinished = false;
        }
        else // just copy that value
        {
            out.write(v1);
            copiedBytes++;
        }
    }
    while (notFinished);
    totalBytes += copiedBytes;
    if (!quiet)
    {
        System.out.println(" (" + copiedBytes + " bytes)");
    }
    totalOutputFiles++;
    // close output stream
    try
    {
        out.close();
    }
    catch (IOException ioe)
    {
        // ignore error when closing output stream
    }
}

private void copygif(InputStream in, OutputStream out) throws
        IOException
    {
        boolean notFinished = true;
        long copiedBytes = 3;
        do
        {
            int v1 = in.read();
            if (v1 == 0x47) // marker
            {
                int v2 = in.read();
                if (v2 < 0) // end of file
                {
                    out.write(0x00);
                    copiedBytes++;
                    notFinished = false;
                }
                else
                if (v2 == 0x21) // embedded png stream ended
                {
                    // copy the end of stream marker
                    out.write(0x21);
                    out.write(0x00);
                    out.write(0x00);
                    out.write(0x3B);
                    out.write(0x00);
                    copiedBytes += 2;
                    notFinished = false;
                }
                else
                {
                    // copy the two bytes, just a marker of the embedded png
                    out.write(0x47);
                    out.write(v2);
                    copiedBytes += 2;
                }
            }
            else
            if (v1 == -1) // unexpected end of input file
            {
                notFinished = false;
            }
            else // just copy that value
            {
                out.write(v1);
                copiedBytes++;
            }
        }
        while (notFinished);
        totalBytes += copiedBytes;
        if (!quiet)
        {
            System.out.println(" (" + copiedBytes + " bytes)");
        }
        totalOutputFiles++;
        // close output stream
        try
        {
            out.close();
        }
        catch (IOException ioe)
        {
            // ignore error when closing output stream
        }
    }

对于gif， 将

copyJpeg

功能替换为

private void copypng(InputStream in, OutputStream out) throws
    IOException
{
    boolean notFinished = true;
    long copiedBytes = 3;
    do
    {
        int v1 = in.read();
        if (v1 == 0x89) // marker
        {
            int v2 = in.read();
            if (v2 < 0) // end of file
            {
                out.write(0x82);
                copiedBytes++;
                notFinished = false;
            }
            else
            if (v2 == 0x49) // embedded png stream ended
            {
                // copy the end of stream marker
                out.write(0x49);
                out.write(0x45);
                out.write(0x4E);
                out.write(0x44);
                out.write(0xAE);
                out.write(0x42);
                out.write(0x60);
                out.write(0x82);
                copiedBytes += 2;
                notFinished = false;
            }
            else
            {
                // copy the two bytes, just a marker of the embedded png
                out.write(0x89);
                out.write(v2);
                copiedBytes += 2;
            }
        }
        else
        if (v1 == -1) // unexpected end of input file
        {
            notFinished = false;
        }
        else // just copy that value
        {
            out.write(v1);
            copiedBytes++;
        }
    }
    while (notFinished);
    totalBytes += copiedBytes;
    if (!quiet)
    {
        System.out.println(" (" + copiedBytes + " bytes)");
    }
    totalOutputFiles++;
    // close output stream
    try
    {
        out.close();
    }
    catch (IOException ioe)
    {
        // ignore error when closing output stream
    }
}

private void copygif(InputStream in, OutputStream out) throws
        IOException
    {
        boolean notFinished = true;
        long copiedBytes = 3;
        do
        {
            int v1 = in.read();
            if (v1 == 0x47) // marker
            {
                int v2 = in.read();
                if (v2 < 0) // end of file
                {
                    out.write(0x00);
                    copiedBytes++;
                    notFinished = false;
                }
                else
                if (v2 == 0x21) // embedded png stream ended
                {
                    // copy the end of stream marker
                    out.write(0x21);
                    out.write(0x00);
                    out.write(0x00);
                    out.write(0x3B);
                    out.write(0x00);
                    copiedBytes += 2;
                    notFinished = false;
                }
                else
                {
                    // copy the two bytes, just a marker of the embedded png
                    out.write(0x47);
                    out.write(v2);
                    copiedBytes += 2;
                }
            }
            else
            if (v1 == -1) // unexpected end of input file
            {
                notFinished = false;
            }
            else // just copy that value
            {
                out.write(v1);
                copiedBytes++;
            }
        }
        while (notFinished);
        totalBytes += copiedBytes;
        if (!quiet)
        {
            System.out.println(" (" + copiedBytes + " bytes)");
        }
        totalOutputFiles++;
        // close output stream
        try
        {
            out.close();
        }
        catch (IOException ioe)
        {
            // ignore error when closing output stream
        }
    }

---

并更新

private void setDefaultArguments（）

中

outputSuffix

的值。是的，看起来查找标题将是一个非常好的开始。。。现在你可以搜索方法来实现这一点。我实际上不知道如何处理这些数据…搜索：java中的二进制搜索“不知道如何处理这些数据…”到底是什么问题？你的意思是你不知道什么是

byteArray

？或者你不能在字节内移动？或者，您不能执行

While

循环来搜索字节内的值？或者你甚至不能把你的十六进制转储文件带到Java中？你需要什么帮助？