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Hex Dump back to .jpg (Java)

I had this question after viewing Conveting image in hex format to a jpeg file.
i tried to solve the problem listed above using java:

                       int content;
	   	       String NextLine = ""; 
	   	       Charset ansi = Charset.forName("Cp1252");
	   	       byte[] nextChar = new byte[1];

                        FileInputStream hexReader = new FileInputStream("./HEX/picture.hex");
	   	    	BufferedWriter pictureWriter = new BufferedWriter(new FileWriter("./Pictures/picture.jpg"));
	   	    	
	   	    	while((content = hexReader.read()) != -1){
	   	    		    NextLine += (char)content;
	   	    		    content = hexReader.read();
	   	    			NextLine += (char)content;
	   	    			
	   	    			nextChar[0] = (byte)((Character.digit(NextLine.charAt(0), 16) << 4) + Character.digit(NextLine.charAt(1), 16));
	   	    			NextLine = new String(nextChar, ansi );
					
	   	    			pictureWriter.append(NextLine);
	   	    			NextLine = "";
	   	    		
	   	    	}
	   	    	hexReader.close();
	   	    	pictureWriter.close();

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I get a picture file using this method but the picture is currupted and glichy.
I suspect: The problem is that the characters 0x81, 0x8D, 0x8F, 0x90 and 0x9D are not supported by the Cp1252 charset

here are the files:

original .jpg file
original_picture.hex.txt original hex dump

result (corrupted .jpg file)

Thanks for your help :)

SOLUTION

Martin Miller

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Erar nitox

ASKER

@Martin Miller i did compare the hex dump of the original file with the dump of the resulting/corrupted file.
They differ whenever 81, 8D, 8F, 90 or 9D occure in the original dump. In the currupted file these values are just filled with 3F (char: '?')

SOLUTION

CEHJ

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ASKER CERTIFIED SOLUTION

CEHJ

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Erar nitox

ASKER

@CEHJ thanks, i will try that later :) Thank you very much for the fast response.

CEHJ

:)
Probably better to keep String out of it

    public static void makePic(String hexFile, String jpgFile) {
        final char ZERO = '0';
        try {
            try (Reader in = new FileReader(hexFile)) {
                try (OutputStream out = new FileOutputStream(jpgFile)) {
                    int buf = -1;
                    int numRead = -1;
                    int val = 0;
                    while ((buf = in.read()) > -1) {
                        if (buf != ZERO) {
                            val = Character.digit(buf, 16) << 4;
                        }

                        val |= Character.digit(in.read(), 16);
                        out.write(val);
                        val = 0;
                    }
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

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