java编解码png图片，java编解码png,该代码片段是用来提取pn
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java编解码png图片，java编解码png,该代码片段是用来提取pn
该代码片段是用来提取png图片中部分数据，不过不知道是解码有问题，还是编码有问题，还希望有高手能帮我瞧瞧，找出可能的问题。
读取png图片，截取部分数据
public static void getPngData(String path, Vector vMyPng) { // vFileNmae.add(path); DataInputStream dateInput = null; InputStream is = null; FileInputStream fr = null; byte[] pngHead = new byte[8];// 8B 8*8=64bit int length_Data;// 4B byte[] ChunkTypeCode_Data = new byte[4];// 4B char[] crc_Data = new char[2]; MyPng png = new MyPng(path); // is = new DataInputStream(this.getClass().getResourceAsStream(path)); is = new DataInputStream(IOControl.class.getResourceAsStream(path)); try { fr = new FileInputStream("res/" + path + ".png"); dateInput = new DataInputStream(fr); // 建FileReader对象，用来读取字符流 if (is == null) { System.out.println("1null!!"); return; } if (dateInput == null) { System.out.println("2null!!"); try { System.out.println(dateInput.available()); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return; } // dateInput. try { // png head System.out.println(dateInput.readInt()); System.out.println(dateInput.readInt()); System.out.println("======"); System.out.println(0x89504e47); System.out.println(0x0d0a1a0a); // other: Length ChunK_Type_Code Chunk_Data CRC while (true) { // dateInput.read(length_Data); length_Data = dateInput.readInt(); System.out.println("l=" + length_Data); // 4B ASC-11 1char2B for (int i = 0; i < ChunkTypeCode_Data.length; i++) { ChunkTypeCode_Data[i] = dateInput.readByte();// 32 } String str = new String(ChunkTypeCode_Data);// ASC-11 java // class编码采用UTF-8 System.out.println("TYPE: " + str); // "PLTE", "IDAT","IEND", "tRNS" if (RESERVED[0].contentEquals(str.trim())) { png.IHDR_length = length_Data; png.IHDR_ChunkTypeCode = new byte[4]; for (int i = 0; i < ChunkTypeCode_Data.length; i++) { png.IHDR_ChunkTypeCode[i] = ChunkTypeCode_Data[i]; } //png.IHDR_Data = new byte[png.IHDR_length]; png.width = dateInput.readInt(); png.height= dateInput.readInt(); png.bitDepth = dateInput.readByte(); png.colorType= dateInput.readByte(); png.compressionMethod= dateInput.readByte(); png.filterMethod = dateInput.readByte(); png.interlaceMethod= dateInput.readByte(); //dateInput.read(png.IHDR_Data); System.out.println(png.width); System.out.println(png.height); System.out.println(png.bitDepth); System.out.println(png.colorType); System.out.println(png.compressionMethod); System.out.println(png.filterMethod); System.out.println(png.interlaceMethod); // System.out.println(new String(png.IHDR_Data)); png.IHDR_crc = dateInput.readInt(); } else if (RESERVED[1].contentEquals(str.trim())) {// "PLTE" png.plte = true; png.PLTE_length = length_Data; png.PLTE_ChunkTypeCode = new byte[4]; for (int i = 0; i < ChunkTypeCode_Data.length; i++) { png.PLTE_ChunkTypeCode[i] = ChunkTypeCode_Data[i]; } png.PLTE_Data = new byte[png.PLTE_length]; dateInput.read(png.PLTE_Data); png.PLTE_crc = dateInput.readInt(); } else if (RESERVED[2].contentEquals(str.trim())) {// "IDAT" byte[] data = new byte[length_Data]; dateInput.read(data); png.setDate(length_Data, ChunkTypeCode_Data, data, dateInput.readInt()); } else if (RESERVED[3].contentEquals(str.trim())) {// "IEND" // png.IEND_length = length_Data; // System.out.println(Integer.toHexString(png.IEND_length)); // // png.IEND_ChunkTypeCode = new byte[4]; // for(int i=0;i<ChunkTypeCode_Data.length;i++){ // png.IEND_ChunkTypeCode[i] = ChunkTypeCode_Data[i]; // } // System.out.println(new String(png.IEND_ChunkTypeCode)); // png.IEND_Data = new byte[length_Data]; // dateInput.read(png.IEND_Data); // //System.out.println(new String(png.IEND_Data)); // //dateInput.read(PLTE_crc); // png.IEND_crc = dateInput.readInt(); // System.out.println(Integer.toHexString(png.IEND_crc)); vMyPng.add(png); return; } else if (RESERVED[4].contentEquals(str.trim())) {// "tRNS" png.tRNS = true; png.tRNS_length = length_Data; png.tRNS_ChunkTypeCode = new byte[4]; for (int i = 0; i < ChunkTypeCode_Data.length; i++) { png.tRNS_ChunkTypeCode[i] = ChunkTypeCode_Data[i]; } png.tRNS_Data = new byte[length_Data]; dateInput.read(png.tRNS_Data); png.tRNS_crc = dateInput.readInt(); } else { int counts = length_Data; System.out.println(counts); dateInput.skipBytes(counts + 4); } } // IEND } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } fr.close(); dateInput.close(); is.close(); } catch (FileNotFoundException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } }将截取的png数据，新建一个png
public static void putFile(Vector vMyPng) {//禁用read 跟 write DataOutputStream dateOutput = null; Enumeration e = vMyPng.elements(); while (e.hasMoreElements()) { try {// 20 20 xiao MyPng png = (MyPng) e.nextElement(); FileOutputStream fo = new FileOutputStream("d:\\" + png.strName + ".png"); dateOutput = new DataOutputStream(fo); //file dateOutput.writeInt(0x89504e47); dateOutput.writeInt(0x0d0a1a0a); // IHDR; int4 short2 short2 dateOutput.writeInt(13); dateOutput.writeInt(0x49484452); //dateOutput.writeInt(0x49484452); dateOutput.writeInt(png.width); dateOutput.writeInt(png.height); dateOutput.writeByte(png.bitDepth); dateOutput.writeByte(png.colorType); dateOutput.writeByte(png.compressionMethod); dateOutput.writeByte(png.filterMethod); dateOutput.writeByte(png.interlaceMethod); dateOutput.writeInt(png.IHDR_crc); // PLTE; dateOutput.writeBoolean(png.plte); if (png.plte) { dateOutput.writeInt(png.PLTE_length); System.out.println(png.PLTE_length); //dateOutput.write(png.PLTE_ChunkTypeCode); dateOutput.writeInt(0x504C5445); for(int i=0;i<png.PLTE_length;i++){ dateOutput.writeByte(png.PLTE_Data[i]); } dateOutput.writeInt(png.PLTE_crc); } // tRNS; dateOutput.writeBoolean(png.tRNS); if (png.tRNS) { dateOutput.writeInt(png.tRNS_length); //dateOutput.write(png.tRNS_ChunkTypeCode); dateOutput.writeInt(0x74524E53); //dateOutput.write(png.tRNS_Data); for(int i=0;i<png.tRNS_length;i++){ dateOutput.writeByte(png.tRNS_Data[i]); } dateOutput.writeInt(png.tRNS_crc); } // IDAT; dateOutput.writeInt(png.idatCounts); System.out.println("png.idatCounts: " + png.idatCounts); for (int i = 0; i < png.idatCounts; i++) { dateOutput.writeInt(png.IDAT_length[i]); System.out.println(png.IDAT_length[i]); dateOutput.writeInt(0x49444154); for(int j=0;j<png.IDAT_length[i];j++){ dateOutput.writeByte(png.IDAT_Data[i][j]); System.out.println(); } System.out.println(png.IDAT_Data[i].length+" i="+i); dateOutput.writeInt(png.IDAT_crc[i]); } // End System.out.println("end---"); dateOutput.writeInt(0x00000000);// Length dateOutput.writeInt(0x49454e44);// IEND dateOutput.writeInt(0xae426082);// CRC System.out.println(dateOutput.size()); dateOutput.flush(); fo.close(); System.out.println(dateOutput.size()); } catch (FileNotFoundException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } catch (IOException ioe) { ioe.printStackTrace(); } } try { dateOutput.flush(); dateOutput.close(); } catch (IOException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } }png对象
public class MyPng { public static final int head1 = 0x89504e47; public static final int head2 = 0x0d0a1a0a; private final int max = 10; boolean tRNS; boolean plte; int idatCounts; String strName; int IHDR_length; int PLTE_length; int tRNS_length; int[] IDAT_length = new int[max]; int IEND_length; byte[] IHDR_ChunkTypeCode; byte[] PLTE_ChunkTypeCode; byte[] tRNS_ChunkTypeCode; byte[][] IDAT_ChunkTypeCode = new byte[max][]; byte[] IEND_ChunkTypeCode; byte[] IHDR_Data; byte[] PLTE_Data; byte[] tRNS_Data; public byte[][] IDAT_Data = new byte[max][]; byte[] IEND_Data; int IHDR_crc; int PLTE_crc; int tRNS_crc; int[] IDAT_crc = new int[max]; int IEND_crc; public MyPng(String name){ this.strName = name; } public void setDate(int length,byte[] chunkTypeCode,byte[] idate_Data,int crc){ for(int i=0;i<max;i++){ if(IDAT_Data[i]==null){ IDAT_length[i] = length; IDAT_ChunkTypeCode[i] = new byte[4]; for(int a=0;a<chunkTypeCode.length;a++){ IDAT_ChunkTypeCode[i][a] = chunkTypeCode[a]; } System.out.println(" "+new String(IDAT_ChunkTypeCode[i])); IDAT_Data[i] = idate_Data; IDAT_crc[i] =crc; idatCounts++; break; } } }}
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