BIFF8 비트 맵 기록을 만들기위한 java.awt.image.BufferedImage 사용은 많은 시간을 소요 - 더 좋은 방법이 있습니까?

기타 2022-04-22 11:44:29 독서 시간: 0
악셀 리히터 :

나는이 만드는 오전 그래서 HSSFSheet사용하여 배경 비트 맵 세트를 가지고 apache poi와 자신의 낮은 수준의 코드를. https://www.openoffice.org/sc/excelfileformat.pdf는 에 대한 선언 Record BITMAP, BIFF8:

화소 데이터 (맨 윗줄에 하단 행에서 비트 맵의 ​​가로 라인 어레이, 아래 참조)

...

각 라인에서 모든 픽셀은 왼쪽에서 오른쪽으로 기록됩니다. 화소의 색의 적색, 녹색 및 청색 성분의 순서로 각 픽셀은 3 바이트 어레이로 저장된다. 각 라인의 크기는 마지막 픽셀 이후에 0 바이트를 삽입하여도 4의 배수에 정렬된다.

완전한 선언을위한 PDF의 그림을 참조하십시오 : 여기에 이미지 설명을 입력

이 내 접근 방식을 이행를 들어 사용 java.awt.image.BufferedImage을 갖는 형태를 BufferedImage.TYPE_3BYTE_BGR. 모든로부터 RGB 바이트 점점 그 폭 (X 방향)으로도 4의 배수에 충전 (아래쪽 상단 라인 선)에서 올바른 순서로 BufferedImage의 래스터.

코드를 참조하십시오 :

import java.io.FileOutputStream;
import java.io.FileInputStream;

import org.apache.poi.hssf.usermodel.*;

import org.apache.poi.hssf.record.RecordBase;
import org.apache.poi.hssf.record.StandardRecord;
import org.apache.poi.hssf.model.InternalSheet;
import org.apache.poi.util.LittleEndianOutput;

import java.lang.reflect.Field;

import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;

import java.awt.image.BufferedImage;
import java.awt.Graphics2D;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;

import javax.imageio.ImageIO;

public class CreateExcelHSSFSheetBackgroundBitmap {

 static List<Byte> getBackgroundBitmapData(String filePath) throws Exception {

  //see https://www.openoffice.org/sc/excelfileformat.pdf - BITMAP

  List<Byte> data = new ArrayList<Byte>();

  // get file byte data in type BufferedImage.TYPE_3BYTE_BGR
  BufferedImage in = ImageIO.read(new FileInputStream(filePath));
  BufferedImage image = new BufferedImage(in.getWidth(), in.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
  Graphics2D graphics = image.createGraphics();
  graphics.drawImage(in, null, 0, 0);
  graphics.dispose();

  short width = (short)image.getWidth();
  short height = (short)image.getHeight();

  // each pixel has 3 bytes but the width bytes must be filled up to multiple of 4
  int widthBytesMultOf4 = (int)((width * 3 + 3) / 4 * 4);

// --- this part takes much time but I have not found any better possibility

  // put the bytes R G B into the data; lines of the bitmap must be from bottom line to top line
  int bytes = 0;
  for (short y = (short)(height - 1); y >= 0; y--) {
   for (short x = 0; x < width; x++) {
    int r = image.getData().getSample(x, y, 2);
    data.add(Byte.valueOf((byte)r));
    bytes++;
    int g = image.getData().getSample(x, y, 1);
    data.add(Byte.valueOf((byte)g));
    bytes++;
    int b = image.getData().getSample(x, y, 0);
    data.add(Byte.valueOf((byte)b));
    bytes++;
   } 
   // fill up x with 0 bytes up to multiple of 4
   for (int x = width * 3; x < widthBytesMultOf4; x++) {
    data.add(Byte.valueOf((byte)0));
    bytes++;
   }
  }

// ---

  // size  12 bytes (additional headers, see below) + picture bytes
  int size = 12 + bytes;

  // get size int as LITTLE_ENDIAN bytes
  ByteBuffer bSize = ByteBuffer.allocate(4);
  bSize.order(ByteOrder.LITTLE_ENDIAN);
  bSize.putInt(size);

  // get width short as LITTLE_ENDIAN bytes
  ByteBuffer bWidth = ByteBuffer.allocate(2);
  bWidth.order(ByteOrder.LITTLE_ENDIAN);
  bWidth.putShort(width);

  // get height short as LITTLE_ENDIAN bytes
  ByteBuffer bHeight = ByteBuffer.allocate(2);
  bHeight.order(ByteOrder.LITTLE_ENDIAN);
  bHeight.putShort(height);

  // put the record headers into the data
  Byte[] dataPart = new Byte[] { 0x09, 0x00, 0x01, 0x00, 
     bSize.array()[0], bSize.array()[1], bSize.array()[2], bSize.array()[3], // size
     //now 12 bytes follow
     0x0C, 0x00, 0x00, 0x00, 
     bWidth.array()[0], bWidth.array()[1], // width
     bHeight.array()[0], bHeight.array()[1], // height
     0x01, 0x00, 0x18, 0x00
   }; 

  data.addAll(0, Arrays.asList(dataPart));

  return data;
 }

 public static void main(String[] args) throws Exception {

  HSSFWorkbook workbook = new HSSFWorkbook();
  HSSFSheet sheet = workbook.createSheet("Sheet1");
  sheet = workbook.createSheet("Sheet2"); // this sheet gets the background image set

  // we need the binary records of the sheet
  // get InternalSheet
  Field _sheet = HSSFSheet.class.getDeclaredField("_sheet");
  _sheet.setAccessible(true); 
  InternalSheet internalsheet = (InternalSheet)_sheet.get(sheet); 

  // get List of RecordBase
  Field _records = InternalSheet.class.getDeclaredField("_records");
  _records.setAccessible(true);
  @SuppressWarnings("unchecked") 
  List<RecordBase> records = (List<RecordBase>)_records.get(internalsheet);

  // get bytes of the image file
  List<Byte> data = getBackgroundBitmapData("dummyText.png"); //PNG must not have transparency

  // do creating BitmapRecord and ContinueRecords from the data in parts of 8220 bytes
  BitmapRecord bitmapRecord = null;
  List<ContinueRecord> continueRecords = new ArrayList<ContinueRecord>();
  int bytes = 0;
  if (data.size() > 8220) {
   bitmapRecord = new BitmapRecord(data.subList(0, 8220));
   bytes = 8220;
   while (bytes < data.size()) {
    if ((bytes + 8220) < data.size()) {
     continueRecords.add(new ContinueRecord(data.subList(bytes, bytes + 8220)));
     bytes += 8220;
    } else {
     continueRecords.add(new ContinueRecord(data.subList(bytes, data.size())));
     break;
    }
   }
  } else {
   bitmapRecord = new BitmapRecord(data);
  }

  // add the records after PageSettingsBlock
  int i = 0;
  for (RecordBase r : records) {
   if (r instanceof org.apache.poi.hssf.record.aggregates.PageSettingsBlock) {
    break;
   }
   i++;
  }
  records.add(++i, bitmapRecord);
  for (ContinueRecord continueRecord : continueRecords) {
   records.add(++i, continueRecord);  
  }

  // debug output
  for (RecordBase r : internalsheet.getRecords()) {
   System.out.println(r);
  }

  // write out workbook
  workbook.write(new FileOutputStream("CreateExcelHSSFSheetBackgroundBitmap.xls"));
  workbook.close();

 }

 static class BitmapRecord extends StandardRecord {

  //see https://www.openoffice.org/sc/excelfileformat.pdf - BITMAP

  List<Byte> data = new ArrayList<Byte>();

  BitmapRecord(List<Byte> data) {
   this.data = data;
  }

  public int getDataSize() { 
   return data.size(); 
  }

  public short getSid() {
   return (short)0x00E9;
  }

  public void serialize(LittleEndianOutput out) {
   for (Byte b : data) {
    out.writeByte(b);
   }
  }
 }

 static class ContinueRecord extends StandardRecord {

  //see https://www.openoffice.org/sc/excelfileformat.pdf - CONTINUE

  List<Byte> data = new ArrayList<Byte>();

  ContinueRecord(List<Byte> data) {
   this.data = data;
  }

  public int getDataSize() { 
   return data.size(); 
  }

  public short getSid() {
   return (short)0x003C;
  }

  public void serialize(LittleEndianOutput out) {
   for (Byte b : data) {
    out.writeByte(b);
   }
  }
 }

}

코드 작동하지만 사이의 부분 

// --- this part takes much time but I have not found any better possibility

과

// ---

(3) 위의 이상한 형식에 따라 그들을 얻기를 위해 가지고해야 할 각 개의 픽셀의 RGB 바이트 이후 많은 시간이 걸립니다.

합니까 누구는 더 나은 방법 알고? 내가 생각하는 그것의 다른 용도가 이미 있기 때문에 어쩌면 위의 이상한 형식이 이상으로하지 않습니다?

haraldK :

여기에 나를 위해 작동하고, 매우 빠른 코드의 수정 된 버전입니다.

  1. 내가 사용하지 않는거야 byte[](그리고 ByteArrayOutputStream더 이상, 모든 약을) List<Byte>.
  2. As we already have a BufferedImage of TYPE_3BYTE_BGR, we can use that almost directly as the BMP output. We just need to a) prepend a valid BMP header and b) write bottom-up, c) pad each scanline (row) to a 32 bit boundary and d) switch BGR -> RGB order.
  3. I'm using the Raster to copy (padded) rows of data into the output, as copying larger chunks is faster than copying single bytes.

As already noted in the comments, the structure is a standard BMP with BITMAPCOREHEADER (and no file header). Unfortunately, the ImageIO BMPImageWriter always write the file header and uses the BITMAPINFOHEADER which is 40 bytes. You could probably get around these things, and use the standard writer, by massaging the data a little (hint: the file header contains an offset to the pixel data at offset 10), but as the core BMP format is trivial to implement, it might be just as easy to do as below.

While the documentation certainly implies that using other formats like PNG and JPEG directly, I haven't managed to do this properly.

There's probably still room for improvement if you like, to avoid some byte array copying (ie. use offset/length and pass the entire data array to the Bitmap/ContinueRecords instead of Arrays.copyOfRange()).

Code:

import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.awt.image.Raster;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.lang.reflect.Field;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import javax.imageio.ImageIO;

import org.apache.poi.hssf.model.InternalSheet;
import org.apache.poi.hssf.record.RecordBase;
import org.apache.poi.hssf.record.StandardRecord;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.util.LittleEndianOutput;

public class CreateExcelHSSFSheetBackgroundBitmap {

    static byte[] getBackgroundBitmapData(String filePath) throws Exception {

        //see https://www.openoffice.org/sc/excelfileformat.pdf - BITMAP

        // get file byte data in type BufferedImage.TYPE_3BYTE_BGR
        BufferedImage in = ImageIO.read(new FileInputStream(filePath));
        BufferedImage image = new BufferedImage(in.getWidth(), in.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
        Graphics2D graphics = image.createGraphics();
        graphics.drawImage(in, null, 0, 0);
        graphics.dispose();

        // calculate row size (c)
        int rowSize = ((24 * image.getWidth() + 31) / 32) * 4;

        ByteArrayOutputStream output = new ByteArrayOutputStream(image.getHeight() * rowSize * 3 + 1024);

        // put the record headers into the data
        ByteBuffer header = ByteBuffer.allocate(8 + 12);
        header.order(ByteOrder.LITTLE_ENDIAN);

        // Undocumented XLS stuff
        header.putShort((short) 0x09);
        header.putShort((short) 0x01);
        header.putInt(image.getHeight() * rowSize + 12); // Size of image stream

        // BITMAPCOREHEADER (a)
        header.putInt(12);

        header.putShort((short) image.getWidth());
        header.putShort((short) image.getHeight()); // Use -height if writing top-down

        header.putShort((short) 1); // planes, always 1
        header.putShort((short) 24); // bitcount

        output.write(header.array());

        // Output rows bottom-up (b)
        Raster raster = image.getRaster()
                             .createChild(0, 0, image.getWidth(), image.getHeight(), 0, 0, new int[]{2, 1, 0}); // Reverse BGR -> RGB (d)
        byte[] row = new byte[rowSize]; // padded (c)

        for (int i = image.getHeight() - 1; i >= 0; i--) {
            row = (byte[]) raster.getDataElements(0, i, image.getWidth(), 1, row);
            output.write(row);
        }

        return output.toByteArray();
    }

    public static void main(String[] args) throws Exception {
        HSSFWorkbook workbook = new HSSFWorkbook();
        HSSFSheet sheet = workbook.createSheet("Sheet2"); // this sheet gets the background image set

        // we need the binary records of the sheet
        // get InternalSheet
        Field _sheet = HSSFSheet.class.getDeclaredField("_sheet");
        _sheet.setAccessible(true);
        InternalSheet internalsheet = (InternalSheet)_sheet.get(sheet);

        // get List of RecordBase
        Field _records = InternalSheet.class.getDeclaredField("_records");
        _records.setAccessible(true);
        @SuppressWarnings("unchecked")
        List<RecordBase> records = (List<RecordBase>)_records.get(internalsheet);

        // get bytes of the image file
        byte[] data = getBackgroundBitmapData("dummy.png"); //PNG must not have transparency

        // do creating BitmapRecord and ContinueRecords from the data in parts of 8220 bytes
        BitmapRecord bitmapRecord;
        List<ContinueRecord> continueRecords = new ArrayList<>();
        int bytes;

        if (data.length > 8220) {
            bitmapRecord = new BitmapRecord(Arrays.copyOfRange(data, 0, 8220));
            bytes = 8220;
            while (bytes < data.length) {
                if ((bytes + 8220) < data.length) {
                    continueRecords.add(new ContinueRecord(Arrays.copyOfRange(data, bytes, bytes + 8220)));
                    bytes += 8220;
                } else {
                    continueRecords.add(new ContinueRecord(Arrays.copyOfRange(data, bytes, data.length)));
                    break;
                }
            }
        } else {
            bitmapRecord = new BitmapRecord(data);
        }

        // add the records after PageSettingsBlock
        int i = 0;
        for (RecordBase r : records) {
            if (r instanceof org.apache.poi.hssf.record.aggregates.PageSettingsBlock) {
                break;
            }
            i++;
        }
        records.add(++i, bitmapRecord);
        for (ContinueRecord continueRecord : continueRecords) {
            records.add(++i, continueRecord);
        }

        // debug output
        for (RecordBase r : internalsheet.getRecords()) {
            System.out.println(r);
        }

        // write out workbook
        workbook.write(new FileOutputStream("backgroundImage.xls"));
        workbook.close();

    }

    static class BitmapRecord extends StandardRecord {

        //see https://www.openoffice.org/sc/excelfileformat.pdf - BITMAP

        byte[] data;

        BitmapRecord(byte[] data) {
            this.data = data;
        }

        public int getDataSize() {
            return data.length;
        }

        public short getSid() {
            return (short)0x00E9;
        }

        public void serialize(LittleEndianOutput out) {
            out.write(data);
        }
    }

    static class ContinueRecord extends StandardRecord {

        //see https://www.openoffice.org/sc/excelfileformat.pdf - CONTINUE

        byte[] data;

        ContinueRecord(byte[] data) {
            this.data = data;
        }

        public int getDataSize() {
            return data.length;
        }

        public short getSid() {
            return (short)0x003C;
        }

        public void serialize(LittleEndianOutput out) {
            out.write(data);
        }
    }
}

추천

출처http://43.154.161.224:23101/article/api/json?id=192818&siteId=1
추천
행
.netcoreapi 컨테이너와 컨테이너의 MySQL을 고정 표시기-구성
com.google.firebase.database.DatabaseException는 : 롱 타입 java.lang.String의 값을 변환하는 데 실패
국내 휴대전화 왕이 미국 통신사 시장 1위를 차지했지만 국내 휴대전화 4위는 아니다.
트랜잭션 격리 수준의 네 가지
오늘 chatgpt 시도
부하 분산
【FFMpeg】源码编译
우분투 sudo를 무료로 접착
자바 8 스트림 API - 어떤 상태 중간 동작을 보증 새로운 소스 수집합니까?
CF161BDiscounts
아카이브
기타
2020-04-08(1460)
2020-04-07(1517)
2020-04-06(1499)
2020-04-05(1440)
2020-04-04(1629)
2020-04-03(1644)
2020-04-02(1572)
2020-04-01(1665)
2020-03-31(1639)
2020-03-30(1334)

코드 세계

© 2018 codetd.com