java写的图片叠加的小程序 可用于叠加水印 logo等

package com.test; import java.awt.Image; import java.awt.Toolkit; import java.awt.image.MemoryImageSource; import java.io.FileInputStream; import java.io.IOException; /** * 处理bmp后缀的图片 * @author 代码来自网上 * */ public class BMPLoader { // build an int from a byte array - convert little to big endian public static int constructInt(byte[] in, int offset) { int ret = ((int) in[offset + 3] & 0xff); ret = (ret << 8) | ((int) in[offset + 2] & 0xff); ret = (ret << 8) | ((int) in[offset + 1] & 0xff); ret = (ret << 8) | ((int) in[offset + 0] & 0xff); return (ret); } // build an int from a byte array - convert little to big endian // set high order bytes to 0xfff public static int constructInt3(byte[] in, int offset) { int ret = 0xff; ret = (ret << 8) | ((int) in[offset + 2] & 0xff); ret = (ret << 8) | ((int) in[offset + 1] & 0xff); ret = (ret << 8) | ((int) in[offset + 0] & 0xff); return (ret); } // build an int from a byte array - convert little to big endian public static long constructLong(byte[] in, int offset) { long ret = ((long) in[offset + 7] & 0xff); ret |= (ret << 8) | ((long) in[offset + 6] & 0xff); ret |= (ret << 8) | ((long) in[offset + 5] & 0xff); ret |= (ret << 8) | ((long) in[offset + 4] & 0xff); ret |= (ret << 8) | ((long) in[offset + 3] & 0xff); ret |= (ret << 8) | ((long) in[offset + 2] & 0xff); ret |= (ret << 8) | ((long) in[offset + 1] & 0xff); ret |= (ret << 8) | ((long) in[offset + 0] & 0xff); return (ret); } // build an double from a byte array - convert little to big endian public static double constructDouble(byte[] in, int offset) { long ret = constructLong(in, offset); return (Double.longBitsToDouble(ret)); } // build an short from a byte array - convert little to big endian public static short constructShort(byte[] in, int offset) { short ret = (short) ((short) in[offset + 1] & 0xff); ret = (short) ((ret << 8) | (short) ((short) in[offset + 0] & 0xff)); return (ret); } // internal class representing a bitmap header structure // with code to read it from a file static class BitmapHeader { public int nsize; public int nbisize; public int nwidth; public int nheight; public int nplanes; public int nbitcount; public int ncompression; public int nsizeimage; public int nxpm; public int nypm; public int nclrused; public int nclrimp; // read in the bitmap header public void read(FileInputStream fs) throws IOException { final int bflen = 14; // 14 byte BITMAPFILEHEADER byte bf[] = new byte[bflen]; fs.read(bf, 0, bflen); final int bilen = 40; // 40-byte BITMAPINFOHEADER byte bi[] = new byte[bilen]; fs.read(bi, 0, bilen); // Interperet data. nsize = constructInt(bf, 2); // System.out.println("File type is :"+(char)bf[0]+(char)bf[1]); // System.out.println("Size of file is :"+nsize); nbisize = constructInt(bi, 2); // System.out.println("Size of bitmapinfoheader is :"+nbisize); nwidth = constructInt(bi, 4); // System.out.println("Width is :"+nwidth); nheight = constructInt(bi, 8); // System.out.println("Height is :"+nheight); nplanes = constructShort(bi, 12); // (((int)bi[13]&0xff)<<8) | // (int)bi[12]&0xff; // System.out.println("Planes is :"+nplanes); nbitcount = constructShort(bi, 14); // (((int)bi[15]&0xff)<<8) | // (int)bi[14]&0xff; // System.out.println("BitCount is :"+nbitcount); // Look for non-zero values to indicate compression ncompression = constructInt(bi, 16); // System.out.println("Compression is :"+ncompression); nsizeimage = constructInt(bi, 20); // System.out.println("SizeImage is :"+nsizeimage); nxpm = constructInt(bi, 24); // System.out.println("X-Pixels per meter is :"+nxpm); nypm = constructInt(bi, 28); // System.out.println("Y-Pixels per meter is :"+nypm); nclrused = constructInt(bi, 32); // System.out.println("Colors used are :"+nclrused); nclrimp = constructInt(bi, 36); // System.out.println("Colors important are :"+nclrimp); } } public static Image read(FileInputStream fs) { try { BitmapHeader bh = new BitmapHeader(); bh.read(fs); if (bh.nbitcount == 24) return (readMap24(fs, bh)); if (bh.nbitcount == 32) return (readMap32(fs, bh)); if (bh.nbitcount == 8) return (readMap8(fs, bh)); fs.close(); } catch (IOException e) { // System.out.println("Caught exception in loadbitmap!"); } return (null); } /** * * readMap24 internal routine to read the bytes in a 24 bit bitmap * * * * Arguments: * * fs - file stream * * bh - header struct * * Returns: * * Image Object, be sure to check for (Image)null !!!! * * * */ protected static Image readMap32(FileInputStream fs, BitmapHeader bh) throws IOException { Image image; // No Palatte data for 24-bit format but scan lines are // padded out to even 4-byte boundaries. int xwidth = bh.nsizeimage / bh.nheight; int ndata[] = new int[bh.nheight * bh.nwidth]; byte brgb[] = new byte[bh.nwidth * 4 * bh.nheight]; fs.read(brgb, 0, bh.nwidth * 4 * bh.nheight); int nindex = 0; for (int j = 0; j < bh.nheight; j++) { for (int i = 0; i < bh.nwidth; i++) { ndata[bh.nwidth * (bh.nheight - j - 1) + i] = constructInt3( brgb, nindex); nindex += 4; } } image = Toolkit.getDefaultToolkit().createImage (new MemoryImageSource(bh.nwidth, bh.nheight, ndata, 0, bh.nwidth)); fs.close(); return (image); } /** * * readMap24 internal routine to read the bytes in a 24 bit bitmap * * * * Arguments: * * fs - file stream * * bh - header struct * * Returns: * * Image Object, be sure to check for (Image)null !!!! * * * */ protected static Image readMap24(FileInputStream fs, BitmapHeader bh) throws IOException { Image image; // No Palatte data for 24-bit format but scan lines are // padded out to even 4-byte boundaries. int npad = (bh.nsizeimage / bh.nheight) - bh.nwidth * 3; int ndata[] = new int[bh.nheight * bh.nwidth]; byte brgb[] = new byte[(bh.nwidth + npad) * 3 * bh.nheight]; fs.read(brgb, 0, (bh.nwidth + npad) * 3 * bh.nheight); int nindex = 0; for (int j = 0; j < bh.nheight; j++) { for (int i = 0; i < bh.nwidth; i++) { ndata[bh.nwidth * (bh.nheight - j - 1) + i] = constructInt3( brgb, nindex); nindex += 3; } nindex += npad; } image = Toolkit.getDefaultToolkit().createImage (new MemoryImageSource(bh.nwidth, bh.nheight, ndata, 0, bh.nwidth)); fs.close(); return (image); } /** * * readMap8 internal routine to read the bytes in a 8 bit bitmap * * * * Arguments: * * fs - file stream * * bh - header struct * * Returns: * * Image Object, be sure to check for (Image)null !!!! * * * */ protected static Image readMap8(FileInputStream fs, BitmapHeader bh) throws IOException { Image image; // Have to determine the number of colors, the clrsused // parameter is dominant if it is greater than zero. If // zero, calculate colors based on bitsperpixel. int nNumColors = 0; if (bh.nclrused > 0) { nNumColors = bh.nclrused; } else { nNumColors = (1 & 0xff) << bh.nbitcount; } // System.out.println("The number of Colors is"+nNumColors); // Some bitmaps do not have the sizeimage field calculated