Java TGA 加载器

Question

我正在寻找用于 java 的小型免费 TGA 图像加载类或库。 理想情况下，结果是 BufferedImage。

是的，我已经用谷歌搜索过，但大多数结果都已过时，或者是相当大的库，其中包含许多我不需要的其他内容。我正在寻找只读取 TGA 图像的小而简单的东西。

谢谢!

Answer 1

我有未压缩的 targa 图像，因此必须调整示例代码。这是我的编辑，它应该支持未压缩的 targa 24 位 BGR 和 32 位 BGRA

// http://paulbourke.net/dataformats/tga/
// little endian multi-byte integers: "low-order byte,high-order byte"
//          00,04 -> 04,00 -> 1024
class TargaReader {
        public static BufferedImage getImage(String fileName) throws IOException {
                File f = new File(fileName);
                byte[] buf = new byte[(int)f.length()];
                BufferedInputStream bis = new BufferedInputStream(new FileInputStream(f));
                bis.read(buf);
                bis.close();
                return decode(buf);
        }

        private static int offset;

        private static int btoi(byte b) {
                int a = b;
                return (a<0?256+a:a);
        }

        private static int read(byte[] buf) {
                return btoi(buf[offset++]);
        }

        public static BufferedImage decode(byte[] buf) throws IOException {
                offset = 0;

                // Reading header bytes
                // buf[2]=image type code 0x02=uncompressed BGR or BGRA
                // buf[12]+[13]=width
                // buf[14]+[15]=height
                // buf[16]=image pixel size 0x20=32bit, 0x18=24bit 
                // buf{17]=Image Descriptor Byte=0x28 (00101000)=32bit/origin upperleft/non-interleaved
                for (int i=0;i<12;i++)
                        read(buf);
                int width = read(buf)+(read(buf)<<8);   // 00,04=1024
                int height = read(buf)+(read(buf)<<8);  // 40,02=576
                read(buf);
                read(buf);

                int n = width*height;
                int[] pixels = new int[n];
                int idx=0;

                if (buf[2]==0x02 && buf[16]==0x20) { // uncompressed BGRA
                    while(n>0) {
                        int b = read(buf);
                        int g = read(buf);
                        int r = read(buf);
                        int a = read(buf);
                        int v = (a<<24) | (r<<16) | (g<<8) | b;
                        pixels[idx++] = v;
                        n-=1;
                    }
                } else if (buf[2]==0x02 && buf[16]==0x18) {  // uncompressed BGR
                    while(n>0) {
                        int b = read(buf);
                        int g = read(buf);
                        int r = read(buf);
                        int a = 255; // opaque pixel
                        int v = (a<<24) | (r<<16) | (g<<8) | b;
                        pixels[idx++] = v;
                        n-=1;
                    }
                } else {
                    // RLE compressed
                    while (n>0) {
                        int nb = read(buf); // num of pixels
                        if ((nb&0x80)==0) { // 0x80=dec 128, bits 10000000
                            for (int i=0;i<=nb;i++) {
                                int b = read(buf);
                                int g = read(buf);
                                int r = read(buf);
                                pixels[idx++] = 0xff000000 | (r<<16) | (g<<8) | b;
                            }
                        } else {
                            nb &= 0x7f;
                            int b = read(buf);
                            int g = read(buf);
                            int r = read(buf);
                            int v = 0xff000000 | (r<<16) | (g<<8) | b;
                            for (int i=0;i<=nb;i++)
                                pixels[idx++] = v;
                        }
                        n-=nb+1;
                    }
                }

                BufferedImage bimg = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
                bimg.setRGB(0, 0, width,height, pixels, 0,width);
                return bimg;
        }
}