![](/img/trans.png)
[英]How to convert 16 bit, tiff, Gray-Scale image into 32 bit ,tiff, Gray-Scale Image in java?
[英]how to convert a 8 bit gray scale bitmap to 4 bit scale in java?
我想读一个灰度图像文件,例如lena.bmp,然后降低java中的灰度级分辨率,我用PixelGrabber
来获取该图像的像素数据,如何将这个8位灰度位图转换为4位? 谢谢!
如果他们可以在这里帮助你,那不可能,但也许你可以看看JAI(Java高级成像) , Apache Commons Sanselan或Image4j 。
刚刚测试了Image4J库:
转换8位 - > 4位非常简单:
final File inFile = new File("test.bmp");
final File outFile = new File("test2.bmp");
BufferedImage inImage = ImageIO.read(inFile);
BufferedImage outImage = ConvertUtil.convert4(inImage); // Converts to 4 Bit
ImageIO.write(outImage, "bmp", outFile);
有关更多信息,请参见Image4J - ConvertUtil文档 。
这确实将位数减少到4:
public static void main(String[] args) throws Exception {
BufferedImage in = ImageIO.read(new File(args[0]));
int w = in.getWidth(), h = in.getHeight();
int[] bits = { 4 };
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY);
int dt = DataBuffer.TYPE_BYTE;
ColorModel cm = new ComponentColorModel
(cs, bits, false, false, Transparency.OPAQUE, dt);
WritableRaster wr = cm.createCompatibleWritableRaster(w, h);
BufferedImage out = new BufferedImage(cm, wr, false, null);
Graphics2D g = out.createGraphics();
g.drawImage(in, 0, 0, null);
g.dispose();
ImageIO.write(out, "png", new File(args[1]));
}
到目前为止,我尝试过的所有查看器应用程序的结果文件看起来都太暗了。 但是,如果你只对这些位感兴趣,那么在上面的转换对你来说,或许可以在wr
栅格上运行。
如果没有,那么也许你应该设置一个包含你想要的2 4个灰度级的IndexedColorModel
。 您可以简单地将索引乘以17以获得均匀间隔的强度,从0x0 * 17 = 0x00
到0xf * 17 = 0xff
。
public static void main(String[] args) throws Exception {
BufferedImage in = ImageIO.read(new File(args[0]));
int w = in.getWidth(), h = in.getHeight();
byte[] v = new byte[1 << 4];
for (int i = 0; i < v.length; ++i)
v[i] = (byte)(i*17);
ColorModel cm = new IndexColorModel(4, v.length, v, v, v);
WritableRaster wr = cm.createCompatibleWritableRaster(w, h);
BufferedImage out = new BufferedImage(cm, wr, false, null);
Graphics2D g = out.createGraphics();
g.drawImage(in, 0, 0, null);
g.dispose();
ImageIO.write(out, "png", new File(args[1]));
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.