发国外的文章要求图片是tif，cmyk色彩空间的。

大小尺寸还有要求。

比如

网上大神多，找到了一段代码，感谢！

https://www.jianshu.com/p/ec2af4311f56

https://github.com/KevinZc007/image2Tif

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import javax.media.jai.JAI;
import javax.media.jai.PlanarImage;

//import com.sun.media.imageio.plugins.tiff.TIFFField;
import com.sun.media.imageio.plugins.tiff.TIFFTag;
import com.sun.media.jai.codec.FileSeekableStream;
import com.sun.media.jai.codec.TIFFEncodeParam;
import com.sun.media.jai.codecimpl.TIFFImageEncoder;
import com.sun.media.jai.codec.TIFFField;

public class Png2TifConvert {
/**
*
* 功能描述: 图片转tif格式
*
* @param: [fileAbsolutePath]
* @return: java.lang.String
* @auther: KevinZc  <- 就是他
* @date: 2018/9/8 22:14
*/
public static String image2Tif(String fileAbsolutePath){
OutputStream outputStream = null;
String filterFilePath = null;
String tifFilePath = null;
ImageOutputStream ios = null;
try {
// 解决位深度太小 start ====注意：8位深度的图片会出现文件损坏问题
File picture = new File(fileAbsolutePath);
BufferedImage img = ImageIO.read(picture);
int colorSpaceType = img.getColorModel().getColorSpace().getType();
System.out.print(colorSpaceType);
// 统一进行一次过滤 转换成24位深度
filterFilePath = fileAbsolutePath.substring(0, fileAbsolutePath.lastIndexOf("."))+".png";
tifFilePath = filterFilePath.substring(0, filterFilePath.lastIndexOf("."))+".tif";
ios = ImageIO.createImageOutputStream(new File(filterFilePath));
ImageIO.write(ImageIO.read(picture),"png", ios);
// 解决位深度太小 end
FileSeekableStream stream = new FileSeekableStream(filterFilePath);
PlanarImage in = JAI.create("stream", stream);
OutputStream os = null;
os = new FileOutputStream(tifFilePath);
// 设置dpi为300
TIFFEncodeParam param = new TIFFEncodeParam();
param.setCompression(TIFFEncodeParam.COMPRESSION_NONE);
TIFFField[] extras = new TIFFField[2];
extras[0] = new TIFFField(282, TIFFTag.TIFF_RATIONAL, 1, (Object) new long[][]{{(long) 300, 1}, {0, 0}});
// extras[0] = new TIFFField(282, TIFFTag.TIFF_RATIONAL, 1, (Object) new long[][]{{(long) dpi, 1}, {0, 0}});
extras[1] = new TIFFField(283, TIFFTag.TIFF_RATIONAL, 1, (Object) new long[][]{{(long) 300, 1}, {0, 0}});
param.setExtraFields(extras);

TIFFImageEncoder enc = new TIFFImageEncoder(os, param);
try {
enc.encode(in);
os.flush();
os.close();
stream.close();
} catch (Exception e) {
// logger.error("{}",e );
throw new RuntimeException(e);
}
return tifFilePath;
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (outputStream != null) {
outputStream.close();
}
if (ios != null) {
ios.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}

public static void main(String[] args) {
// TODO Auto-generated method stub
image2Tif("1.png");
System.out.print("done");
}

}

cmyk色彩空间，拿ps转比较好，不过没有ps，黑白图是否会影响?不清楚。。

不过java可以实现RGB转CMYK色彩空间。首先看下图片是否是CMYK空间，通常不是，输出是6 ，CMYK是9

BufferedImage img = ImageIO.read(picture);
int colorSpaceType = img.getColorModel().getColorSpace().getType();
System.out.print(colorSpaceType);

cmyk和rgb应该也存在一定的转换关系，但是转换完了是否还能在电脑里显示？因为电脑是rgb的色彩空间吧、

参考另外一个大神的方法,下面是转载的link，谢谢分享！

https://blog.csdn.net/ybn187/article/details/52185269

public static String readImage(String filename) throws IOException {
File file = new File(filename);
ImageInputStream input = ImageIO.createImageInputStream(file);
Iterator readers = ImageIO.getImageReaders(input);
if(readers == null || !readers.hasNext()) {
throw new RuntimeException("1 No ImageReaders found");
}
ImageReader reader = (ImageReader) readers.next();
reader.setInput(input);
String format = reader.getFormatName() ;
BufferedImage image;

if ( "JPEG".equalsIgnoreCase(format) ||"JPG".equalsIgnoreCase(format) ) {
try {
// 尝试读取图片 (包括颜色的转换).
image = reader.read(0); //RGB
} catch (IIOException e) {
// 读取Raster (没有颜色的转换).
Raster raster = reader.readRaster(0, null);//CMYK
image = createJPEG4(raster);
}
image.getGraphics().drawImage(image, 0, 0, null);
String dstfilename = filename.substring(0,filename.lastIndexOf("."))+"_rgb"+filename.substring(filename.lastIndexOf("."));
String newfilename = filename;
File newFile = new File(dstfilename);
FileOutputStream out = new FileOutputStream(newFile);
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(image);
out.flush();
out.close();
return dstfilename;
}
return null;
}

private static BufferedImage createJPEG4(Raster raster) {
int w = raster.getWidth();
int h = raster.getHeight();
byte[] rgb = new byte[w * h * 3];
//彩色空间转换
float[] Y = raster.getSamples(0, 0, w, h, 0, (float[]) null);
float[] Cb = raster.getSamples(0, 0, w, h, 1, (float[]) null);
float[] Cr = raster.getSamples(0, 0, w, h, 2, (float[]) null);
float[] K = raster.getSamples(0, 0, w, h, 3, (float[]) null);
for (int i = 0, imax = Y.length, base = 0; i < imax; i++, base += 3) {
float k = 220 - K[i], y = 255 - Y[i], cb = 255 - Cb[i],
cr = 255 - Cr[i];

double val = y + 1.402 * (cr - 128) - k;
val = (val - 128) * .65f + 128;
rgb[base] = val < 0.0 ? (byte) 0 : val > 255.0 ? (byte) 0xff
: (byte) (val + 0.5);

val = y - 0.34414 * (cb - 128) - 0.71414 * (cr - 128) - k;
val = (val - 128) * .65f + 128;
rgb[base + 1] = val < 0.0 ? (byte) 0 : val > 255.0 ? (byte) 0xff
: (byte) (val + 0.5);

val = y + 1.772 * (cb - 128) - k;
val = (val - 128) * .65f + 128;
rgb[base + 2] = val < 0.0 ? (byte) 0 : val > 255.0 ? (byte) 0xff
: (byte) (val + 0.5);
}
raster = Raster.createInterleavedRaster(new DataBufferByte(rgb, rgb.length), w, h, w * 3, 3, new int[]{0, 1, 2}, null);
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_sRGB);
ColorModel cm = new ComponentColorModel(cs, false, true, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
return new BufferedImage(cm, (WritableRaster) raster, true, null);
}

public static String TestImg(String src) {
File imgsrc = new File(src);
try {
ImageIO.read(imgsrc);
} catch (IOException e) {
// TODO Auto-generated catch block

String msg = e.getMessage();
System.out.println("msg:"+msg);
if (msg.indexOf("Unsupported Image Type") == 0) {
try {
return readImage(src);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
} else {
e.printStackTrace();
return null;
}
}
return src;

}