javax.imageio.IIOException: Unsupported Image Type异常详解

一时失言乱红尘 2023-10-11 11:48 31阅读 0赞

# 声明： #

此文章的详解其实是个人遇到问题的解决方案，具体详细描述还要看各大佬的文章，一般都是英文的论坛大佬描述的比较好。解决方案也是借鉴大佬文章实现的

# 1、异常解释 #

javax.imageio.IIOException: Unsupported Image Type异常一般情况是由于图片颜色模式是CMYK导致的，因为其内部读取文件的类JPEGImageReader只能读取RGB color model

一般经过ps的图片自动保存曾jpeg格式颜色空间都会改变成CMYK，如果强行转换颜色空间会导致图片失色

gift的图色彩模式是CMYK模式（注意，这是给印刷机用的）在java.awt包下的Image类只能使用RGB模式，修改模式之后打水印会造成失色问题

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FsaWNlX3FpeGlu_size_16_color_FFFFFF_t_70][]  
失色图片效果：

如果是人脸的话，失色效果会更加让人不可接受，例如面无血色，嘴唇苍白～

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FsaWNlX3FpeGlu_size_16_color_FFFFFF_t_70 1][]

# 2、解决思路 #

水印图片不允许失色的情况所以要解决这个问题的主要思路就是

*  1如何使用CMYK颜色模式的图片
 *   
    
    2如果将CMYK颜色模式改成RGB并且不失色

### 我们先来看第一种，如何使用CMYK颜色模式的图片 ###

ImageIO类创建Image对象的时候调用 getImageTypesOnThread方法判断图片颜色类型

switch (colorSpaceCode) {
            case JPEG.JCS_GRAYSCALE:
                list.add(raw);
                list.add(getImageType(JPEG.JCS_RGB));
                break;
            case JPEG.JCS_RGB:
                list.add(raw);
                list.add(getImageType(JPEG.JCS_GRAYSCALE));
                list.add(getImageType(JPEG.JCS_YCC));
                break;
            case JPEG.JCS_RGBA:
                list.add(raw);
                break;
            case JPEG.JCS_YCC:
                if (raw != null) {  // Might be null if PYCC.pf not installed
                    list.add(raw);
                    list.add(getImageType(JPEG.JCS_RGB));
                }
                break;
            case JPEG.JCS_YCCA:
                if (raw != null) {  // Might be null if PYCC.pf not installed
                    list.add(raw);
                }
                break;
            case JPEG.JCS_YCbCr:
                // As there is no YCbCr ColorSpace, we can't support
                // the raw type.
    
                // due to 4705399, use RGB as default in order to avoid
                // slowing down of drawing operations with result image.
                list.add(getImageType(JPEG.JCS_RGB));
    
                if (iccCS != null) {
                    list.add(new ImageTypeProducer() {
                        protected ImageTypeSpecifier produce() {
                            return ImageTypeSpecifier.createInterleaved
                             (iccCS,
                              JPEG.bOffsRGB,  // Assume it's for RGB
                              DataBuffer.TYPE_BYTE,
                              false,
                              false);
                        }
                    });
    
                }
    
                list.add(getImageType(JPEG.JCS_GRAYSCALE));
                list.add(getImageType(JPEG.JCS_YCC));
                break;
            case JPEG.JCS_YCbCrA:  // Default is to convert to RGBA
                // As there is no YCbCr ColorSpace, we can't support
                // the raw type.
                list.add(getImageType(JPEG.JCS_RGBA));
                break;
            }

自动读取文件colorSpaceCode为9（抱歉这里真的没看懂什么时候赋值9的，可能除非改源码）code为9在这个switch中找不到对应类型抛出javax.imageio.IIOException: Unsupported Image Type异常

那么我们来看看JPEF类下有没有code为9的

源码片段：很明显，不知道什么原因，code为8和9的被注释掉无法使用

// IJG Color codes.
        public static final int JCS_UNKNOWN = 0;       // error/unspecified
        public static final int JCS_GRAYSCALE = 1;     // monochrome
        public static final int JCS_RGB = 2;           // red/green/blue
        public static final int JCS_YCbCr = 3;         // Y/Cb/Cr (also known as YUV)
        public static final int JCS_CMYK = 4;          // C/M/Y/K
        public static final int JCS_YCC = 5;           // PhotoYCC
        public static final int JCS_RGBA = 6;          // RGB-Alpha
        public static final int JCS_YCbCrA = 7;        // Y/Cb/Cr/Alpha
        // 8 and 9 were old "Legacy" codes which the old code never identified
        // on reading anyway.  Support for writing them is being dropped, too.
        public static final int JCS_YCCA = 10;         // PhotoYCC-Alpha
        public static final int JCS_YCCK = 11;         // Y/Cb/Cr/K
    
        public static final int NUM_JCS_CODES = JCS_YCCK+1;

ok到此为止，如果没有修改源码的能力，那么我去看一下第二步是否可以走得通

### 2、如果将CMYK颜色模式改成RGB并且不失色 ###

此处解决方法在我另一个文章，查看另一个文章即可看到解决方法的代码，

点击查看：[JAVA给照片添加平铺水印并解决javax.imageio.IIOException: Unsupported Image Type异常][JAVA_javax.imageio.IIOException_ Unsupported Image Type]

主要是用其他两个包的功能将转码缺失精度改成严格对应。

结局，感谢观看～

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FsaWNlX3FpeGlu_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20190923111024248.jpg?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FsaWNlX3FpeGlu,size_16,color_FFFFFF,t_70
[JAVA_javax.imageio.IIOException_ Unsupported Image Type]: https://blog.csdn.net/Alice_qixin/article/details/101196969