{"id":73,"date":"2008-05-01T17:05:31","date_gmt":"2008-05-01T21:05:31","guid":{"rendered":"http:\/\/www.prglab.com\/blog\/p\/73"},"modified":"2009-04-20T15:50:49","modified_gmt":"2009-04-20T19:50:49","slug":"%e4%bd%bf%e7%94%a8java%e5%b0%86%e5%bd%a9%e8%89%b2%e5%9b%be%e7%89%87%e5%8f%98%e4%b8%ba1bit%e9%bb%91%e7%99%bd%e5%9b%be%e7%89%87","status":"publish","type":"post","link":"https:\/\/www.prglab.com\/blog\/p\/73","title":{"rendered":"\u4f7f\u7528JAVA\u5c06\u5f69\u8272\u56fe\u7247\u53d8\u4e3a1bit\u9ed1\u767d\u56fe\u7247"},"content":{"rendered":"

\u6700\u8fd1\u505a\u7684project\u9700\u8981\u6d89\u53ca\u5230\u5bf9\u626b\u63cf\u56fe\u7247\u7684\u6587\u5b57\u8bc6\u522b\uff0c\u9700\u8981\u5c06\u626b\u63cf\u5f97\u5230\u7684\u5f69\u8272\u56fe\u7247\u53d8\u4e3a1bit\u7684\u9ed1\u767d\u56fe\u7247\u3002<\/p>\n

\u641c\u7d22\u5230\u5f88\u591a\u89e3\u51b3\u65b9\u6848\uff0c\u57fa\u672c\u7684\u5f52\u7eb3\u4e3a\u4e24\u4e2a\u6b65\u9aa4\uff0c\u9996\u5148\u8981\u5c06\u5f69\u8272\u56fe\u7247\u53d8\u4e3a8bit\u7070\u5ea6\u56fe\u7247(grayscale image)\uff0c\u7136\u540e\u518d\u8fdb\u4e00\u6b65\u53d8\u4e3a1bit\u7684\u5355\u8272\u56fe\u7247(1bit monochrome)\u3002<\/p>\n

\u65b9\u6848\u4e00\uff1a\u4f7f\u7528ColorConvert\u548cDithering\u64cd\u4f5c<\/h3>\n

1\u3001\u4ee3\u7801<\/h4>\n

\u76ee\u524dJAVA\u6700\u65b0\u7684\u56fe\u7247\u5904\u7406\u5305\u5e94\u8be5\u662fJAI(Java Advanced Imaging)\uff0c\u5728JAI API\u7684FAQ\u9875\u9762<\/a>\u4e0a\uff0c\u627e\u5230\u4e86\u4e0b\u9762\u7684\u65b9\u6cd5\u6765\u5b8c\u6210\u8fd9\u4e24\u6b65\u5de5\u4f5c\uff1a<\/p>\n\n\n\n\n
\u5c06\u5f69\u8272\u56fe\u7247\u8f6c\u6362\u4e3a8bit\u7070\u5ea6\u56fe\u7247(\u4f7f\u7528ColorConvert\u989c\u8272\u8f6c\u6362\u64cd\u4f5c)<\/td>\n<\/tr>\n
[java]
\npublic RenderedImage convertTo8BitGray(RenderedImage colorImage){
\nParameterBlock pb = new ParameterBlock();
\npb.addSource(colorImage);
\nColorModel cm = new ComponentColorModel(
\nColorSpace.getInstance(ColorSpace.CS_GRAY),
\nnew int[]{8},
\nfalse,
\nfalse,
\nTransparency.OPAQUE,
\nDataBuffer.TYPE_BYTE);
\npb.add(cm);
\nRenderedImage grayImage = JAI.create(“ColorConvert”, pb);
\nreturn grayImage;
\n}[\/java]<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n
\u5c068bit\u7070\u5ea6\u56fe\u7247\u8f6c\u6362\u4e3a1bit\u9ed1\u767d\u56fe\u7247 (\u4f7f\u7528errordiffusion\u6216ordereddither\u64cd\u4f5c)<\/td>\n<\/tr>\n
[java]
\npublic RenderedImage applyDithering(RenderedImage grayImage, boolean isErrorDiffusion){
\n\/\/ Load the ParameterBlock for the dithering operation
\n\/\/ and set the operation name.
\nParameterBlock pb = new ParameterBlock();
\npb.addSource(grayImage);
\nString opName = null;
\nif(isErrorDiffusion) {
\nopName = “errordiffusion”;
\nLookupTableJAI lut = new LookupTableJAI(new byte[] {(byte)0x00, (byte)0xff});
\npb.add(lut);
\npb.add(KernelJAI.ERROR_FILTER_FLOYD_STEINBERG);
\n} else {
\nopName = “ordereddither”;
\nColorCube cube = ColorCube.createColorCube(DataBuffer.TYPE_BYTE,
\n0, new int[] {2}); \/\/\u5c1d\u8bd5\u6539\u53d82\u4e3a\u5176\u5b83\u503c\uff0c\u53ef\u4ee5\u5f97\u5230\u4e0d\u540c\u6548\u679c
\npb.add(cube);
\npb.add(KernelJAI.DITHER_MASK_441);
\n}
\n\/\/ Create a layout containing an IndexColorModel which maps
\n\/\/ zero to zero and unity to 255.
\nImageLayout layout = new ImageLayout();
\nbyte[] map = new byte[] {(byte)0x00, (byte)0xff};
\nColorModel cm = new IndexColorModel(1, 2, map, map, map);
\nlayout.setColorModel(cm);
\n\/\/ Create a hint containing the layout.
\nRenderingHints hints = new RenderingHints(JAI.KEY_IMAGE_LAYOUT, layout);
\n\/\/ Dither the image.
\nbwImage = JAI.create(opName, pb, hints);
\nreturn bwImage;
\n}
\n[\/java]<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

2\u3001\u95ee\u9898<\/h4>\n

\u8fd9\u6bb5sample code\u5728\u5f88\u591a\u5730\u65b9\u90fd\u88ab\u63d0\u5230\u8fc7\uff0c\u6211\u4e0d\u77e5\u9053\u522b\u4eba\u662f\u5426\u80fd\u591f\u8ba9\u5b83\u987a\u5229\u6267\u884c\uff0c\u4f46\u662f\u5728\u6211\u7684\u673a\u5668\u4e0a\u662f\u4e0d\u884c\u7684\u3002<\/p>\n

\u95ee\u9898\u4e3b\u8981\u51fa\u5728\u7b2c\u4e00\u4e2aconvertTo8BitGray()\u51fd\u6570\u91cc\u7684ColorConvert\u64cd\u4f5c\u4e0a\u3002\u5728\u6267\u884c\u5b8cColorConvert\u4e4b\u540e\uff0c\u56fe\u7247\u7684ColorModel\u7684numberOfComponents\u53d8\u4e3a1\u3002\u6211\u7684\u7406\u89e3\u662f\u56e0\u4e3a\u53d8\u4e3a\u7070\u5ea6\u56fe\u7247\uff0c\u53ea\u6709\u4e00\u4e2a\u8272\u4e86\u3002<\/p>\n

\u7136\u800c\u4e0d\u77e5\u4e3a\u4ec0\u4e48\uff0c\u56fe\u7247\u7684SampleModel\u7684numberOfBands\u5374\u4ecd\u7136\u4fdd\u6301\u4e863\uff0c\u8fd9\u5c31\u9020\u6210\u4e86SampleModel\u548cColorModel \u4e0d\u517c\u5bb9\uff0c\u6240\u4ee5\u7a0b\u5e8f\u603b\u662f\u629b\u51fajava.lang.IllegalArgumentException: The specified ColorModel is incompatible with the image SampleModel…<\/span>\u7684\u9519\u8bef\u3002<\/p>\n

<\/p>\n

\u65b9\u6848\u4e8c\uff1a\u4f7f\u7528\u91cd\u753b\u5230\u7070\u5ea6\u56fe\u7247\u4e0a\u7684\u65b9\u6cd5<\/h3>\n

\u540e\u6765\u6211\u5728Code Beach\u770b\u5230\u4e86\u8fd9\u7bc7\u6587\u7ae0<\/a>\uff0c\u8bd5\u7528\u4e86\u91cc\u9762\u7684\u7b2c\u4e8c\u4e2a\u65b9\u6cd5 — \u5c06\u5f69\u8272\u56fe\u7247\u753b\u5230\u4e00\u4e2a\u7070\u5ea6\u56fe\u7247\u4e0a\u7684\u65b9\u6cd5\uff0c\u7ec8\u4e8e\u53ef\u4ee5\u6210\u529f\u5c06\u5f69\u8272\u56fe\u7247\u8f6c\u5316\u4e3a8bit\u7684\u7070\u5ea6\u56fe\u7247\u3002\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n

[java]
\nBufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_BYTE_GRAY);
\nGraphics g = image.getGraphics();
\ng.drawImage(colorImage, 0, 0, null);
\ng.dispose();
\n[\/java]<\/p>\n

\u8f6c\u6362\u7684\u6548\u679c\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n
\u8f6c\u6362\u524d\uff1a\u5f69\u8272\u56fe\u7247
\n
\n\"rose.jpg\"<\/a><\/td>\n		\u8f6c\u6362\u540e\uff1a\u7070\u5ea6\u56fe\u7247
\n
\n\"rose_gray.jpg\"<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

<\/p>\n

\u4f7f\u7528Binarize\u5c068bit\u7070\u5ea6\u56fe\u7247\u8f6c\u6362\u4e3a1bit\u9ed1\u767d\u56fe\u7247<\/h3>\n

\u5c06\u5f69\u8272\u56fe\u7247\u8f6c\u6362\u4e3a\u7070\u5ea6\u56fe\u7247\u540e\uff0c\u4ecd\u7136\u53ef\u4ee5\u7528\u524d\u9762\u7a0b\u5e8f\u4f8b\u5b50\u4e2d\u7684applyDithering()\u65b9\u6cd5\u6765\u5c068bit\u7070\u5ea6\u56fe\u7247\u8fdb\u4e00\u6b65\u8f6c\u6362\u4e3a1bit\u9ed1\u767d\u56fe\u7247\uff0c\u5f97\u5230\u7684\u6548\u679c\u6bd4\u8f83\u8c61\u62a5\u7eb8\u4e0a\u7684\u9ed1\u767d\u56fe\u7247\uff0c\u4fdd\u7559\u4e86\u5f88\u591a\u7070\u5ea6\u7684\u5c42\u6b21\u3002
\n\u4e3a\u4e86\u80fd\u591f\u66f4\u8fdb\u4e00\u6b65\u5f97\u5230\u7248\u753b\u6548\u679c\u7684\u56fe\u7247\uff0c\u53ef\u4ee5\u4f7f\u7528Binarize\u64cd\u4f5c\u3002\u6539\u53d8Binarize\u64cd\u4f5c\u7684\u57df\u503c(threshold)\u4e5f\u53ef\u4ee5\u5f97\u5230\u4e0d\u540c\u6548\u679c\u3002
\n\u4ee3\u7801\uff1a<\/strong>
\n[java]
\n\/***
\n* Binarize image (convert image to 1 bit black and white)
\n* \u8f93\u5165\u56fe\u7247\u5fc5\u987b\u4e3a\u7070\u5ea6\u56fe\u7247\uff0c\u5426\u5219\u4f1a\u51fa\u9519\u3002
\n*\/
\npublic RenderedImage applyBinarize(RenderedImage grayImage) {
\n\/\/ Generate a histogram.
\nHistogram histogram =
\n(Histogram)JAI.create(“histogram”, grayImage).getProperty(“histogram”);
\n\/\/ Get a threshold equal to the median.
\ndouble[] threshold = histogram.getPTileThreshold(0.4); \/\/\u6539\u53d8\u57df\u503c\u53ef\u4ee5\u5f97\u5230\u4e0d\u540c\u6548\u679c
\n\/\/ Binarize the image.
\nRenderedImage bwImage =
\nJAI.create(“binarize”, grayImage, new Double(threshold[0]));
\nreturn bwImage;
\n}\/\/function applyBinarize
\n[\/java]<\/p>\n

\u6548\u679c\uff1a<\/strong><\/p>\n\n\n\n\n
\u4f7f\u7528Dithering\u7684\u6548\u679c<\/td>\n\u4f7f\u7528Binarizing\u7684\u6548\u679c<\/td>\n<\/tr>\n
\"rose_dithering.jpg\"<\/a><\/td>\n\"rose_bw.jpg\"<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

\u6700\u8fd1\u505a\u7684project\u9700\u8981\u6d89\u53ca\u5230\u5bf9\u626b\u63cf\u56fe\u7247\u7684\u6587\u5b57\u8bc6\u522b\uff0c\u9700\u8981\u5c06\u626b\u63cf\u5f97\u5230\u7684\u5f69\u8272\u56fe\u7247\u53d8\u4e3a1bit\u7684\u9ed1\u767d\u56fe\u7247\u3002 \u641c\u7d22\u5230\u5f88\u591a\u89e3\u51b3\u65b9\u6848\uff0c\u57fa\u672c\u7684\u5f52\u7eb3\u4e3a\u4e24\u4e2a\u6b65\u9aa4\uff0c\u9996\u5148\u8981\u5c06\u5f69\u8272\u56fe\u7247\u53d8\u4e3a8bit\u7070\u5ea6\u56fe\u7247(grayscale image)\uff0c\u7136\u540e\u518d\u8fdb\u4e00\u6b65\u53d8\u4e3a1bit\u7684\u5355\u8272\u56fe\u7247(1bit monochrome)\u3002 \u65b9\u6848\u4e00\uff1a\u4f7f\u7528ColorConvert\u548cDithering\u64cd\u4f5c 1\u3001\u4ee3\u7801 \u76ee\u524dJAVA\u6700\u65b0\u7684\u56fe\u7247\u5904\u7406\u5305\u5e94\u8be5\u662fJAI(Java Advanced Imaging)\uff0c\u5728JAI API\u7684FAQ\u9875\u9762\u4e0a\uff0c\u627e\u5230\u4e86\u4e0b\u9762\u7684\u65b9\u6cd5\u6765\u5b8c\u6210\u8fd9\u4e24\u6b65\u5de5\u4f5c\uff1a \u5c06\u5f69\u8272\u56fe\u7247\u8f6c\u6362\u4e3a8bit\u7070\u5ea6\u56fe\u7247(\u4f7f\u7528ColorConvert\u989c\u8272\u8f6c\u6362\u64cd\u4f5c) [java] public RenderedImage convertTo8BitGray(RenderedImage colorImage){ ParameterBlock pb = new ParameterBlock(); pb.addSource(colorImage); ColorModel cm = new ComponentColorModel( ColorSpace.getInstance(ColorSpace.CS_GRAY), new int[]{8}, false, false, Transparency.OPAQUE, DataBuffer.TYPE_BYTE); pb.add(cm); RenderedImage grayImage = JAI.create(“ColorConvert”, pb); return grayImage; }[\/java] \u5c068bit\u7070\u5ea6\u56fe\u7247\u8f6c\u6362\u4e3a1bit\u9ed1\u767d\u56fe\u7247 (\u4f7f\u7528errordiffusion\u6216ordereddither\u64cd\u4f5c) [java] public RenderedImage applyDithering(RenderedImage grayImage, boolean isErrorDiffusion){ \/\/ Load the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[9],"tags":[],"_links":{"self":[{"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/posts\/73"}],"collection":[{"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/comments?post=73"}],"version-history":[{"count":3,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/posts\/73\/revisions"}],"predecessor-version":[{"id":91,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/posts\/73\/revisions\/91"}],"wp:attachment":[{"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/media?parent=73"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/categories?post=73"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/tags?post=73"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}