拉普拉斯銳化算法是讀取目標像素上下左右四個像素值，將上下左右四個像素值分別減去目標像素值，再將結果之和加上目標像素值作為目標像素最后的值，也就是說當目標像素與周圍像素差值較大，那么計算后會進一步拉大差值，突出圖像上物體邊緣部分，達到銳化效果。

一般jgp或者png格式圖像采用Java ImageIO直接讀取所有像素后進行拉普拉斯銳化即可，為了更方便讀取tif格式影像則需要引入gdal。使用gdal讀取tif影像基本信息，獲取影像寬、高、通道數。一般彩色影像包含RGB三個通道或者還有一個表示透明度的阿爾法通道。RGB通道一般對應tif圖像1、2、3通道，阿爾法通道一般為第4通道。

讀取影像基本信息：

gdal.AllRegister(); Dataset srcDataset = gdal.Open(srcImage.toString(), gdalconstConstants.GA_ReadOnly); int width = srcDataset.getRasterXSize(); int height = srcDataset.getRasterYSize(); Driver driver = srcDataset.GetDriver(); int count = srcDataset.GetRasterCount();

對tif影像進行拉普拉斯銳化，首先讀取影像信息后轉為BufferdImage，使用處理BufferdImage的拉普拉斯算法進行處理，之后再將BufferdImage轉為tif圖像。處理過程需要考慮到BufferdImage最大支持的圖像寬和高為26663，而tif格式正射影像沒有這一限制，那么處理過程需要考慮tif影像寬高是否超限，可以設定當tif影像寬或高超過26000像素就對影像進行拆分處理，如果沒有超限則直接讀取tif影像并轉換為BufferdImage。

具體實現：

if (count <= 3) {Dataset destDataset = driver.Create(destImage.toString(), width, height, count);destDataset.SetMetadata(srcDataset.GetMetadata_Dict()); Band srcBandR = srcDataset.GetRasterBand(1);Band srcBandG = srcDataset.GetRasterBand(2);Band srcBandB = srcDataset.GetRasterBand(3);Band destBandR = destDataset.GetRasterBand(1);Band destBandG = destDataset.GetRasterBand(2);Band destBandB = destDataset.GetRasterBand(3);int xIndex = (int)(width / 26000);int yIndex = (int)(height / 26000);int innerWidth = width / (xIndex + 1);int innerHeight = height / (yIndex + 1);BufferedImage innerImage = new BufferedImage(innerWidth, innerHeight, BufferedImage.TYPE_INT_RGB);for(int i = 0; i <= yIndex ; i ++) {for(int j = 0; j <= xIndex ;j++) {for (int y = 0; y < innerHeight; y++) {int[] arrayR = new int[innerWidth];int[] arrayG = new int[innerWidth];int[] arrayB = new int[innerWidth];srcBandR.ReadRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayR);srcBandG.ReadRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayG);srcBandB.ReadRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayB);for (int x = 0; x < innerWidth; x++) {int valueR = arrayR[x];int valueG = arrayG[x];int valueB = arrayB[x];int rgb = (clamp((int) valueR) & 0xff) << 16 | (clamp((int) valueG) & 0xff) << 8| (clamp((int) valueB) & 0xff);innerImage.setRGB(x, y, rgb);}}innerImage = new LaplacianSharpen().lapLaceSharp(innerImage);for (int y = 0; y < innerHeight; y++) {int[] arrayR = new int[innerWidth];int[] arrayG = new int[innerWidth];int[] arrayB = new int[innerWidth];for (int x = 0; x < innerWidth; x++) {int rgb = innerImage.getRGB(x, y);int valueR = (rgb >> 16) & 0xff;int valueG = (rgb >> 8) & 0xff;int valueB = rgb & 0xff;arrayR[x] = valueR;arrayG[x] = valueG;arrayB[x] = valueB;}destBandR.WriteRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayR);destBandG.WriteRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayG);destBandB.WriteRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayB);}}}driver.delete();srcDataset.delete();destDataset.delete();}else {Dataset destDataset = driver.Create(destImage.toString(), width, height, 4);destDataset.SetMetadata(srcDataset.GetMetadata_Dict()); Band srcBandR = srcDataset.GetRasterBand(1);Band srcBandG = srcDataset.GetRasterBand(2);Band srcBandB = srcDataset.GetRasterBand(3);Band destBandR = destDataset.GetRasterBand(1);Band destBandG = destDataset.GetRasterBand(2);Band destBandB = destDataset.GetRasterBand(3);// 讀取信息int xIndex = (int)(width / 26000);int yIndex = (int)(height / 26000);int innerWidth = width / (xIndex + 1);int innerHeight = height / (yIndex + 1);BufferedImage innerImage = new BufferedImage(innerWidth, innerHeight, BufferedImage.TYPE_INT_RGB);for(int i = 0; i <= yIndex ; i ++) {for(int j = 0; j <= xIndex ;j++) {for (int y = 0; y < innerHeight; y++) {int[] arrayR = new int[innerWidth];int[] arrayG = new int[innerWidth];int[] arrayB = new int[innerWidth];srcBandR.ReadRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayR);srcBandG.ReadRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayG);srcBandB.ReadRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayB);for (int x = 0; x < innerWidth; x++) {int valueR = arrayR[x];int valueG = arrayG[x];int valueB = arrayB[x];int rgb = (clamp((int) valueR) & 0xff) << 16 | (clamp((int) valueG) & 0xff) << 8| (clamp((int) valueB) & 0xff);innerImage.setRGB(x, y, rgb);}}innerImage = new LaplacianSharpen().lapLaceSharp(innerImage);for (int y = 0; y < height; y++) {int[] arrayR = new int[innerWidth];int[] arrayG = new int[innerWidth];int[] arrayB = new int[innerWidth];for (int x = 0; x < innerWidth; x++) {int rgb = innerImage.getRGB(x, y);int valueR = (rgb >> 16) & 0xff;int valueG = (rgb >> 8) & 0xff;int valueB = rgb & 0xff;arrayR[x] = valueR;arrayG[x] = valueG;arrayB[x] = valueB;}destBandR.WriteRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayR);destBandG.WriteRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayG);destBandB.WriteRaster(j * innerWidth, i * innerHeight + y, innerWidth, 1, arrayB);}}}Band srcBand = srcDataset.GetRasterBand(4);Band destBand = destDataset.GetRasterBand(4);for (int y = 0; y < height; y++) {int[] array = new int[width];srcBand.ReadRaster(0, y, width, 1, array);destBand.WriteRaster(0, y, width, 1, array);}driver.delete();srcDataset.delete();destDataset.delete();}

處理前影像：

處理后影像：

?

總結

以上是生活随笔為你收集整理的使用gdal和java对TIF格式正射影像进行拉普拉斯锐化的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。