#include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> using namespace cv; int main() { //Read file and load to variable Mat image = imread("lenag.jpg"); //If read failure if(!image.data) { return -1; } //Create a window to display the image namedWindow("Original image"); //Show the image imshow("Original image",image); //Create another image for result Mat result; flip(image, result, 1); //1=horizontal, 0=vertical, -1=both //Create a window to display the image namedWindow("Output image"); //Show the image imshow("Output image",result); //Wait for user to press any key waitKey(0); return 0; }
public void run(ImageProcessor ip){ int MN = ip.getPixelCount(); for(int p=0;p<MN;p++){ int v = ip.get(p); v = (int) Math.round(1.5*v); //50% increase of contrast if(v>255) //clamp max v = 255; v = 255-v; //inverse ip.set(p,v); } }
public void run(ImageProcessor ip){ int K = 256; //gray level int[] LUT = new int[K]; //lookup table for(int i=0;i<K;i++){ int v = (int) Math.round(i*1.5); //increase contrast 50% if(v>255) //clamp max v = 255; v = 255-v; //inverse LUT[i] = v; } //look for value in lookup table int MN = ip.getPixelCount(); for(int p=0;p<MN;p++){ ip.set(p,LUT[ip.get(p)]); } //ip.applyTable(LUT); is better for this loop }
import ij.IJ; import ij.ImagePlus; import ij.plugin.filter.PlugInFilter; import ij.process.ImageProcessor; public class My_Threshold implements PlugInFilter { public int setup(String arg, ImagePlus imp) { return DOES_8G; //accept only 8-bit grayscale image } public void run(ImageProcessor ip) { int th = (int) IJ.getNumber("Threshold value (0-255)",100); if(th==IJ.CANCELED) //if click cancel return; if((th<0) || (th>255)){ IJ.error("Error","0-255 only"); return; } ip.threshold(th); //thresholding /* int MN = ip.getPixelCount(); for(int p=0;p<MN;p++){ if(ip.get(p)<=th) ip.set(p,0); else ip.set(p,255); } */ } }
//Plugin to change contrast import ij.IJ; import ij.ImagePlus; import ij.plugin.filter.PlugInFilter; import ij.process.ImageProcessor; public class My_Contrast implements PlugInFilter { public int setup(String arg, ImagePlus imp) { return DOES_8G; //accept only 8-bit grayscale image } public void run(ImageProcessor ip) { double ad = IJ.getNumber("Adjust percent of contrast",50); if(ad==IJ.CANCELED) //if click cancel return; int MN = ip.getPixelCount(); for(int p=0;p<MN;p++) { //contrast int v = (int)(ip.get(p)*(1+ad/100)); if(v>255) //clamp max value v = 255; if(v<0) //clamp min value v = 0; ip.set(p,v); } } }
public void run(ImageProcessor ip) { double ad = IJ.getNumber("Adjust value of brigtness",50); if(ad==IJ.CANCELED) //if click cancel return; int MN = ip.getPixelCount(); for(int p=0;p<MN;p++) { //brightness int v = (int) (ip.get(p) + ad); if(v>255) //clamp max value v = 255; if(v<0) //clamp min value v = 0; ip.set(p,v); } }
public void run(String arg) { // log IJ.log("Use log method to debug variable"); int a = 99; IJ.log("a = "+a); }
public void run(String arg) { // show text in status bar IJ.showStatus("Message at status bar"); }
//Plugin to compute histogram import ij.ImagePlus; import ij.plugin.filter.PlugInFilter; import ij.process.ImageProcessor; import ij.process.ByteProcessor; public class My_Histogram implements PlugInFilter { public int setup(String arg, ImagePlus im) { return DOES_8G + NO_CHANGES; //accept only 8-bit grayscale image } public void run(ImageProcessor ip) { int[] H = new int[256]; /* int MN = ip.getPixelCount(); for(int p=0;p<MN;p++) { int v = ip.get(p); H[v] += 1; } */ H = ip.getHistogram(); //built-in method } }
//find max of histogram bin int max=H[0]; for(int b=1;b<256;b++) { if(max<H[b]) max=H[b]; } //create the image of histogram //prepare blank area of w=256 h=100 ImageProcessor histip = new ByteProcessor(256,100); histip.setValue(255) ; // white = 255 histip.fill(); // clear this image //draw histogram bins for(int b=0;b<256;b++) { int hh = (int)(100.0*H[b]/max); //normalized bin's height for(int r=0;r<hh;r++) { histip.set(b,99-r,0); //plot black points } } // display the histogram image: ImagePlus histim = new ImagePlus("Histogram", histip); histim.show();
//Plugin to invert a grayscale image import ij.ImagePlus; import ij.plugin.filter.PlugInFilter; import ij.process.ImageProcessor; import ij.process.ByteProcessor; // _ in the class name = plugin public class My_Invert implements PlugInFilter { public int setup(String arg, ImagePlus im) { return DOES_8G; //accept only 8-bit grayscale image } public void run(ImageProcessor ip) { //1. use getPixel, putPixel to access each pixel //they check image boundary+invoke function call, slowest int w = ip.getWidth(); int h = ip.getHeight(); //for each pixel for(int x=0;x<w;x++) for(int y=0;y<h;y++) ip.putPixel(x,y,255-ip.getPixel(x,y)); /* //2. use get,set which do not check boundary //still invoke function, faster int w = ip.getWidth(); int h = ip.getHeight(); //for each pixel for(int x=0;x<w;x++) for(int y=0;y<h;y++) ip.set(x,y,255-ip.get(x,y)); */ /* //3. use get,set with 1d indices //only 1 loop, invoke function, more faster int MN = ip.getPixelCount(); //total pixels for(int p=0;p<MN;p++) ip.set(p, 255-ip.get(p)); */ /* //4. use getPixels to directly process pixel array //direct access, no function invocation //fastest but more memory need //check if ip is ByteProcessor (0-255) if(!(ip instanceof ByteProcessor)) return; if(!(ip.getPixels() instanceof byte[])) return; //dump to array but by reference!!! byte[] pixels = (byte[]) ip.getPixels(); int MN = ip.getPixelCount(); for(int p=0;p<MN;p++) { int v = 0xFF & pixels[p]; //convert to integer v = 255-v; pixels[p] = (byte) (0xFF & v); //to byte } */ } }
//Plugin to invert a grayscale image import ij.ImagePlus; import ij.plugin.filter.PlugInFilter; import ij.process.ImageProcessor; import ij.process.ByteProcessor; // _ in the class name = plugin public class My_Invert implements PlugInFilter { public int setup(String arg, ImagePlus im) { return DOES_8G; //accept only 8-bit grayscale image } public void run(ImageProcessor ip) { //1. use getPixel, putPixel to access each pixel //they check image boundary+invoke function call, slowest //0.015 second int w = ip.getWidth(); int h = ip.getHeight(); //for each pixel for(int x=0;x<w;x++) for(int y=0;y<h;y++) ip.putPixel(x,y,255-ip.getPixel(x,y)); } }
