イメージオブジェクトの読み込みと書き込みのソースコードとなります。

ImageReadWriteTest.java. 

package com.book.jocl.image;

import static org.jocl.CL.*;

import org.jocl.CL;
import org.jocl.Pointer;
import org.jocl.Sizeof;
import org.jocl.cl_command_queue;
import org.jocl.cl_context;
import org.jocl.cl_context_properties;
import org.jocl.cl_device_id;
import org.jocl.cl_image_desc;
import org.jocl.cl_image_format;
import org.jocl.cl_kernel;
import org.jocl.cl_mem;
import org.jocl.cl_platform_id;
import org.jocl.cl_program;

import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
import java.awt.*;
import javax.swing.*;
import javax.imageio.*;
import java.io.*;
import java.net.URL;
import java.nio.file.Paths;
import java.util.Scanner;


public class ImageReadWriteTest {
        private static final String IMAGE_PATH = "SAMPLE.png";
        private static final String KERNEL_PATH = "image.cl";
        private static final String KERNEL_FUNC = "image_filter";

    private static cl_context context;
    private static cl_command_queue queue;
    private static cl_program program;
    private static cl_kernel kernel;

    private static ImageIcon img;
    private static int width;
    private static int height;

        public static void main(String[] args) throws Exception {

                CL.setExceptionsEnabled(true);

                cl_platform_id platform[] = new cl_platform_id[1];
                clGetPlatformIDs(1,  platform, null);
                cl_device_id device[] = new cl_device_id[1];
                int num_devices[] = new int[1];
                clGetDeviceIDs(platform[0], CL_DEVICE_TYPE_GPU, 1, device, num_devices);
                cl_context_properties props = new cl_context_properties();
                props.addProperty(CL_CONTEXT_PLATFORM, platform[0]);
                context = clCreateContext(props, 1, device, null, null, null);
                queue = clCreateCommandQueue(context, device[0], 0, null);

                StringBuffer sb = new StringBuffer();
                URL resource = ImageReadWriteTest.class.getResource(KERNEL_PATH);
                String path = Paths.get(resource.toURI()).toFile().getAbsolutePath();
                System.out.println(path);
                Scanner sc = new Scanner(new File(path));
                while(sc.hasNext()) {
                        sb.append(sc.nextLine() + "\n");
                }
        program = clCreateProgramWithSource(context,
                1, new String[]{sb.toString()}, null, null);

        clBuildProgram(program, 0, null, null, null, null);

        kernel = clCreateKernel(program, KERNEL_FUNC, null);

                URL imgResource = ImageReadWriteTest.class.getResource(IMAGE_PATH);

                String imgPath = Paths.get(imgResource.toURI()).toFile().getAbsolutePath();
                System.out.println(imgPath);
        img = new ImageIcon(imgResource);

        width = img.getIconWidth();
        height = img.getIconHeight();

        BufferedImage bimg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics g = bimg.createGraphics();
        img.paintIcon(null, g, 0,0);
        g.dispose();
        DataBufferInt dbb = (DataBufferInt)bimg.getRaster().getDataBuffer();
            int[] intArray = dbb.getData();
            System.out.println(intArray.length);

        cl_image_format format = new cl_image_format();
        format.image_channel_data_type = CL_UNORM_INT8;
        format.image_channel_order = CL_RGBA;
        cl_image_desc desc = new cl_image_desc();
        desc.image_height = img.getIconHeight();
        desc.image_width = img.getIconWidth();
        desc.num_mip_levels = 0;
        desc.num_samples = 0;
        desc.image_type = CL_MEM_OBJECT_IMAGE2D;

        cl_mem img_mem = clCreateImage(context,
                        CL_MEM_READ_ONLY | CL_MEM_ALLOC_HOST_PTR,
                        format,
                        desc,
                        null,
                        null);

        clEnqueueWriteImage(queue,
            img_mem,
            CL_TRUE,
            new long[]{0,0,0},
            new long[]{width,height,1},0,0,
            Pointer.to(intArray),
            0, null, null); //(1)

        int[] dstArray = new int[90000];

        clEnqueueReadImage(queue,
            img_mem,
            CL_TRUE,
            new long[]{0,0,0},
            new long[]{300,300,1},0, 0,
            Pointer.to(dstArray),
            0, null, null); //(2)

                BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
                image.setRGB(0, 0, width, height, dstArray, 0, width);

                System.out.println(width+"-"+height);

                resource = ImageReadWriteTest.class.getResource("./");
                path = Paths.get(resource.toURI()).toFile().getAbsolutePath();
                System.out.println(path+"/writeimage.png");
        ImageIO.write(image, "png", new File(path+"/writeimage.png"));

        clReleaseMemObject(img_mem);
                clReleaseDevice(device[0]);
                clReleaseContext(context);
                clReleaseCommandQueue(queue);
                clReleaseProgram(program);

        }

}