Java? ????? ?? ???? ?? ??? ???? ??

BufferedImage? ?? ??? ??? ?? ??? ??? ?????. ??? ??? ?? ? ??? ?? ??? ????? ????? ? ???? ?? ? ????. Java?? ?? ???? ???? ?? ? ?? ?? ?? ??? ????.

1. BufferedImage? getRGB() ??? ??:

   ? ???? ?? ??? ??? ?? ??? ?????. ??, ???, ?? ? ??? ?? ?????. ? ?? ??? ????? ?? ??? ????? ?? ??? ??? ????? ??? ??? ????.

2. ?? ??? ?? ???:

   ?? ??? ?? ?????? ?? ??? ??? ? ????.

   byte[] pixels = ((DataBufferByte) bufferedImage.getRaster().getDataBuffer()).getData();

   ? ??? ??? ?????. ? ??? ???, ??, ??? ?? ??????. ?? ??? ??? ??? ???? ?????. ? ??? ? ??? ??? ??? ????? getRGB()? ???? ??? ?? ????.

?? ??

????? ?? ?? ??? ?????. ? ?? ?? ??? ?? ??. getRGB()?? ?? ?? ???? ???? ??? ???? ??? ? ??? 90% ?? ???????. ??? ???? ?? ?? ??? ??? ????.

import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.io.IOException;

public class PerformanceComparison {

    public static void main(String[] args) throws IOException {
        BufferedImage image = ImageIO.read(PerformanceComparison.class.getResource("large_image.jpg"));

        // Using getRGB()
        long startTime = System.nanoTime();
        int[][] resultRGB = convertTo2DUsingGetRGB(image);
        long endTime = System.nanoTime();
        System.out.println("getRGB(): " + toString(endTime - startTime));

        // Using direct array access
        startTime = System.nanoTime();
        int[][] resultArray = convertTo2DWithoutUsingGetRGB(image);
        endTime = System.nanoTime();
        System.out.println("Direct Array Access: " + toString(endTime - startTime));
    }

    private static int[][] convertTo2DUsingGetRGB(BufferedImage image) {
        int width = image.getWidth();
        int height = image.getHeight();
        int[][] result = new int[height][width];

        for (int row = 0; row < height; row++) {
            for (int col = 0; col < width; col++) {
                result[row][col] = image.getRGB(col, row);
            }
        }

        return result;
    }

    private static int[][] convertTo2DWithoutUsingGetRGB(BufferedImage image) {
        final byte[] pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
        final int width = image.getWidth();
        final int height = image.getHeight();
        int[][] result = new int[height][width];

        int index = 0;
        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                int alpha = pixels[index++] & 0xFF;
                int blue = pixels[index++] & 0xFF;
                int green = pixels[index++] & 0xFF;
                int red = pixels[index++] & 0xFF;
                result[y][x] = (alpha << 24) | (blue << 16) | (green << 8) | red;
            }
        }

        return result;
    }

    private static String toString(long nanos) {
        return String.format("%d min %d s %d ms", nanos / 60000000000L, (nanos % 60000000000L) / 1000000000L, (nanos % 1000000000L) / 1000000L);
    }
}

?? ???? ???? ?? ?? ?? ??? ?? ????? ?? ?? ???? ?? ? ???? ?? ???? ?? ?????.

? ??? Java? BufferedImage?? ?? ???? ?? ??? ????? ???? ??? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!