/*
* Copyright 2013 Alibaba.com All right reserved. This software is the
* confidential and proprietary information of Alibaba.com ("Confidential
* Information"). You shall not disclose such Confidential Information and shall
* use it only in accordance with the terms of the license agreement you entered
* into with Alibaba.com.
*/
package com.alibaba.simpleimage.analyze.sift.render;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import com.alibaba.simpleimage.analyze.sift.IPixelConverter;
import com.alibaba.simpleimage.analyze.sift.ImagePixelArray;
/**
* 类RenderImage.java的实现描述：TODO 类实现描述
*
* @author axman 2013-6-27 上午10:09:16
*/
public class RenderImage {
private BufferedImage srcImage;
public RenderImage(BufferedImage srcImage){
this.srcImage = srcImage;
}
public int getWidth() {
return this.srcImage.getWidth();
}
public int getHeight() {
return this.srcImage.getHeight();
}
public float scaleWithin(int dim) {
if (this.srcImage.getWidth() <= dim && this.srcImage.getHeight() <= dim) return 1.0f;
float xScala = (float) dim / this.srcImage.getWidth();
float yScala = (float) dim / this.srcImage.getHeight();
float smallestScala = xScala <= yScala ? xScala : yScala; // 取最小的比例
// 创建一个缩小后的位图
BufferedImage bmScalaed = new BufferedImage((int) (this.srcImage.getWidth() * smallestScala + 0.5),
(int) (this.srcImage.getHeight() * smallestScala + 0.5),
BufferedImage.TYPE_INT_ARGB);
Graphics2D g = bmScalaed.createGraphics();
g.drawImage(this.srcImage, 0, 0, (int) (this.srcImage.getWidth() * smallestScala),
(int) (this.srcImage.getHeight() * smallestScala), null);
// TODO,这里可以优化
this.srcImage = bmScalaed;
return smallestScala;
}
public ImagePixelArray toPixelFloatArray(IPixelConverter converter) {
int h = this.srcImage.getHeight();
int w = this.srcImage.getWidth();
ImagePixelArray res = new ImagePixelArray(w, h);
int[] pix = srcImage.getRGB(0, 0, w, h, null, 0, w);
for (int y = 0; y < h; y++) {
for (int x = 0; x < w; x++) {
int c = pix[x + y * w];
int R = (c >> 16) & 0xFF;
int G = (c >> 8) & 0xFF;
int B = (c >> 0) & 0xFF;
if (converter == null) res.data[x + y * w] = (R + G + B) / (255.0f * 3.0f); // 默认实现直接计算，减少h*w次方法调用
else res.data[x + y * w] = converter.convert(R, G, B);
}
}
return res;
}
}