使圖像適合長方形

Question

如果我有一個我知道高度和寬度的圖像，如何將它放在具有最大可能尺寸的矩形中而不會拉伸圖像。

僞代碼已經足夠了（但我打算在Java中使用它）。

謝謝。

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所以，根據答案，我寫了這個：但它不起作用。我做錯了什麼？

double imageRatio = bi.getHeight()/bi.getWidth(); 
double rectRatio = getHeight()/getWidth(); 
if (imageRatio < rectRatio) 
{ 
    // based on the widths 
    double scale = getWidth()/bi.getWidth(); 
    g.drawImage(bi, 0, 0, (int) (bi.getWidth() * scale), (int) (bi.getHeight() * scale), this); 
} 
if (rectRatio < imageRatio) 
{ 
    // based on the height 
    double scale = getHeight()/bi.getHeight(); 
    g.drawImage(bi, 0, 0 , (int) (bi.getWidth() * scale), (int) (bi.getHeight() * scale), this); 
} 

Answer 1

確定兩者的縱橫比（高度除以寬度，比方說，這麼高，瘦矩形的縱橫比> 1）。

如果矩形的長寬比大於圖像的寬高比，則根據寬度（矩形寬度/圖像寬度）均勻縮放圖像。

如果矩形的縱橫比小於圖像的縱橫比，則根據高度（矩形高度/圖像高度）均勻縮放圖像。

Answer 2

這裏是我的兩分錢：

/** 
* Calculate the bounds of an image to fit inside a view after scaling and keeping the aspect ratio. 
* @param vw container view width 
* @param vh container view height 
* @param iw image width 
* @param ih image height 
* @param neverScaleUp if <code>true</code> then it will scale images down but never up when fiting 
* @param out Rect that is provided to receive the result. If <code>null</code> then a new rect will be created 
* @return Same rect object that was provided to the method or a new one if <code>out</code> was <code>null</code> 
*/ 
private static Rect calcCenter (int vw, int vh, int iw, int ih, boolean neverScaleUp, Rect out) { 

    double scale = Math.min((double)vw/(double)iw, (double)vh/(double)ih); 

    int h = (int)(!neverScaleUp || scale<1.0 ? scale * ih : ih); 
    int w = (int)(!neverScaleUp || scale<1.0 ? scale * iw : iw); 
    int x = ((vw - w)>>1); 
    int y = ((vh - h)>>1); 

    if (out == null) 
     out = new Rect(x, y, x + w, y + h); 
    else 
     out.set(x, y, x + w, y + h); 

    return out; 
}