传输文件,或者设置头像,我们一般都会检查原始图片的大小,作缩放处理。
常用的Java版缩放图片代码:
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public Bitmap getZoomImage(Bitmap src, int desW, int desH)
{
Bitmap desImg = null;
int srcW = src.getWidth(); // 原始图像宽
int srcH = src.getHeight(); // 原始图像高
int[] srcBuf = new int[srcW * srcH]; // 原始图片像素信息缓存
src.getPixels(srcBuf, 0, srcW, 0, 0, srcW, srcH);
// 计算插值表
int[] tabY = new int[desH];
int[] tabX = new int[desW];
int sb = 0;
int db = 0;
int tems = 0;
int temd = 0;
int distance = srcH > desH ? srcH : desH;
for (int i = 0; i <= distance; i++)
{/* 垂直方向 */
tabY[db] = sb;
tems += srcH;
temd += desH;
if (tems > distance)
{
tems -= distance;
sb++;
}
if (temd > distance)
{
temd -= distance;
db++;
}
}
sb = 0;
db = 0;
tems = 0;
temd = 0;
distance = srcW > desW ? srcW : desW;
for (int i = 0; i <= distance; i++)
{/* 水平方向 */
tabX[db] = (short) sb;
tems += srcW;
temd += desW;
if (tems > distance)
{
tems -= distance;
sb++;
}
if (temd > distance)
{
temd -= distance;
db++;
}
}
// 生成放大缩小后图形像素
int[] desBuf = new int[desW * desH];
int dx = 0;
int dy = 0;
int sy = 0;
int oldy = -1;
for (int i = 0; i < desH; i++)
{
if (oldy == tabY[i])
{
System.arraycopy(desBuf, dy - desW, desBuf, dy, desW);
}
else
{
dx = 0;
for (int j = 0; j < desW; j++)
{
desBuf[dy + dx] = srcBuf[sy + tabX[j]];
dx++;
}
sy += (tabY[i] - oldy) * srcW;
}
oldy = tabY[i];
dy += desW;
}
// 生成图片
desImg = Bitmap.createBitmap(desBuf, desW, desH, Bitmap.Config.ARGB_8888);
return desImg;
}
public Bitmap getZoomImage(Bitmap src, int desW, int desH)
{
Bitmap desImg = null;
int srcW = src.getWidth(); // 原始图像宽
int srcH = src.getHeight(); // 原始图像高
int[] srcBuf = new int[srcW * srcH]; // 原始图片像素信息缓存
src.getPixels(srcBuf, 0, srcW, 0, 0, srcW, srcH);
// 计算插值表
int[] tabY = new int[desH];
int[] tabX = new int[desW];
int sb = 0;
int db = 0;
int tems = 0;
int temd = 0;
int distance = srcH > desH ? srcH : desH;
for (int i = 0; i <= distance; i++)
{/* 垂直方向 */
tabY[db] = sb;
tems += srcH;
temd += desH;
if (tems > distance)
{
tems -= distance;
sb++;
}
if (temd > distance)
{
temd -= distance;
db++;
}
}
sb = 0;
db = 0;
tems = 0;
temd = 0;
distance = srcW > desW ? srcW : desW;
for (int i = 0; i <= distance; i++)
{/* 水平方向 */
tabX[db] = (short) sb;
tems += srcW;
temd += desW;
if (tems > distance)
{
tems -= distance;
sb++;
}
if (temd > distance)
{
temd -= distance;
db++;
}
}
// 生成放大缩小后图形像素
int[] desBuf = new int[desW * desH];
int dx = 0;
int dy = 0;
int sy = 0;
int oldy = -1;
for (int i = 0; i < desH; i++)
{
if (oldy == tabY[i])
{
System.arraycopy(desBuf, dy - desW, desBuf, dy, desW);
}
else
{
dx = 0;
for (int j = 0; j < desW; j++)
{
desBuf[dy + dx] = srcBuf[sy + tabX[j]];
dx++;
}
sy += (tabY[i] - oldy) * srcW;
}
oldy = tabY[i];
dy += desW;
}
// 生成图片
desImg = Bitmap.createBitmap(desBuf, desW, desH, Bitmap.Config.ARGB_8888);
return desImg;
}
常用的Android版缩放图片代码: