Qt/C++ 改变图片亮度算法 注意是算法

QImage Bright1(QImage &image,int brightness)

{

uchar *line =image.scanLine(0);

uchar *pixel = line;

for (int y = 0; y < image.height(); ++y)
{
pixel = line;
for (int x = 0; x < image.width(); ++x)
{
*pixel = qBound(0, *pixel + brightness, 255);
*(pixel + 1) = qBound(0, *(pixel + 1) + brightness, 255);
*(pixel + 2) = qBound(0, *(pixel + 2) + brightness, 255);
pixel += 4;
}

line += image.bytesPerLine();
}
return image;

}

QImage Bright2(QImage &image,int brightness)

{

QImage origin = image;

QColor oldColor;

int delta = brightness;

int r=0,g=0,b=0;

uchar *line =image.scanLine(0);

uchar *pixel = line;

QImage * newImage = new QImage(origin.width(), origin.height(), QImage::Format_ARGB32);

for(int y=0; yheight(); ++y)

{

for(int x=0; xwidth(); ++x)

{

oldColor = QColor(image.pixel(x,y));

r = oldColor.red() + brightness;

g = oldColor.green() + brightness;

b = oldColor.blue() + brightness;

newImage->setPixel(x,y, qRgb(r,g,b));

}

}

return *newImage;

}

QImage Bright3(QImage& source, int factor)

{

if (factor < -255 || factor > 255)

return source;

int red, green, blue;
int pixels = source.width() * source.height();
unsigned int *data = (unsigned int *)source.bits();
for (int i = 0; i < pixels; ++i)
{
red= qRed(data[i])+ factor;
red = (red < 0x00) ? 0x00 : (red > 0xff) ? 0xff : red;
green= qGreen(data[i])+factor;
green = (green < 0x00) ? 0x00 : (green > 0xff) ? 0xff : green;
blue= qBlue(data[i])+factor;
blue =  (blue  < 0x00) ? 0x00 : (blue  > 0xff) ? 0xff : blue ;
data[i] = qRgba(red, green, blue, qAlpha(data[i]));
}
return source;

}

总体思路就是获取每一个像素点，再通过一个什么什么算法计算出该出该像素的值,再重新设置该像素点的值，差不多就是这样

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文章来源：http://blog.csdn.net/what951006