《IOS开发系列教程》RGB生成UIImage

《IOS开发系列教程》RGB生成UIImage

 

IOS要求的像素格式是

RGBA

而不是

RGB

因此如果如果拿到的数据格式是RGB,那么需要转换成RGBA,

RGB–>RGBA–>UIImage

再使用下面的语法显示图片:

UIImageViewer.image = UIImage

 

下面给出一个例子:

const size_t Height = 10;
const size_t Area = Width * Height;
const size_t ComponentsPerPixel = 4; // rgba

uint8_t pixelData[Area * ComponentsPerPixel];

// fill the pixels with a lovely opaque blue gradient:
for (size_t i=0; i < Area; ++i) {
    const size_t offset = i * ComponentsPerPixel;
    pixelData[offset] = i;
    pixelData[offset+1] = i;
    pixelData[offset+2] = i + i; // enhance blue
    pixelData[offset+3] = UINT8_MAX; // opaque
}

// create the bitmap context:
const size_t BitsPerComponent = 8;
const size_t BytesPerRow=((BitsPerComponent * Width) / 8) * ComponentsPerPixel;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef gtx = CGBitmapContextCreate(&pixelData[0], Width, Height, BitsPerComponent, BytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast);

// create the image:
CGImageRef toCGImage = CGBitmapContextCreateImage(gtx);
UIImage * uiimage = [[UIImage alloc] initWithCGImage:toCGImage];

 

 

版权所有,禁止转载. 如需转载,请先征得博主的同意,并且表明文章转载自:IT夜班车,否则按侵权处理.

    分享到:

Leave a Reply

Your email address will not be published. Required fields are marked *