//調用 UIImage *qrcode = [self createNonInterpolatedUIImageFormCIImage:[self createQRForString:@"http://www.baidu.com"] withSize:190.0f]; UIImage *customQrcode = [self imageBlackToTransparent:qrcode withRed:0.0f andGreen:0.0f andBlue:0.0f]; self.erweimaImg.image = customQrcode;
#pragma mark - InterpolatedUIImage - (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size { CGRect extent = CGRectIntegral(image.extent); CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent)); // create a bitmap image that we'll draw into a bitmap context at the desired size; size_t width = CGRectGetWidth(extent) * scale; size_t height = CGRectGetHeight(extent) * scale; CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray(); CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone); CIContext *context = [CIContext contextWithOptions:nil]; CGImageRef bitmapImage = [context createCGImage:image fromRect:extent]; CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone); CGContextScaleCTM(bitmapRef, scale, scale); CGContextDrawImage(bitmapRef, extent, bitmapImage); // Create an image with the contents of our bitmap CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef); // Cleanup CGContextRelease(bitmapRef); CGImageRelease(bitmapImage); return [UIImage imageWithCGImage:scaledImage]; } #pragma mark - QRCodeGenerator - (CIImage *)createQRForString:(NSString *)qrString { // Need to convert the string to a UTF-8 encoded NSData object NSData *stringData = [qrString dataUsingEncoding:NSUTF8StringEncoding]; // Create the filter CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"]; // Set the message content and error-correction level [qrFilter setValue:stringData forKey:@"inputMessage"]; [qrFilter setValue:@"M" forKey:@"inputCorrectionLevel"]; // Send the image back return qrFilter.outputImage; } #pragma mark - imageToTransparent void ProviderReleaseData (void *info, const void *data, size_t size){ free((void*)data); } - (UIImage*)imageBlackToTransparent:(UIImage*)image withRed:(CGFloat)red andGreen:(CGFloat)green andBlue:(CGFloat)blue{ const int imageWidth = image.size.width; const int imageHeight = image.size.height; size_t bytesPerRow = imageWidth * 4; uint32_t* rgbImageBuf = (uint32_t*)malloc(bytesPerRow * imageHeight); // create context CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast); CGContextDrawImage(context, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage); // traverse pixe int pixelNum = imageWidth * imageHeight; uint32_t* pCurPtr = rgbImageBuf; for (int i = 0; i < pixelNum; i++, pCurPtr++){ if ((*pCurPtr & 0xFFFFFF00) < 0x99999900){ // change color uint8_t* ptr = (uint8_t*)pCurPtr; ptr[3] = red; //0~255 ptr[2] = green; ptr[1] = blue; }else{ uint8_t* ptr = (uint8_t*)pCurPtr; ptr[0] = 0; } } // context to image CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, rgbImageBuf, bytesPerRow * imageHeight, ProviderReleaseData); CGImageRef imageRef = CGImageCreate(imageWidth, imageHeight, 8, 32, bytesPerRow, colorSpace, kCGImageAlphaLast | kCGBitmapByteOrder32Little, dataProvider, NULL, true, kCGRenderingIntentDefault); CGDataProviderRelease(dataProvider); UIImage* resultUIImage = [UIImage imageWithCGImage:imageRef]; // release CGImageRelease(imageRef); CGContextRelease(context); CGColorSpaceRelease(colorSpace); return resultUIImage; }