iPhone : 비디오 미리보기 이미지 만들기

Question

UIImagePickerController didFinishPickingMediaWithInfo에서 제공하는 정보에서 어떻게 축소판 이미지를 만들 수 있습니까?

Answer 1

static inline double radians (double degrees) { 
    return degrees * M_PI/180; 
} 

- (UIImage*) imageByScalingToSize:(CGSize)targetSize image:(UIImage*)image { 
    UIImage* sourceImage = image; 
    CGFloat targetWidth = targetSize.width; 
    CGFloat targetHeight = targetSize.height; 

    CGFloat sourceHeight = image.size.height; 
    CGFloat sourceWidth = image.size.width; 

    if(sourceHeight < sourceWidth) { 
     CGFloat ratio = sourceWidth/sourceHeight; 
     targetWidth = ratio*targetHeight; 
    }else if(sourceHeight > sourceWidth) { 
     CGFloat ratio = sourceHeight/sourceWidth; 
     targetHeight = ratio*targetWidth; 
    } 

    CGImageRef imageRef = [sourceImage CGImage]; 
    CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef); 
    CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef); 

    if (bitmapInfo == kCGImageAlphaNone) { 
     bitmapInfo = kCGImageAlphaNoneSkipLast; 
    } 

    CGContextRef bitmap; 
    if(sourceImage.imageOrientation == UIImageOrientationRight) { 
     float temp = targetWidth; 
     targetWidth = targetHeight; 
     targetHeight = temp; 
    } 

    if (sourceImage.imageOrientation == UIImageOrientationUp || sourceImage.imageOrientation == UIImageOrientationDown) { 
     bitmap = CGBitmapContextCreate(NULL, targetWidth, targetHeight, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo); 
    } else { 
     bitmap = CGBitmapContextCreate(NULL, targetHeight, targetWidth, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo); 
    } 

    if (sourceImage.imageOrientation == UIImageOrientationLeft) { 
     CGContextRotateCTM (bitmap, radians(90)); 
     CGContextTranslateCTM (bitmap, 0, -targetHeight); 
    } else if (sourceImage.imageOrientation == UIImageOrientationRight) { 
     CGContextRotateCTM (bitmap, radians(-90)); 
     CGContextTranslateCTM (bitmap, -targetWidth, 0); 
    } else if (sourceImage.imageOrientation == UIImageOrientationUp) { 
     // NOTHING 
    } else if (sourceImage.imageOrientation == UIImageOrientationDown) { 
     CGContextTranslateCTM (bitmap, targetWidth, targetHeight); 
     CGContextRotateCTM (bitmap, radians(-180.)); 
    } 

    CGContextDrawImage(bitmap, CGRectMake(0, 0, targetWidth, targetHeight), imageRef); 
    CGImageRef ref = CGBitmapContextCreateImage(bitmap); 
    UIImage *newImage1 = [UIImage imageWithCGImage:ref]; 

    CGContextRelease(bitmap); 
    CGImageRelease(ref); 

    return newImage1; 
} 

엄지 이미지를 만들려는 크기 만 지정하면됩니다.