如何在iPhone中裁剪图像

我想和这个问题一样。 在我的应用程序中，我想裁剪图像，就像我们在FaceBook中进行图像裁剪一样，任何人都可以通过好的教程链接或任何示例代码来指导我。 我所提供的链接将完全描述我的要求。

Answer 1

您可以使用任何属性创build新的图像。 这是我的function，女巫这样做。 你只需要使用你自己的新图像参数。 在我的情况下，图像没有被裁剪，我只是有所作为，将像素从原来的地方移动到另一个。 但是，如果用另一个高度和宽度初始化新图像，则可以从所需的旧图像的任意像素范围内复制到新图像：

-(UIImage *)Color:(UIImage *)img { int R; float m_width = img.size.width; float m_height = img.size.height; if (m_width>m_height) R = m_height*0.9; else R = m_width*0.9; int m_wint = (int)m_width; //later, we will need this parameters in float and int. you may just use "(int)" and "(float)" before variables later, and do not implement another ones int m_hint = (int)m_height; CGRect imageRect; //cheking image orientation. we will work with image pixel-by-pixel, so we need to make top side at the top. if(img.imageOrientation==UIImageOrientationUp || img.imageOrientation==UIImageOrientationDown) { imageRect = CGRectMake(0, 0, m_wint, m_hint); } else { imageRect = CGRectMake(0, 0, m_hint, m_wint); } uint32_t *rgbImage = (uint32_t *) malloc(m_wint * m_hint * sizeof(uint32_t)); CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(rgbImage, m_wint, m_hint, 8, m_wint *sizeof(uint32_t), colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast); CGContextSetInterpolationQuality(context, kCGInterpolationHigh); CGContextSetShouldAntialias(context, NO); CGContextTranslateCTM(context, 0, m_hint); CGContextScaleCTM(context, 1.0, -1.0); switch (img.imageOrientation) { case UIImageOrientationRight: { CGContextRotateCTM(context, M_PI / 2); CGContextTranslateCTM(context, 0, -m_wint); }break; case UIImageOrientationLeft: { CGContextRotateCTM(context, - M_PI / 2); CGContextTranslateCTM(context, -m_hint, 0); }break; case UIImageOrientationUp: { CGContextTranslateCTM(context, m_wint, m_hint); CGContextRotateCTM(context, M_PI); } default: break; } CGContextDrawImage(context, imageRect, img.CGImage); CGContextRelease(context); CGColorSpaceRelease(colorSpace); //here is new image. you can change m_wint and m_hint as you whant uint8_t *result = (uint8_t *) calloc(m_wint * m_hint * sizeof(uint32_t), 1); for(int y = 0; y < m_hint; y++) //new m_hint here { float fy=y; double yy = (m_height*( asinf(m_height/(2*R))-asin(((m_height/2)-fy)/R) )) / (2*asin(m_height/(2*R))); // (xx, yy) - coordinates of pixel of OLD image for(int x = 0; x < m_wint; x++) //new m_wint here { float fx=x; double xx = (m_width*( asin(m_width/(2*R))-asin(((m_width/2)-fx)/R) )) / (2*asin(m_width/(2*R))); uint32_t rgbPixel=rgbImage[(int)yy * m_wint + (int)xx]; int intRedSource = (rgbPixel>>24)&255; int intGreenSource = (rgbPixel>>16)&255; int intBlueSource = (rgbPixel>>8)&255; result[(y * (int)m_wint + x) * 4] = 0; result[(y * (int)m_wint + x) * 4 + 1] = intBlueSource; result[(y * (int)m_wint + x) * 4 + 2] = intGreenSource; result[(y * (int)m_wint + x) * 4 + 3] = intRedSource; } } free(rgbImage); colorSpace = CGColorSpaceCreateDeviceRGB(); context = CGBitmapContextCreate(result, m_wint, m_hint, 8, m_wint * sizeof(uint32_t), colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast ); //new m_wint and m_hint as well CGImageRef image1 = CGBitmapContextCreateImage(context); CGContextRelease(context); CGColorSpaceRelease(colorSpace); UIImage *resultUIImage = [UIImage imageWithCGImage:image1]; CGImageRelease(image1); @try { free(result); } @catch (NSException * e) { NSLog(@"proc. Exception: %@", e); } return resultUIImage; } 

Answer 2

CGRect rectImage = CGRectMake（p1.x，p1.y，p2.x – p1.x，p4.y – p1.y）;

 //Create bitmap image from original image data, //using rectangle to specify desired crop area CGImageRef imageRef = CGImageCreateWithImageInRect([imageForCropping CGImage], rectImage); UIImage *croppedImage = [UIImage imageWithCGImage:imageRef]; imageView1 = [[UIImageView alloc] initWithFrame:CGRectMake(p1.x, p1.y,p2.x-p1.x p4.y-p1.y)]; imageView1.image = croppedImage; [self.view addSubview:imageView1]; CGImageRelease(imageRef);