降低UIImage的DPI分辨率

Question

我正在使用mfmailcomposeviewcontroller通过电子邮件发送图像:

[mailComposer addAttachmentData:UIImageJPEGRepresentation(self.editedImageView.image, 1.0f)
                           mimeType:@"image/jpeg" 
                           fileName:@"yourPhotoWithBestGlasses.jpg"];

我在电子邮件中看到的图片是160 DPI分辨率.

如何在不降低质量的情况下将其降低到72 DPI,降低kb尺寸？

Answer 1

NSData = UIImageJPEGRepresentation(rightPhoto, 0.5);

然后initwithdata回来.

详细代码

NSData *imageData = UIImageJPEGRepresentation(originalImage, 0.5);

UIImage *tImage = [[UIImage alloc] initWithData:imageData];

originalImage = [tImage copy];

[tImage release];