How to downscale a UIImage in IOS by the Data size

Question

I am looking to downscale a UIImage in iOS.

I have seen other questions below and their approach on how to downscale the image by size. R

Answer 1

-(NSData*)testData
{
    UIImage *imageToUpload=[UIImage imageNamed:@"images/lifestyle2.jpg"];
    NSData *imgData=UIImageJPEGRepresentation(imageToUpload,1.0);
    float compressionRate=10;
    while (imgData.length>1024)
    {
        if (compressionRate>0.5)
        {
            compressionRate=compressionRate-0.5;
            imgData=UIImageJPEGRepresentation(imageToUpload,compressionRate/10);
        }
        else
        {
            return imgData;
        }
    }
    return imgData;
}

It maintains image quality not lass than 1MB.

Call it with,

NSData *compressedImageData=[self testData];
NSLog(@"%lu KB",compressedImageData.length);