UIImage+ChameleonPrivate.m

//
//  UIImage+ChameleonPrivate.m
//  Chameleon
//
//  Created by Vicc Alexander on 6/8/15.
//  Copyright (c) 2015 Vicc Alexander. All rights reserved.
//

#import "UIImage+ChameleonPrivate.h"

@implementation UIImage (ChameleonPrivate)

// Would not have been possible without - http://stackoverflow.com/a/1262893
+ (UIColor *)colorFromImage:(UIImage *)image atPoint:(CGPoint)point {
    
    //Encapsulate our image
    CGImageRef imageRef = image.CGImage;
    NSUInteger width = CGImageGetWidth(imageRef);
    NSUInteger height = CGImageGetHeight(imageRef);
    
    //Specify the colorspace we're in
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    
    //Extract the data we need
    unsigned char *rawData = calloc(height * width * 4, sizeof(unsigned char));
    NSUInteger bytesPerPixel = 4;
    NSUInteger bytesPerRow = bytesPerPixel * width;
    NSUInteger bitsPerComponent = 8;
    CGContextRef context = CGBitmapContextCreate(rawData, width, height, bitsPerComponent, bytesPerRow,
                                                 colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
    //Release colorspace
    CGColorSpaceRelease(colorSpace);
    
    //Draw and release image
    CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
    CGContextRelease(context);
    
    //rawData now contains the image data in RGBA8888
    NSInteger byteIndex = (bytesPerRow * point.y) + (point.x * bytesPerPixel);
    
    //Define our RGBA values
    CGFloat red = (rawData[byteIndex] * 1.f) / 255.f;
    CGFloat green = (rawData[byteIndex + 1] * 1.f) / 255.f;
    CGFloat blue = (rawData[byteIndex + 2] * 1.f) / 255.f;
    CGFloat alpha = (rawData[byteIndex + 3] * 1.0) / 255.f;
    
    //Free our rawData
    free(rawData);
    
    //Return color
    return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
}

+ (UIImage *)imageWithImage:(UIImage *)image scaledToSize:(CGSize)newSize {
    
    UIGraphicsBeginImageContextWithOptions(newSize, NO, 1.0);
    [image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}

#pragma mark - Instance Methods

- (UIImage *)imageScaledToSize:(CGSize)newSize {
    
    UIGraphicsBeginImageContextWithOptions(newSize, NO, 1.0);
    [self drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}

@end