Simple UIImage with digital camouflage patterns (Woodland, Snow, Desert, Naval, Savanna, Airborne, Ocean, Arid)

EYDigitalCamouflageImage.h

// erkanyildiz
// 20160620-1913
//
// EYDigitalCamouflageImage.h

#import <UIKit/UIKit.h>

typedef enum:NSInteger
{
    EYDCIWoodland,
    EYDCISnow,
    EYDCIDesert,
    EYDCINaval,
    EYDCISavanna,
    EYDCIAirborne,
    EYDCIOcean,
    EYDCIArid,
    EYDigitalCamouflageImagePatternCount
} EYDigitalCamouflageImagePattern;

@interface EYDigitalCamouflageImage : UIImage
+ (UIImage *)imageWithSize:(CGSize)size andPattern:(EYDigitalCamouflageImagePattern)pattern;
@end

EYDigitalCamouflageImage.m

// erkanyildiz
// 20160620-1913
//
// EYDigitalCamouflageImage.m

#import "EYDigitalCamouflageImage.h"

@implementation EYDigitalCamouflageImage
+ (UIImage *)imageWithSize:(CGSize)size andPattern:(EYDigitalCamouflageImagePattern)pattern
{
    const int numberOfPixels = 40;      // number of pixels on the short side of the image
    const int splashMinimum = 5;        // minimum number of pixels in a splash
    const int splashMaximum = 20;       // maximum number of pixels in a splash
    const float reducer = 0.08;         // 0.08 is the magic number
    
    int width = size.width;
    int height = size.height;
    int pixelSize = MIN(width, height) / numberOfPixels;
    int numberOfSplashes = reducer * (width * height / (pixelSize * pixelSize));

    NSArray* colors = [self.class patternColors][pattern % EYDigitalCamouflageImagePatternCount];

    UIGraphicsBeginImageContextWithOptions(size, NO, UIScreen.mainScreen.scale);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGRect bgRect = (CGRect){0, 0, size.width, size.height};
    [(UIColor*)colors[0] set];
    CGContextFillRect(context, bgRect);                 // draw background

    for (int i = 0; i < numberOfSplashes; i++)
    {
        int x = arc4random() % (width / pixelSize);     // random start of splash, x
        int y = arc4random() % (height / pixelSize);    // random start of splash, y
        int c = arc4random() % (colors.count-1) +1;     // randomly chosen splash color (except background color)

        [(UIColor*)colors[c] set];                      // set pixel color

        int splashPixelCount = (int) splashMinimum + arc4random() % (splashMaximum-splashMinimum);
        splashPixelCount *= (colors.count-c);           // color balancing proportional to color index

        for (int j = 0; j < splashPixelCount; j++)
        {
            int dX = (arc4random() % 3) -1;             // random direction of splash, x
            int dY = (arc4random() % 3) -1;             // random direction of splash, y

            x = x + dX;
            y = y + dY;
        
            CGRect pixelRect = (CGRect){x * pixelSize, y * pixelSize, pixelSize, pixelSize};
            CGContextFillRect(context, pixelRect);      // draw pixel
        }
    }
    
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return image;
}


+ (NSArray*)patternColors
{
    #define RGB(r, g, b) [UIColor colorWithRed:(r)/255.0 green:(g)/255.0 blue:(b)/255.0 alpha:1]

    // colors for patterns are ordered from most used (background color) to least used
    NSArray* colors = @[
                            @[    RGB(156,136,109),     //EYDCIWoodland
                                  RGB(88,109,89),
                                  RGB(57,57,59),
                                  RGB(165,157,142)
                             ],
                            @[    RGB(255,255,255),     //EYDCISnow
                                  RGB(151,153,152),
                                  RGB(112, 129,136),
                                  RGB(78,85,77)
                             ],
                            @[    RGB(214,186,146),     //EYDCIDesert
                                  RGB(234,196,169),
                                  RGB(241,214,194),
                                  RGB(148,104,70)
                             ],
                            @[    RGB(165,179,193),     //EYDCINaval
                                  RGB(86,108,117),
                                  RGB(44,65,91),
                                  RGB(31,35,40)
                             ],
                            @[    RGB(100,133,64),      //EYDCISavanna
                                  RGB(42,82,11),
                                  RGB(210,130,7),
                                  RGB(92,18,7)
                             ],
                            @[    RGB(198,205,197),     //EYDCIAirborne
                                  RGB(246,235,218),
                                  RGB(103,118,111),
                                  RGB(75,93,97)
                             ],
                            @[    RGB(71,179,169),      //EYDCIOcean
                                  RGB(0,124,73),
                                  RGB(255,255,255),
                                  RGB(0,0,0)
                             ],
                            @[    RGB(238,225,203),     //EYDCIArid
                                  RGB(119,139,98),
                                  RGB(191,104,73),
                                  RGB(70,68,69)
                             ]
                       ];
    return colors;
}

@end

Woodland

Snow

Desert

Naval

Savanna

Airborne

Ocean

Arid

https://dribbble.com/shots/2544616-Digital-Camouflage-Patterns