返回一张图片的主色调

来源：互联网发布：seo效果明显吗编辑：程序博客网时间：2024/05/23 01:17

#import <UIKit/UIKit.h>@interface UIColor (YKD)/** *  返回一张图片的主色调 */+ (UIColor *)mostColorWithImage:(UIImage *)image;@end

////  UIColor+YKD.m#import "UIColor+YKD.h"@implementation UIColor (YKD)+ (UIColor *)mostColorWithImage:(UIImage *)image{    // 1.先把图片缩小，加快计算速度，但越小结果误差可能越大    CGSize thumbSize = CGSizeMake(50, 50);        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();        CGContextRef context = CGBitmapContextCreate(NULL, thumbSize.width, thumbSize.height, 8, thumbSize.width*4, colorSpace, kCGImageAlphaPremultipliedLast);        CGRect drawRect = CGRectMake(0, 0, thumbSize.width, thumbSize.height);    CGContextDrawImage(context, drawRect, image.CGImage);    CGColorSpaceRelease(colorSpace);        // 2.取每个点的像素值    unsigned char *data = CGBitmapContextGetData(context);    if (data == NULL) {        return nil;    }    NSCountedSet *cls = [NSCountedSet setWithCapacity:thumbSize.width*thumbSize.height];    for (int x=0; x<thumbSize.width; x++) {        for (int y=0; y<thumbSize.height; y++) {            int offset = 4 * (x*y);            int red = data[offset];            int green = data[offset +1];            int blue = data[offset+2];            int alpha =  data[offset+3];                        NSArray *clr=@[@(red),@(green),@(blue),@(alpha)];            [cls addObject:clr];        }    }    CGContextRelease(context);        // 3.找到出现次数最多的那个颜色    NSEnumerator *enumerator = [cls objectEnumerator];    NSArray *curColor = nil;        NSArray *MaxColor=nil;    NSUInteger MaxCount=0;        while ( (curColor = [enumerator nextObject]) != nil )    {        NSUInteger tmpCount = [cls countForObject:curColor];                if ( tmpCount < MaxCount ) continue;                MaxCount=tmpCount;        MaxColor=curColor;    }        // 4.返回    return [UIColor colorWithRed:([MaxColor[0] intValue]/255.0f) green:([MaxColor[1] intValue]/255.0f) blue:([MaxColor[2] intValue]/255.0f) alpha:([MaxColor[3] intValue]/255.0f)];    }@end

0 0