我的

QXLive/Tools/Category/UIImage+QX.h

@@ -31,7 +31,13 @@ typedef NS_ENUM(NSUInteger, GradientType) {
 + (UIImage *)qx_convertViewToImageWith:(UIView *)view;
 
 + (UIImage *)qx_gradientColorImageFromColors:(NSArray*)colors gradientType:(GradientType)gradientType imgSize:(CGSize)imgSize;
+/**
+ 传入一张图片将图片改为灰色
 
+ @param inputImage 传入图片
+ @return 生成的UIImage
+ */
++ (UIImage *)qx_convertImageToGrayWithCoreImage:(UIImage *)inputImage;
 /**
  根据颜色，生成UIImage对象
 

QXLive/Tools/Category/UIImage+QX.m

@@ -42,7 +42,24 @@
 
     return image;
 }
-
++ (UIImage *)qx_convertImageToGrayWithCoreImage:(UIImage *)inputImage {
+    CIImage *ciImage = [[CIImage alloc] initWithImage:inputImage];
+    
+    // 使用黑白滤镜
+    CIFilter *grayFilter = [CIFilter filterWithName:@"CIColorControls"];
+    [grayFilter setValue:ciImage forKey:kCIInputImageKey];
+    [grayFilter setValue:@(0.0) forKey:kCIInputSaturationKey]; // 饱和度设为0即为灰色
+    
+    CIImage *outputImage = [grayFilter valueForKey:kCIOutputImageKey];
+    
+    CIContext *context = [CIContext contextWithOptions:nil];
+    CGImageRef cgImage = [context createCGImage:outputImage fromRect:[outputImage extent]];
+    
+    UIImage *grayImage = [UIImage imageWithCGImage:cgImage];
+    CGImageRelease(cgImage);
+    
+    return grayImage;
+}
 + (UIImage *)qx_gradientColorImageFromColors:(NSArray *)colors gradientType:(GradientType)gradientType imgSize:(CGSize)imgSize {
     NSMutableArray *ar = [NSMutableArray array];
     for (UIColor *c in colors) {