OpenCV (iOS)中的形態學變換(11)

一個蘿蔔壹個坑發表於2018-01-03

形態學的高階形態往往是建立在腐蝕和膨脹這兩個基本操作之上,關於腐蝕和膨脹請參考OpenCV中的腐蝕和膨脹(9)

使用OpenCV中函式morphologyEx進行形態學操作

(1)開運算 (Opening)

(2)閉運算 (Closing)

(3)形態梯度 (Morphological Gradient)

(4)頂帽 (Top Hat)

(5)黑帽(Black Hat)

開運算(Opening)

開運算是通過先對影象腐蝕再膨脹實現的

能夠排除小團塊的物體(假設物體背景明亮)

閉運算(Closing)

閉運算是通過先對影象膨脹後再腐蝕實現的

OpenCV (iOS)中的形態學變換(11)

能夠排除小型黑洞(黑色區域)

形態梯度(Morphological Gradient)

膨脹圖與腐蝕圖只差

OpenCV (iOS)中的形態學變換(11)

頂帽(Top Hat)

原影象與開運算結果的圖只差

OpenCV (iOS)中的形態學變換(11)

黑帽(Black Hat)

閉運算結果圖與原影象只差

函式morphologyEx引數介紹

void morphologyEx( InputArray src,// 預處理影象

                                 OutputArray dst,// 處理結果影象

                                int op,// 需要執行的形態學操作

                                InputArray kernel,                  

                                Point anchor = Point(-1,-1),

                                int iterations =1,

                                int borderType = BORDER_CONSTANT,

                               const Scalar& borderValue = morphologyDefaultBorderValue()

                                );

op 有六種形式 (2--6)

Opening:MORPH_OPEN: 2 // 開運算

Closing:MORPH_CLOSE: 3 // 閉運算

Gradient:MORPH_GRADIENT: 4 // 形態梯度

Top Hat:MORPH_TOPHAT: 5 // 頂帽

Black Hat:MORPH_BLACKHAT: 6 // 黑帽

程式碼

- (void)initMat {

self.img = [UIImage imageNamed:@"123.png"];

UIImageToMat(_img, m_src);

[self morphologyEx];

}

- (void)createImageView {

CGFloat h = self.view.frame.size.width * 2 / 3;

self.imgView1 = [[UIImageView alloc] initWithFrame:CGRectMake(0, 20, self.view.frame.size.width, h)];

[self.view addSubview:_imgView1];

_imgView1.backgroundColor = [UIColor lightGrayColor];

_imgView1.image = _img;

self.imgView2 = [[UIImageView alloc] initWithFrame:CGRectMake(0, CGRectGetMaxY(_imgView1.frame) + 5, self.view.frame.size.width, h)];

[self.view addSubview:_imgView2];

_imgView2.backgroundColor = [UIColor lightGrayColor];

_imgView2.image = _img;

}

- (void)createSlider {

NSArray *tempArr = @[@"Operator :", @"Element :", @"Kernel Size :"];

CGFloat w = self.view.frame.size.width - 100;

CGFloat y = self.view.frame.size.height - 50;

for (NSInteger i = 0; i < 3; i++) {

UISlider *slider = [[UISlider alloc] initWithFrame:CGRectMake(90,  y - 45 * i, w, 40)];

[self.view addSubview:slider];

[slider addTarget:self action:@selector(valueChanged:)

forControlEvents:UIControlEventValueChanged];

[self sliderMumValueWith:i slider:slider];

slider.tag = 1000 + i;

UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, y - 45 * i, 80, 40)];

label.textAlignment = NSTextAlignmentRight;

[self.view addSubview:label];

label.font = [UIFont systemFontOfSize:10];

label.text = tempArr[i];

}

}

- (void)sliderMumValueWith:(NSInteger)i slider:(UISlider *)slider {

switch (i) {

case 0: {

slider.continuous = YES; // NO makes it call only once you let go

slider.minimumValue = 2;

slider.maximumValue = 6;

} break;

case 1: {

slider.continuous = YES; // NO makes it call only once you let go

slider.minimumValue = 0;

slider.maximumValue = 2;

} break;

case 2: {

slider.continuous = YES; // NO makes it call only once you let go

slider.minimumValue = 0;

slider.maximumValue = 21;

} break;

}

}

- (void)morphologyEx {

// 由於 MORPH_X的取值範圍是: 2,3,4,5 和 6

Mat element = getStructuringElement(morph_elem, cv::Size(2 * morph_size + 1, 2 * morph_size + 1), cv::Point(morph_size, morph_size));

/// 執行指定形態學操作

morphologyEx(m_src, m_dst, morph_operator, element);

_imgView2.image = MatToUIImage(m_dst);//morph_operator

}


建立公共變數

Mat m_src, m_dst;

int morph_elem = 0;

int morph_size = 0;

int morph_operator = 0;

呼叫

[self initMat];

[self createSlider];

[self createImageView];

參考資料

OpenCV for iOS 學習筆記(十)—— 形態學變換

更多形態學變換

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