Day 114 : 이미지

1. 비트맵의 기본

: Bitmap 클래스는 캔버스에 이미지 파일을 보여주는 데 사용

 

- 이미지를 화면 중앙에 출력하는 Java 코드

package com.cookandroid.project9_2;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyGraphicView(this));
    }

    private static class MyGraphicView extends View {
        public MyGraphicView(Context context) {
            super(context);
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            Bitmap picture = BitmapFactory.decodeResource(getResources(), R.drawable.img05);
            //화면 중앙에 출력
            int picX = (this.getWidth() - picture.getWidth()) / 2;
            int picY = (this.getHeight() - picture.getHeight()) / 2;
            canvas.drawBitmap(picture, picX, picY, null);
            picture.recycle();
        }
    }
}

 

2. 이미지의 기하학적 변환

: 이미지 이동, 확대, 축소, 회전, 기울이기 등

 

- 기하학적 변환의 Java 코드

package com.cookandroid.project9_2;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyGraphicView(this));
    }

    private static class MyGraphicView extends View {
        public MyGraphicView(Context context) {
            super(context);
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            Bitmap picture = BitmapFactory.decodeResource(getResources(), R.drawable.img05);

            int cenX = this.getWidth() / 2;
            int cenY = this.getHeight() / 2;
            int picX = (this.getWidth() - picture.getWidth()) / 2;
            int picY = (this.getWidth() - picture.getHeight()) / 2;
    
            //45도 회전
            canvas.rotate(45, cenX, cenY);
            canvas.drawBitmap(picture, picX, picY, null);

            //이동
            canvas.translate(-150, 200);
            canvas.drawBitmap(picture, picX, picY, null);

            //2배 확대
            canvas.scale(2, 2, cenX, cenY);
            canvas.drawBitmap(picture, picX, picY, null);

            //0.3만큼 기울임
            canvas.skew(0.3f, 0.3f);
            canvas.drawBitmap(picture, picX, picY, null);

            picture.recycle();
        }
    }
}

 

3. 이미지 활용

- 블러링 : 이미지를 뿌옇게 만듦 - BlurMaskFilter 클래스 사용

package com.cookandroid.project9_2;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyGraphicView(this));
    }

    private static class MyGraphicView extends View {
        public MyGraphicView(Context context) {
            super(context);
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            Bitmap picture = BitmapFactory.decodeResource(getResources(), R.drawable.img05);

            int picX = (this.getWidth() - picture.getWidth()) / 2;
            int picY = (this.getHeight() - picture.getHeight()) / 2;
    
            Paint paint = new Paint();
            BlurMaskFilter bMask;

            //하나씩 실행
            bMask = new BlurMaskFilter(30, BlurMaskFilter.Blur.NORMAL);
            paint.setMaskFilter(bMask);
            canvas.drawBitmap(picture, picX, picY, paint);
            picture.recycle();

            bMask = new BlurMaskFilter(30, BlurMaskFilter.Blur.INNER);
            paint.setMaskFilter(bMask);
            canvas.drawBitmap(picture, picX, picY, paint);
            picture.recycle();

            bMask = new BlurMaskFilter(30, BlurMaskFilter.Blur.OUTER);
            paint.setMaskFilter(bMask);
            canvas.drawBitmap(picture, picX, picY, paint);
            picture.recycle();

            bMask = new BlurMaskFilter(30, BlurMaskFilter.Blur.SOLID);
            paint.setMaskFilter(bMask);
            canvas.drawBitmap(picture, picX, picY, paint);
            picture.recycle();
        }
    }
}

 

- 앰보싱 : 이미지가 볼록하게 튀어나와 보이는 효과를 냄 - EmbossMaskFilter 클래스 사용

package com.cookandroid.project9_2;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.EmbossMaskFilter;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyGraphicView(this));
    }

    private static class MyGraphicView extends View {
        public MyGraphicView(Context context) {
            super(context);
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            Bitmap picture = BitmapFactory.decodeResource(getResources(), R.drawable.img05);

            int cenX = this.getWidth() / 2;
            int cenY = this.getHeight() / 2;
    
            Paint paint = new Paint();
            paint.setColor(Color.GRAY);
            EmbossMaskFilter eMask;

            //빛 방향 변경
            eMask = new EmbossMaskFilter(new float[] {3,3,3}, 0.5f, 5, 10);
            paint.setMaskFilter(eMask);
            canvas.drawCircle(cenX, cenY, 150, paint);
        }
    }
}

 

- 컬러매트릭스 : 색상이나 밝기를 조절하기 위해 사용 - ColorMatrix, ColorMatrixColorFilter 클래스 사용

package com.cookandroid.project9_2;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.EmbossMaskFilter;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyGraphicView(this));
    }

    private static class MyGraphicView extends View {
        public MyGraphicView(Context context) {
            super(context);
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            Bitmap picture = BitmapFactory.decodeResource(getResources(), R.drawable.img05);

            int picX = (this.getWidth() - picture.getWidth()) / 2;
            int picY = (this.getHeight() - picture.getHeight()) / 2;
    
            Paint paint = new Paint();
            float[] array = {2,0,0,0,-25,
                            0,2,0,0,-25,
                            0,0,2,0,-25,
                            0,0,0,1,0};
            ColorMatrix cm = new ColorMatrix(array);
            paint.setColorFilter(new ColorMatrixColorFilter(cm));
            canvas.drawBitmap(picture, picX, picY, paint);
            picture.recycle();
        }
    }
}