[C#/WINFORM] Bitmap 클래스 : 바이-톤 필터(Bi-tonal Filter) 사용하기

TestProject.zip

다운로드

▶ BitmapHelper.cs

using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using System.Drawing.Drawing2D;

namespace TestProject
{
    /// <summary>
    /// 비트맵 헬퍼
    /// </summary>
    public static class BitmapHelper
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Method
        ////////////////////////////////////////////////////////////////////////////////////////// Static
        //////////////////////////////////////////////////////////////////////////////// Public

        #region 비트맵 구하기 - GetBitmap(sourceBitmap, targetWidth)

        /// <summary>
        /// 비트맵 구하기
        /// </summary>
        /// <param name="sourceBitmap">소스 비트맵</param>
        /// <param name="targetWidth">타겟 너비</param>
        /// <returns>비트맵</returns>
        public static Bitmap GetBitmap(Bitmap sourceBitmap, int targetWidth)
        {
            int maximumSide = sourceBitmap.Width > sourceBitmap.Height ? sourceBitmap.Width : sourceBitmap.Height;

            float ratio = (float)maximumSide / (float)targetWidth;

            Bitmap targetBitmap = (sourceBitmap.Width > sourceBitmap.Height ? new Bitmap(targetWidth, (int)(sourceBitmap.Height / ratio)) :
                                                                              new Bitmap((int)(sourceBitmap.Width / ratio), targetWidth));

            using(Graphics targetGraphics = Graphics.FromImage(targetBitmap))
            {
                targetGraphics.CompositingQuality = CompositingQuality.HighQuality;
                targetGraphics.InterpolationMode  = InterpolationMode.HighQualityBicubic;
                targetGraphics.PixelOffsetMode    = PixelOffsetMode.HighQuality;

                targetGraphics.DrawImage
                (
                    sourceBitmap,
                    new Rectangle(0, 0, targetBitmap.Width, targetBitmap.Height),
                    new Rectangle(0, 0, sourceBitmap.Width, sourceBitmap.Height),
                    GraphicsUnit.Pixel
                );

                targetGraphics.Flush();
            }

            return targetBitmap;
        }

        #endregion
        #region 바이-톤 필터 적용하기 - ApplyBitonalFilter(sourceBitmap, darkColor, lightColor, threshold)

        /// <summary>
        /// 바이-톤 필터 적용하기
        /// </summary>
        /// <param name="sourceBitmap">소스 비트맵</param>
        /// <param name="darkColor">어두운 색상</param>
        /// <param name="lightColor">밝은 색상</param>
        /// <param name="threshold">임계치</param>
        /// <returns>비트맵</returns>
        public static Bitmap ApplyBitonalFilter(Bitmap sourceBitmap, Color darkColor, Color lightColor, int threshold)
        {
            BitmapData sourceBitmapData = sourceBitmap.LockBits
            (
                new Rectangle(0, 0, sourceBitmap.Width, sourceBitmap.Height),
                ImageLockMode.ReadOnly,
                PixelFormat.Format32bppArgb
            );

            byte[] targetByteArray = new byte[sourceBitmapData.Stride * sourceBitmapData.Height];

            Marshal.Copy(sourceBitmapData.Scan0, targetByteArray, 0, targetByteArray.Length);

            sourceBitmap.UnlockBits(sourceBitmapData);

            for(int i = 0; i + 4 < targetByteArray.Length; i += 4)
            {
                if (targetByteArray[i] + targetByteArray[i + 1] + targetByteArray[i + 2] <= threshold)
                {
                    targetByteArray[i    ] = darkColor.B;
                    targetByteArray[i + 1] = darkColor.G;
                    targetByteArray[i + 2] = darkColor.R;
                }
                else
                {
                    targetByteArray[i    ] = lightColor.B;
                    targetByteArray[i + 1] = lightColor.G;
                    targetByteArray[i + 2] = lightColor.R;
                }
            }

            Bitmap targetBitmap = new Bitmap(sourceBitmap.Width, sourceBitmap.Height);

            BitmapData targetBitmapData = targetBitmap.LockBits
            (
                new Rectangle(0, 0, targetBitmap.Width, targetBitmap.Height),
                ImageLockMode.WriteOnly,
                PixelFormat.Format32bppArgb
            );

            Marshal.Copy(targetByteArray, 0, targetBitmapData.Scan0, targetByteArray.Length);

            targetBitmap.UnlockBits(targetBitmapData);

            return targetBitmap;
        }

        #endregion
    }
}

 

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▶ MainForm.cs

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Windows.Forms;

namespace TestProject
{
    /// <summary>
    /// 메인 폼
    /// </summary>
    public partial class MainForm : Form
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Field
        ////////////////////////////////////////////////////////////////////////////////////////// Private

        #region Field

        /// <summary>
        /// 소스 비트맵
        /// </summary>
        private Bitmap sourceBitmap = null;

        /// <summary>
        /// 미리보기 비트맵
        /// </summary>
        private Bitmap previewBitmap = null;

        /// <summary>
        /// 타겟 비트맵
        /// </summary>
        private Bitmap targetBitmap = null;

        #endregion

        //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor
        ////////////////////////////////////////////////////////////////////////////////////////// Public

        #region 생성자 - MainForm()

        /// <summary>
        /// 생성자
        /// </summary>
        public MainForm()
        {
            InitializeComponent();

            this.darkColorPanel.Click           += colorPanel_Click;
            this.lightColorPanel.Click          += colorPanel_Click;
            this.thresholdTrackBar.ValueChanged += thresholdTrackBar_ValueChanged;
            this.loadImageButton.Click          += localImageButton_Click;
            this.saveImageButton.Click          += saveImageButton_Click;
        }

        #endregion

        //////////////////////////////////////////////////////////////////////////////////////////////////// Method
        ////////////////////////////////////////////////////////////////////////////////////////// Private
        //////////////////////////////////////////////////////////////////////////////// Event

        #region 색상 패널 클릭시 처리하기 - colorPanel_Click(sender, e)

        /// <summary>
        /// 색상 패널 클릭시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void colorPanel_Click(object sender, EventArgs e)
        {
            if(sender is Panel)
            {
                Panel panel = (Panel)sender;

                ColorDialog colorDialog = new ColorDialog();

                colorDialog.AllowFullOpen = true;
                colorDialog.Color         = panel.BackColor;
                colorDialog.FullOpen      = true;

                if(colorDialog.ShowDialog() == DialogResult.OK)
                {
                    panel.BackColor = colorDialog.Color;

                    ApplyFilter(true);
                }
            }
        }

        #endregion
        #region 임계치 트랙바 값 변경시 처리하기 - thresholdTrackBar_ValueChanged(sender, e)

        /// <summary>
        /// 임계치 트랙바 값 변경시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void thresholdTrackBar_ValueChanged(object sender, EventArgs e)
        {
            this.thresholdValueLabel.Text = this.thresholdTrackBar.Value.ToString();

            ApplyFilter(true);
        }

        #endregion
        #region 이미지 로드 버튼 클릭시 처리하기 - localImageButton_Click(sender, e)

        /// <summary>
        /// 이미지 로드 버튼 클릭시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void localImageButton_Click(object sender, EventArgs e)
        {
            OpenFileDialog openFileDialog = new OpenFileDialog();

            openFileDialog.Title  = "이미지 파일 로드";
            openFileDialog.Filter = "PNG 이미지(*.png)|*.png|JPEG 이미지(*.jpg)|*.jpg|비트맵 이미지(*.bmp)|*.bmp";

            if(openFileDialog.ShowDialog() == DialogResult.OK)
            {
                StreamReader streamReader = new StreamReader(openFileDialog.FileName);

                this.sourceBitmap = Bitmap.FromStream(streamReader.BaseStream) as Bitmap;

                streamReader.Close();

                this.previewBitmap = BitmapHelper.GetBitmap(this.sourceBitmap, this.pictureBox.Width);

                this.pictureBox.Image = this.previewBitmap;

                ApplyFilter(true);
            }
        }

        #endregion
        #region 이미지 저장 버튼 클릭시 처리하기 - saveImageButton_Click(sender, e)

        /// <summary>
        /// 이미지 저장 버튼 클릭시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void saveImageButton_Click(object sender, EventArgs e)
        {
            ApplyFilter(false);

            if(this.targetBitmap != null)
            {
                SaveFileDialog saveFileDialog = new SaveFileDialog();

                saveFileDialog.Title  = "이미지 파일 저장";
                saveFileDialog.Filter = "PNG 이미지(*.png)|*.png|JPEG 이미지(*.jpg)|*.jpg|비트맵 이미지(*.bmp)|*.bmp";

                if(saveFileDialog.ShowDialog() == DialogResult.OK)
                {
                    string fileExtension = Path.GetExtension(saveFileDialog.FileName).ToUpper();

                    ImageFormat imageFormat = ImageFormat.Png;

                    if(fileExtension == "BMP")
                    {
                        imageFormat = ImageFormat.Bmp;
                    }
                    else if(fileExtension == "JPG")
                    {
                        imageFormat = ImageFormat.Jpeg;
                    }

                    StreamWriter streamWriter = new StreamWriter(saveFileDialog.FileName, false);

                    this.targetBitmap.Save(streamWriter.BaseStream, imageFormat);

                    streamWriter.Flush();
                    streamWriter.Close();

                    this.targetBitmap = null;
                }
            }
        }

        #endregion

        //////////////////////////////////////////////////////////////////////////////// Function

        #region 필터 적용하기 - ApplyFilter(preview)

        /// <summary>
        /// 필터 적용하기
        /// </summary>
        /// <param name="preview">미리보기 여부</param>
        private void ApplyFilter(bool preview)
        {
            if(this.previewBitmap == null)
            {
                return;
            }

            if(preview == true)
            {
                this.pictureBox.Image = BitmapHelper.ApplyBitonalFilter
                (
                    this.previewBitmap,
                    this.darkColorPanel.BackColor,
                    this.lightColorPanel.BackColor,
                    this.thresholdTrackBar.Value
                );
            }
            else
            {
                this.targetBitmap = BitmapHelper.ApplyBitonalFilter
                (
                    this.sourceBitmap,
                    this.darkColorPanel.BackColor,
                    this.lightColorPanel.BackColor,
                    this.thresholdTrackBar.Value
                );
            }
        }

        #endregion
    }
}