[C#/WINFORM] Image 클래스 : 이미지 크기 조정하기

■ Image 클래스에서 이미지 크기를 조정하는 방법을 보여준다.

▶ Image 클래스 : 이미지 크기 조정하기 예제 (C#)


Image sourceImage = Image.FromFile("c:\\source.jpg");

Image targetImage = ResizeImage(sourceImage, this.pictureBox.Size, Color.Blue);

Image sourceImage = Image.FromFile("c:\\source.jpg");

Image targetImage = ResizeImage(sourceImage, this.pictureBox.Size, Color.Blue);

※ pictureBox는 System.Windows.Forms.PictureBox 타입이다.

▶ Image 클래스 : 이미지 크기 조정하기 (C#)


using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;

#region 이미지 크기 조정하기 - ResizeImage(sourceImage, targetSize, backgroundColor, isImageCenterAligned)

/// <summary>
/// 이미지 크기 조정하기
/// </summary>
/// <param name="sourceImage">소스 이미지</param>
/// <param name="targetSize">타겟 크기</param>
/// <param name="backgroundColor">배경 색상</param>
/// <param name="isImageCenterAligned">이미지 가운데 정렬 여부</param>
/// <returns>이미지</returns>
public static Image ResizeImage(Image sourceImage, Size targetSize, Color backgroundColor, bool isImageCenterAligned = true)
{
    if(sourceImage == null || targetSize == Size.Empty)
    {
        return null;
    }

    int sourceWidth  = sourceImage.Size.Width;
    int sourceHeight = sourceImage.Size.Height;
    int targetWidth  = targetSize.Width;
    int targetHeight = targetSize.Height;

    Image targetImage = new Bitmap(targetWidth, targetHeight);

    Graphics targetGraphics = Graphics.FromImage(targetImage);

    targetGraphics.InterpolationMode  = InterpolationMode.HighQualityBicubic;
    targetGraphics.SmoothingMode      = SmoothingMode.HighQuality;
    targetGraphics.PixelOffsetMode    = PixelOffsetMode.HighQuality;
    targetGraphics.CompositingQuality = CompositingQuality.HighQuality;

    double ratioX = (double)targetWidth  / (double)sourceWidth;
    double ratioY = (double)targetHeight / (double)sourceHeight;
    double ratio  = ratioX < ratioY ? ratioX : ratioY;

    int newHeight = Convert.ToInt32(sourceHeight * ratio);
    int newWidth  = Convert.ToInt32(sourceWidth  * ratio);

    int positionX = Convert.ToInt32((targetWidth  - (sourceImage.Width  * ratio)) / 2);
    int positionY = Convert.ToInt32((targetHeight - (sourceImage.Height * ratio)) / 2);

    if(!isImageCenterAligned)
    {
        positionX = 0;
        positionY = 0;
    }

    targetGraphics.Clear(backgroundColor);

    targetGraphics.DrawImage(sourceImage, positionX, positionY, newWidth, newHeight);

    ImageCodecInfo[] imageCodecInfoArray = ImageCodecInfo.GetImageEncoders();

    EncoderParameters encoderParameters = new EncoderParameters(1);

    encoderParameters.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L);

    Stream stream = new MemoryStream();

    targetImage.Save(stream, imageCodecInfoArray[1], encoderParameters);

    return Image.FromStream(stream);
}

using System;

using System.Drawing;

using System.Drawing.Drawing2D;

using System.Drawing.Imaging;

using System.IO;

#region 이미지 크기 조정하기 - ResizeImage(sourceImage, targetSize, backgroundColor, isImageCenterAligned)

/// <summary>

/// 이미지 크기 조정하기

/// </summary>

/// <param name="sourceImage">소스 이미지</param>

/// <param name="targetSize">타겟 크기</param>

/// <param name="backgroundColor">배경 색상</param>

/// <param name="isImageCenterAligned">이미지 가운데 정렬 여부</param>

/// <returns>이미지</returns>

public static Image ResizeImage(Image sourceImage, Size targetSize, Color backgroundColor, bool isImageCenterAligned = true)

{

if(sourceImage == null || targetSize == Size.Empty)

{

return null;

}

int sourceWidth = sourceImage.Size.Width;

int sourceHeight = sourceImage.Size.Height;

int targetWidth = targetSize.Width;

int targetHeight = targetSize.Height;

Image targetImage = new Bitmap(targetWidth, targetHeight);

Graphics targetGraphics = Graphics.FromImage(targetImage);

targetGraphics.InterpolationMode = InterpolationMode.HighQualityBicubic;

targetGraphics.SmoothingMode = SmoothingMode.HighQuality;

targetGraphics.PixelOffsetMode = PixelOffsetMode.HighQuality;

targetGraphics.CompositingQuality = CompositingQuality.HighQuality;

double ratioX = (double)targetWidth / (double)sourceWidth;

double ratioY = (double)targetHeight / (double)sourceHeight;

double ratio = ratioX < ratioY ? ratioX : ratioY;

int newHeight = Convert.ToInt32(sourceHeight * ratio);

int newWidth = Convert.ToInt32(sourceWidth * ratio);

int positionX = Convert.ToInt32((targetWidth - (sourceImage.Width * ratio)) / 2);

int positionY = Convert.ToInt32((targetHeight - (sourceImage.Height * ratio)) / 2);

if(!isImageCenterAligned)

{

positionX = 0;

positionY = 0;

}

targetGraphics.Clear(backgroundColor);

targetGraphics.DrawImage(sourceImage, positionX, positionY, newWidth, newHeight);

ImageCodecInfo[] imageCodecInfoArray = ImageCodecInfo.GetImageEncoders();

EncoderParameters encoderParameters = new EncoderParameters(1);

encoderParameters.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L);

Stream stream = new MemoryStream();

targetImage.Save(stream, imageCodecInfoArray[1], encoderParameters);

return Image.FromStream(stream);

}