图像缩略图ASP.NET

Question

我想，我目前使用从网站根目录下存放的文件夹中的图像文件的缩略图内置在.NET capebilites动态生成缩略图，但质量变得相当糟糕，并因为它的一个网上商店这就是给genererate一个现实的问题，我的问题是，如果有什么好的（开源？）的框架，可以帮助我hanlde上传过程中的图像创建缩略图和rezise和可能的帮助与图像文件大小压缩？

我看了，但还没有发现任何没有？

预先感谢。

Answer 1

我已经写了一些代码，你可以使用。请不要卖掉它;）

这是代码：

/*
 *  Software Developed by Filip Ekberg ( Filip@SmartIT.se )
 * 
 *  For Questions regarding this software, please send me an E-mail
 * 
 */

#region Usings
using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
#endregion

namespace ImageResizer
{
    class ImageProcessor
    {
        #region Members
        private int m_imgWidht,
                    m_imgHeight,
                    m_oImgWidht,
                    m_oImgHeight;

        private float m_vertRes,
                      m_horiRes;

        private double m_size = 0.25;

        private Bitmap m_Bitmap;
        private Graphics m_Graphics;
        private Image m_currentImage;

        private PixelFormat m_pxlFormat = PixelFormat.Format32bppRgb;
        private InterpolationMode m_interpolationMode = InterpolationMode.HighQualityBilinear;
        private CompositingQuality m_compositingQuality = CompositingQuality.HighQuality;
        private SmoothingMode m_smoothingMode = SmoothingMode.None;
        #endregion

        #region Access Methods

        public int ImageWidth 
        {
            get { return m_imgWidht; }
        }
        public int ImageHeight 
       {
            get { return m_imgHeight; }
        }
        public float VerticalResolution
        {
            get { return m_vertRes; }
            set { m_vertRes = value; }
        }
        public float HorizonalResolution
        {
            get { return m_horiRes; }
            set { m_horiRes = value; }
        }

        /// <summary>
        /// Use ImageSize struct for setting this.
        /// </summary>
        public double Size
        {
            get { return m_size; }
            set { m_size = value; }
        }
        public Image ProcessImage
        {
            get { return m_currentImage; }
            set { m_currentImage = value; }
        }
        public PixelFormat ImagePixelFormat 
        {
            get { return m_pxlFormat; }
            set { m_pxlFormat = value; }
        }
        public InterpolationMode ImageInterpolationMode
        {
            get { return m_interpolationMode; }
            set { m_interpolationMode = value; }
        }
        public CompositingQuality ImageCompositingQuality
        {
            get { return m_compositingQuality; }
            set { m_compositingQuality = value; }
        }
        public SmoothingMode ImageSmoothingMode
        {
            get { return m_smoothingMode; }
            set { m_smoothingMode = value; }
        }

        #endregion

        #region Process Image
        public Bitmap BeginProcess()
        {
            if ( m_currentImage == null )
                return null;

            m_oImgWidht = m_currentImage.Width;
            m_oImgHeight = m_currentImage.Height;

            m_vertRes = m_currentImage.VerticalResolution;
            m_horiRes = m_currentImage.HorizontalResolution;

            m_imgWidht = (int)(m_oImgWidht * (double)m_size);
            m_imgHeight = (int)(m_oImgHeight * (double)m_size);


            m_Bitmap = new Bitmap(m_imgWidht, m_imgHeight, m_pxlFormat);

            m_Bitmap.SetResolution(m_vertRes, m_horiRes);

            m_Graphics = Graphics.FromImage(m_Bitmap);

            m_Graphics.InterpolationMode = m_interpolationMode;

            m_Graphics.CompositingQuality = m_compositingQuality;

            m_Graphics.SmoothingMode = m_smoothingMode;

            // m_Graphics.DrawImage(m_currentImage, new Rectangle(0, 0, m_imgWidht, m_imgHeight), new Rectangle(0, 0, m_oImgWidht, m_oImgHeight), GraphicsUnit.Pixel);

            Rectangle rectDestination = new Rectangle(0, 0, m_imgWidht, m_imgHeight);
           // m_Graphics.DrawImage(m_currentImage,
           //     new Rectangle(-1, -1, m_oImgWidht + 2, m_oImgHeight + 2),
            //    new Rectangle(m_oImgWidht, m_oImgHeight, m_imgWidht, m_oImgHeight),
            //    GraphicsUnit.Pixel);
            ImageAttributes ia = new ImageAttributes();
            ia.SetWrapMode(WrapMode.TileFlipXY);
            m_Graphics.DrawImage(m_currentImage, rectDestination, 0, 0, m_oImgWidht, m_oImgHeight, GraphicsUnit.Pixel, ia); 

            // m_Graphics.Dispose();

            return m_Bitmap;
        }
        #endregion
    }
}

这是如何使用它：

private ImageProcessor m_processor = new ImageProcessor();


m_currentImage = new Bitmap(currentFile.FullName);

                // Display a Thumbnail of it
                pictureBox1.Image = m_currentImage.GetThumbnailImage(pictureBox1.Width, pictureBox1.Height, null, IntPtr.Zero);

                // Update the Label with Filename and what file is currently processed
                delegate_lblControl(currentFile.Name + "\n" + m_currentProcessedImage + " / " + m_fileList.Length);

                // Increase the value on the ProcessBar
                delegate_imageProcessValue(1);

                // Process the Image
                m_processor.ProcessImage = m_currentImage;

                m_processor.Size = m_size;

                m_finalProcessedImage = m_processor.BeginProcess();

                ImageCodecInfo jgpEncoder = GetEncoder(ImageFormat.Jpeg);
                System.Drawing.Imaging.Encoder myEncoder =
                    System.Drawing.Imaging.Encoder.Quality;

                EncoderParameters myEncoderParameters = new EncoderParameters(1);
                EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, m_jpegQuality);
                myEncoderParameters.Param[0] = myEncoderParameter;


                // Save the Image to the Output folder
                m_finalProcessedImage.Save(fldOutput.SelectedPath + "\\" + currentFile.Name, jgpEncoder, myEncoderParameters);

                // Dispose the Images
                m_finalProcessedImage.Dispose();

                m_currentImage.Dispose();

我所实际写入能做的代码是调整图片到一个特定的百分比。