Vignettes d'image ASP.NET

Question

J'essaie de générer des vignettes à partir de fichiers image stockés dans un dossier situé sous la racine du site Web. J'utilise actuellement les fonctionnalités intégrées dans .NET pour générer dynamiquement les vignettes, mais la qualité devient assez mauvaise et, depuis, c'est une boutique en ligne thats. un vrai problème, ma question est de savoir s’il existe de bons frameworks (open source?) qui peuvent m’aider à gérer la création et la création de vignettes d’images, ainsi qu’une aide éventuelle pour la compression de la taille des fichiers d’image lors du téléchargement?

J'ai regardé mais je n'ai encore rien trouvé?

Merci d'avance.

Answer 1

J'ai écrit du code que vous pourriez utiliser. S'il vous plaît ne le vendez pas;)

Ceci est le code:

/*
 *  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
    }
}

Voici comment vous pourriez l'utiliser:

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();

Le code que j'ai écrit peut réellement redimensionner vos images selon un pourcentage spécifique.