Increase and decrease colour contrast of an Image c#

no still i am getting the same error

Hi,


It seems there is no problem in code. Could you please check the permission of the folder for read/write operation if you have hosted in IIS. Otherwise Right-Click on MembershipImages folder and uncheck the readonly property. Since if you dont have permission it will throw this error.

Regards,
raaj

Although i was using the same filename its not working

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;

public partial class slider : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Image1.ImageUrl = "MembershipImages/Sample.jpg";
    }
    protected void txtBrightness_TextChanged(object sender, EventArgs e)
    {
        string filename = Server.MapPath("MembershipImages/brightImage.jpg");
        AdjustBrightness(filename, Convert.ToInt16(txtBrightness.Text));
    }

    protected void txtContrast_TextChanged(object sender, EventArgs e)
    {
        string filename = Server.MapPath("MembershipImages/brightImage.jpg");
        AdjustContrast(filename, Convert.ToSByte(txtContrast.Text));
    }

    #region Core
    public void AdjustBrightness(string fileName, int Value)
    {
        Bitmap oBitmap = default(Bitmap);

        oBitmap = new Bitmap(fileName);
        Graphics oGraphic = default(Graphics);
        Bitmap bmpNew = new Bitmap(oBitmap.Width, oBitmap.Height);
        oGraphic = Graphics.FromImage(bmpNew);

        float FinalValue = (float)Value / 255.0f;
        float[][] FloatColorMatrix ={
                    new float[] {1, 0, 0, 0, 0},
                    new float[] {0, 1, 0, 0, 0},
                    new float[] {0, 0, 1, 0, 0},
                    new float[] {0, 0, 0, 1, 0},
                    new float[] {FinalValue, FinalValue, FinalValue, 1, 1}
                };

        ColorMatrix NewColorMatrix = new ColorMatrix(FloatColorMatrix);
        ImageAttributes Attributes = new ImageAttributes();
        Attributes.SetColorMatrix(NewColorMatrix);
        oGraphic.DrawImage(oBitmap, new Rectangle(0, 0, bmpNew.Width, bmpNew.Height), 0, 0, oBitmap.Width, oBitmap.Height, GraphicsUnit.Pixel, Attributes);

        oBitmap.Dispose();
        oBitmap = bmpNew;
        oGraphic.Dispose();

        oBitmap.Save(fileName, ImageFormat.Jpeg);
        oBitmap.Dispose();
    }

    public void AdjustContrast(string fileName, float Value)
    {
        Bitmap oBitmap = default(Bitmap);

        oBitmap = new Bitmap(fileName);
        Graphics oGraphic = default(Graphics);
        Bitmap bmpNew = new Bitmap(oBitmap.Width, oBitmap.Height);
        oGraphic = Graphics.FromImage(bmpNew);

        float FinalValue = (float)Value / 255.0f;
        float[][] FloatColorMatrix ={
                    new float[] {Value, 0f, 0f, 0f, 0f},
                    new float[] {0f, Value, 0f, 0f, 0f},
                    new float[] {0f, 0f, Value, 0f, 0},
                    new float[] {0f, 0f, 0f, 1f, 0f},
                    new float[] {0.001f, 0.001f, 0.001f, 0f, 1f}
                };

        ColorMatrix NewColorMatrix = new ColorMatrix(FloatColorMatrix);
        ImageAttributes Attributes = new ImageAttributes();
        Attributes.SetColorMatrix(NewColorMatrix);
        oGraphic.DrawImage(oBitmap, new Rectangle(0, 0, bmpNew.Width, bmpNew.Height), 0, 0, oBitmap.Width, oBitmap.Height, GraphicsUnit.Pixel, Attributes);

        oBitmap.Dispose();
        oBitmap = bmpNew;
        oGraphic.Dispose();

        oBitmap.Save(fileName, ImageFormat.Jpeg);
        oBitmap.Dispose();
    }
    public void AdjustContrast(Bitmap Image, float Value, string tofileName)
    {
        Value = (100.0f + Value) / 100.0f;
        Value *= Value;
        System.Drawing.Bitmap TempBitmap = Image;
        System.Drawing.Bitmap NewBitmap = new System.Drawing.Bitmap(TempBitmap.Width, TempBitmap.Height);
        System.Drawing.Graphics NewGraphics = System.Drawing.Graphics.FromImage(NewBitmap);
        NewGraphics.DrawImage(TempBitmap, new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), System.Drawing.GraphicsUnit.Pixel);
        NewGraphics.Dispose();

        for (int x = 0; x < NewBitmap.Width; ++x)
        {
            for (int y = 0; y < NewBitmap.Height; ++y)
            {
                Color Pixel = NewBitmap.GetPixel(x, y);
                float Red = Pixel.R / 255.0f;
                float Green = Pixel.G / 255.0f;
                float Blue = Pixel.B / 255.0f;
                Red = (((Red - 0.5f) * Value) + 0.5f) * 255.0f;
                Green = (((Green - 0.5f) * Value) + 0.5f) * 255.0f;
                Blue = (((Blue - 0.5f) * Value) + 0.5f) * 255.0f;
                NewBitmap.SetPixel(x, y, Color.FromArgb(Clamp((int)Red, 255, 0), Clamp((int)Green, 255, 0), Clamp((int)Blue, 255, 0)));
            }
        }

        FileInfo imgFile = new FileInfo(tofileName);
        NewBitmap.Save(imgFile.OpenWrite(), System.Drawing.Imaging.ImageFormat.Jpeg);
        imgFile = null;
        NewBitmap.Dispose();

    }


    public T Clamp(T value, T max, T min) where T : System.IComparable
    {
        T result = value;
        if (value.CompareTo(max) > 0)
            result = max;
        if (value.CompareTo(min) < 0)
            result = min;
        return result;
    }
    #endregion

    private void ReadWriteStream(string filePath)
    {
        byte[] buffer;
        FileStream fStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
        try
        {
            int length = (int)fStream.Length;
            buffer = new byte[length];
            int count, sum = 0;
            while ((count = fStream.Read(buffer, sum, length - sum)) > 0)
            {
                sum += count;
            }

        }
        catch (Exception ex)
        {
            Response.Write(ex.Message);
        }
        finally
        {
            fStream.Close();
            fStream.Dispose();
        }

    }
}

Hi,
For me it is working. Could you please post the code so that I can tell you what exaclty to be done?
Regards,
Raaj

still i am getting the same error...If i give the file name which is already in the folder means same error occurs..if i give a new file name means its showing invalid parameter

Hi,

 Check this application. It is because I didn't handle the object disposal properly. Now it is done. Here I have overwritten the existing image with processed image. For your convenience you can store it in separate file.

Regards,
raaj

but there is an error occurs while saving the bitmap to tofilename


A generic error occurred in GDI+.

If it helps could you please mark it as an answer?

Thanks a lot Raaj...

Hi,


  You can refer the similar post which I have answered.

http://www.c-sharpcorner.com/Forums/ShowMessages.aspx?ThreadID=79909

But there is no scrollbar instead Ajax SliderControl is used. However you can make use of the logic behind that.


Regards,
raaj