Increase and decrease colour contrast of an Image c#

Question

HI Guys  Thanks for your quick response for my previous posts ...I need your help again I am working with a web application in c#..I need to increase and decrease the color contrast of an Image using the scroll bar..please post the code as soon as possible

Balaji Essakki · Answer

no still i am getting the same error

Raaj Kumar · Answer

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

Balaji Essakki · Answer

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 { for (int y = 0; 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) 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(); } } }

Raaj Kumar · Answer

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

Balaji Essakki · Answer

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

Raaj Kumar · Answer

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

Balaji Essakki · Answer

but there is an error occurs while saving the bitmap to tofilename A generic error occurred in GDI+.

Raaj Kumar · Answer

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

Balaji Essakki · Answer

Thanks a lot Raaj...

Raaj Kumar · Answer

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