how can I Resize the thumbnail image, and give it a specific dimensions

rmhanna

THUMBNAIL IMAGE: I AM READING THE BINARY FORMAT OF THE IMAGE FROM DATABASE, TO CONVERT IT INTO THUMBNAIL PICTURE, BUT HOW CAN I REDUCE THE SIZE? fOR INSTANCE IF IMAGE SIZE IS 20K CAN IT BE 10 K BY REDUCING ITS BYTE ARRAY? I AM DIVIDING ITS BYTEARRAY/2 TO DECREASE ITS SIZE. But I RECEIVING AN ERROR ( ERROR: (69): Operator '/' cannot be applied to operands of type 'byte[]' and 'int'). ALSO, I GAVE IT WIDTH=300 AND HEIGHT= 300 BUT ITS DEFAULT SIZE IS DISPLAYED ON THE PAGE AND NOTHING HAS BEEN CHANGED my code smaple: byte [] byteArray = (byte[]) ReaderObj["IMAGE_DATA"]; System.IO.MemoryStream mstream = new System.IO.MemoryStream((Int32.Parse(byteArray/2)),0,byteArray.Length); System.Drawing.Image thumbnailImage =dbImage.GetThumbnailImage(300,300,null, new System.IntPtr()); thumbnailImage.Save(mstream, System.Drawing.Imaging.ImageFormat.Gif);.... TECH: I AM USING C#.NET

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rmhanna21y ago
Hello, I've tried what you told me, but unfortunately nothing has been changed. the size is still as it was before. The dimensions are also as they were...no error in my code , the image can be displayed as when it was saved by default in db so plz give ur suggestion: The modified code: byte [] byteArray = (byte[]) ReaderObj["FILE_DATA"]; Response.ContentType=ReaderObj["CONTENT_TYPE"].ToString(); Response.BinaryWrite(byteArray); //To draw a thumbnail we are going to create a System.Drawing. System.IO.MemoryStream mstream = new System.IO.MemoryStream(byteArray,0,byteArray.Length); System.Drawing.Image dbImage = System.Drawing.Image.FromStream( new System.IO.MemoryStream(byteArray)); int imght=((dbImage.Height)*3); //calculate the amount to shink the height and width thumbnailWidth =Convert.ToInt32(Math.Round((Convert.ToDouble(150)/imght) * dbImage.Width)); // create the thumbnail image //System.Drawing.Image thumbnailImage =dbImage.GetThumbnailImage(thumbnailWidth,300,new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), new System.IntPtr()); System.Drawing.Image thumbnailImage =dbImage.GetThumbnailImage(thumbnailWidth,300,new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback),IntPtr.Zero); thumbnailImage.RotateFlip(RotateFlipType.Rotate180FlipNone); szContentType=ReaderObj["CONTENT_TYPE"].ToString(); //detecting image format (gif,jpeg,bmp,png) if(szContentType=="image/gif") thumbnailImage.Save(mstream, System.Drawing.Imaging.ImageFormat.Gif); else if(szContentType=="image/JPEG") thumbnailImage.Save(mstream, System.Drawing.Imaging.ImageFormat.JPEG); else if(szContentType=="image/bmp") thumbnailImage.Save(mstream, System.Drawing.Imaging.ImageFormat.Gif); else if(szContentType=="image/png") thumbnailImage.Save(mstream, System.Drawing.Imaging.ImageFormat.Gif); Byte[] thumbnailByteArray = new Byte[mstream.Length]; mstream.Position = 0; mstream.Read(thumbnailByteArray, 0, Convert.ToInt32(mstream.Length)); Response.ContentType=ReaderObj["CONTENT_TYPE"].ToString(); if(ReaderObj.Read()==true) { Response.BinaryWrite(thumbnailByteArray); } Response.AddHeader("Content-Disposition","filename=" + szFileName); Con.Close();
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mibuyt21y ago
Hi, I think the 3rd parameter of GetThumbnailImage should be this: new Image.GetThumbnailImageAbort(ThumbnailCallback) // ThumbnailCallback - just create a bool function and return true and the 4th parameter: IntPtr.Zero Try this: But hmm... is there a problem of your code, or are you asking a solution to reduce the size... Seriously, if you have a bmp file and you want to change it to gif... it will actually increase the size... give it a try... print screen your desktop and paste into mspaint. Then try to save it to gif instead of jpeg. There is a lot of differences in terms if file sizes. Hope it helps. Cheers.
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