Rendering Access Embedded OLE images into SQL back into JPEG images - AppGeo/GPV GitHub Wiki

We had a existing database of BLOB images in SQL for Sewer Cards. These were unformuately were inputted using TIFFs and the embedded OLE object method from Microsoft Access. As a result it was a two step process to render them for the web as JPEG. It only requires two files: ScanViewImage.aspx ScanViewImage.aspx.cs

The configurable pieces used are in ScanViewImage.aspx.cs:

string sqlText = "select im.ImageFile from stc.tblAddresses_Images im where im.ImageID = " + ImageId;

string connString = "Provider=SQLOLEDB.1;Password=password;Persist Security Info=True;User ID=username;Initial Catalog=Carddatabase;Data Source=sqlserver";

Code for ScanViewImage.aspx:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ScanViewImage.aspx.cs" Inherits="ViewImage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title></title> </head> <body> <form id="form1" runat="server"> <div>

``</div>``
``</form>``

</body> </html>

Code for ScanViewImage.aspx.cs: ``using System; using System.Collections.Generic;` `using System.Linq;` `using System.Web;` `using System.Web.UI;` `using System.Data;` `using System.Data.SqlClient;` `using System.Drawing;` `using System.Drawing.Imaging;` `using System.IO;` `using System.Runtime.InteropServices;`

public partial class ViewImage : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { //get the image id from the url string ImageId = Request.QueryString["img"]; //ImageId = "477"; //build our query statement string sqlText = "select im.ImageFile from stc.tblAddresses_Images im where im.ImageID = " + ImageId; string connString = "Provider=SQLOLEDB.1;Password=password;Persist Security Info=True;User ID=username;Initial Catalog=Carddatabase;Data Source=sqlserver"; System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection(connString); try{ conn.Open(); System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand(sqlText, conn); System.Data.OleDb.OleDbDataReader dr = cmd.ExecuteReader(); //open the database and get a datareader if (dr.Read()) //yup we found our image { //allow for on the fly conversion from TIFF to JPEG //Response.ContentType = "image/tiff";

            `const byte OLEbyte0 = 21;`
            `const byte OLEbyte1 = 28;`
            `byte[] abytPic = (byte[])dr[0];`
            `// Test for an OLE container header`
            `if ((abytPic[0] == OLEbyte0) && (abytPic[1] == OLEbyte1))`
            `{`


                `string Buffer = string.Empty;`
                `int i = 0;`
                `Buffer = ByteArrayToString(abytPic, EncodingType.ASCII);`
                `//Don't loop through - super duper slooooooooooowwwww!`
                `//for (i = 0; i < abytPic.Length; i++)`
                `//{`
                `//    Buffer = Buffer + Convert.ToChar(abytPic[i]);`
                `//}`

                `//if (Buffer.IndexOf("PBrush") > 0 )`
                `//{`
                `int BitmapHeaderOffset = Buffer.IndexOf("II");`
                `if (BitmapHeaderOffset > 0)`
                `{`
                    `//Calculate the beginning of the bitmap`
                    `int BitmapOffset = BitmapHeaderOffset;`

                    `byte[] abytStripped =`
                        `new byte[abytPic.Length - BitmapOffset];`
                    `//Move the bitmap into its own array`
                    `System.Buffer.BlockCopy(abytPic, BitmapOffset, abytStripped,`
                            `0, abytPic.Length - BitmapOffset);`
                    `//ReDim ArrBmp(UBound(Arr) - BitmapOffset)`
                    `//CopyMemory ArrBmp(0), Arr(BitmapOffset), UBound(Arr) -`
                    `// BitmapOffset + 1`

                    `//Return the bitmap`
                    `//`
                    `//to allow for on the fly TIFF to JPEG conversion`
                    `//`
                    `//Response.BinaryWrite(abytStripped);`
                    `//`
                    `//convert TIFF byte array to a memory stream pass to a bitmap and write as a jpeg`
                    `MemoryStream ms = new MemoryStream(abytStripped);`
                    `Bitmap objBitmap = new Bitmap(ms);`
                    `Response.ContentType = "image/jpeg";`
                    `objBitmap.Save(Response.OutputStream, ImageFormat.Jpeg);`
                    `Response.End();`
                `}`
            `}`
        `}`
    `}`
        `catch (Exception ex)`
    `{           }`
    `finally`
    `{`
        `conn.Close();`
    `}`
`}`
`public static string ByteArrayToString(byte[] bytes, EncodingType encodingType)`
`{`
    `System.Text.Encoding encoding = null;`
    `switch (encodingType)`
    `{`
        `case EncodingType.ASCII:`
            `encoding = new System.Text.ASCIIEncoding();`
            `break;`
        `case EncodingType.Unicode:`
            `encoding = new System.Text.UnicodeEncoding();`
            `break;`
        `case EncodingType.UTF7:`
            `encoding = new System.Text.UTF7Encoding();`
            `break;`
        `case EncodingType.UTF8:`
            `encoding = new System.Text.UTF8Encoding();`
            `break;`
    `}`
    `return encoding.GetString(bytes);`
`}`
`public enum EncodingType`
`{`
    `ASCII,`
    `Unicode,`
    `UTF7,`
    `UTF8`
`} `

`}``

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