Hi rani,

Using the below article i have created the example.

Simple Image Slider (Carousel) in AngularJS

Check this example. Now please take its reference and correct your code.

Database

For this example i am making use of a table named tblFiles whose schema is defined as follows.

You can download the database table SQL by clicking the download link below.

Download SQL file

HTML

<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.9/angular.min.js"></script>
<script type="text/javascript">
    var app = angular.module('MyApp', [])
    app.controller('MyController', function ($scope, $http, $interval) {
        $http.post("Default.aspx/GetImages", { headers: { 'Content-Type': 'application/json'} })
        .then(function (response) {
            $scope.Images = response.data.d;
        });
        $scope.Image = null;
        var index = 0;
        $interval(function () {
            $scope.Image = $scope.Images[index];
            $scope.$apply();
            index++;
            if (index > $scope.Images.length - 1) {
                index = 0
            }
        }, 1000);
    });
</script>
<div ng-app="MyApp" ng-controller="MyController" style="text-align: center">
    <img ng-src="{{'data:image/png;base64,' + Image.Data}}" ng-show="Image.Data" />
    <br />
    <span>{{Image.Name}}</span>
</div>

Namespaces

C#

using System.Configuration;
using System.Data.SqlClient;
using System.Web.Services;

VB.Net

Imports System.Configuration
Imports System.Data.SqlClient
Imports System.Web.Services

Code

C#

[WebMethod]
public static List<object> GetImages()
{
    List<object> files = new List<object>();
    string sql = "SELECT id,Name,Data FROM tblFiles";
    using (SqlConnection conn = new SqlConnection())
    {
        conn.ConnectionString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlCommand cmd = new SqlCommand(sql))
        {
            cmd.Connection = conn;
            conn.Open();
            using (SqlDataReader sdr = cmd.ExecuteReader())
            {
                while (sdr.Read())
                {
                    files.Add(new
                    {
                        Id = sdr["id"].ToString(),
                        Name = sdr["Name"].ToString(),
                        Data = Convert.ToBase64String((byte[])sdr["Data"])
                    });
                }
            }
            conn.Close();
        }

        return files;
    }
}

VB.Net

<WebMethod()>
Public Shared Function GetImages() As List(Of Object)
    Dim files As List(Of Object) = New List(Of Object)()
    Dim sql As String = "SELECT id,Name,Data FROM tblFiles"
    Using conn As SqlConnection = New SqlConnection()
        conn.ConnectionString = ConfigurationManager.ConnectionStrings("constr").ConnectionString
        Using cmd As SqlCommand = New SqlCommand(sql)
            cmd.Connection = conn
            conn.Open()
            Using sdr As SqlDataReader = cmd.ExecuteReader()
                While sdr.Read()
                    files.Add(New With {
                        .Id = sdr("id").ToString(),
                        .Name = sdr("Name").ToString(),
                        .Data = Convert.ToBase64String(CType(sdr("Data"), Byte()))
                    })
                End While
            End Using
            conn.Close()
        End Using

        Return files
    End Using
End Function

Screenshot