I have been able to monitor websites with HTTP code and text check but I wanted to check if there is a way to check for an image as well from the HTML code(inspect image on website)?
Probably. You need to give way more information and sample event data.
For instance, https://www.worldtimebuddy.com/ - i'd like to check for the image - Like button which is on the top center of the page.
On inspect, i see -
<button id="icon-button" type="submit" class="inlineBlock _2tga _89n_ _8j9v" title="Like World Clock & Time Converter"><span class="_8f1i"></span><div class=""><span class="_3jn- inlineBlock _2v7"><span class="_3jn_"></span><span class="_49vg"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" class="_1pbq" color="#ffffff"><path fill="#ffffff" fill-rule="evenodd" d="M4.55,7 C4.7984,7 5,7.23403636 5,7.52247273 L5,13.4775273
C5,13.7659636 4.7984,14 4.55,14 L2.45,14 C2.2016,14 2,13.7659636
2,13.4775273 L2,7.52247273 C2,7.23403636 2.2016,7 2.45,7 L4.55,7 Z
M6.54470232,13.2 C6.24016877,13.1641086 6.01734614,12.8982791
6,12.5737979 C6.01734614,12.5737979 6.01344187,9.66805666 6,8.14398693
C6.01344187,7.61903931 6.10849456,6.68623352 6.39801308,6.27384278
C7.10556287,5.26600749 7.60281698,4.6079584 7.89206808,4.22570082
C8.18126341,3.8435016 8.52813047,3.4708734 8.53777961,3.18572676
C8.55077527,2.80206854 8.53655255,2.79471518 8.53777961,2.35555666
C8.53900667,1.91639814 8.74565444,1.5 9.27139313,1.5 C9.52544997,1.5
9.7301456,1.55690094 9.91922413,1.80084547 C10.2223633,2.15596568
10.4343097,2.71884727 10.4343097,3.60971169 C10.4343097,4.50057612
9.50989975,6.1729303 9.50815961,6.18 C9.50815961,6.18
13.5457098,6.17908951 13.5464084,6.18 C14.1635544,6.17587601
14.5,6.72543196 14.5,7.29718426 C14.5,7.83263667 14.1341135,8.27897346
13.6539433,8.3540827 C13.9452023,8.49286263 14.1544715,8.82364675
14.1544715,9.20555417 C14.1544715,9.68159617 13.8293011,10.0782687
13.3983805,10.1458495 C13.6304619,10.2907572 13.7736931,10.5516845
13.7736931,10.847511 C13.7736931,11.2459343 13.5138356,11.5808619
13.1594388,11.6612236 C13.3701582,11.7991865 13.5063617,12.0543945
13.5063617,12.3429843 C13.5063617,12.7952155 13.1715421,13.1656844
12.7434661,13.2 L6.54470232,13.2 Z"></path></svg><img class="_1pbs inlineBlock img" src="https://static.xx.fbcdn.net/rsrc.php/v3/yD/r/FEppCFCt76d.png" alt="" width="16" height="16"></span></span><span class="_49vh _2pi7">Like</span><span class="_5n6h _2pih" id="u_0_2_SU">14K</span></div></button>
OK. And how exactly are you monitoring that web site? Do you use any external tool which logs you ingest into splunk? Or do you use any add-on to spawn a HTTP request to that web server?