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Compare image instead of pixel color ?

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When I want to see if a file changes I use HTTP Methods which you can do in an external script. The HTTP request will get you the whole file but there's a method that will only return the headers called "HEAD". The response headers usually have a "Last-Modified header. I just did one on my websites logo and I can see it was last modified on "Sun, 28 Feb 2021 00:24:18 GMT". I would cast that in the script to a decimal or longest-to-shortest text date format and compare. With this you can see if a file has changed without having to download it. 

If you don't want to do an external script, you could download the file and check it's metadata for a creation date tag. 

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Here's a macro to demonstrate. If I enter "http://bluepointdesign.com/images/logo.jpg" I can see these headers. Most of these can be useful. And I think the ETag header is essentially a version number. I know it's used on cache control so I think it's what you browser uses to decide if it needs to retrieve the file or if it can be loaded from cache. If so, you can use that to decide if the file, a graphic in this case, has changed. 


Content-Length: 37641
Content-Type: image/jpeg
Last-Modified: Sun, 28 Feb 2021 00:24:18 GMT
Accept-Ranges: bytes
ETag: "c5be40d68dd71:0"
Server: Microsoft-IIS/8.5
X-Powered-By: ASP.NET
X-Powered-By-Plesk: PleskWin
Date: Tue, 27 Apr 2021 17:44:01 GMT

HTTP Headers.mex

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Sorry, took me a while to answer.


It's a very cool script !!


Unfortunately in my case, it's text that updates, and after a loading time that seems to be in jquery.


Here an example with the equivalent, some text which changes and I need to monitor a change, and the kind of jquery which adds a loading to the page: https://eu.tamrieltradecentre.com/pc/Trade/SearchResult?SearchType=Sell&ItemID=&ItemNamePattern=rusé&ItemCategory1ID=1&ItemCategory2ID=2&ItemCategory3ID=18&ItemTraitID=11&ItemQualityID=&IsChampionPoint=false&LevelMin=&LevelMax=&MasterWritVoucherMin=&MasterWritVoucherMax=&AmountMin=&AmountMax=&PriceMin=&PriceMax=&SortBy=LastSeen&Order=desc


I also have an other exemple if needed, but that's exactly the kind of page I need to monitor. 


But wait... Your script maybe works..? I'll try this :) that's a very cool one. Edit : not for the delay in jquery it seems. 

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You said "Image", not "Text". And image is a graphic file. Well that was a waste of my time. 


Everything is a request. Hit F12 on your keyboard and watch the requests in the network tab. If it's a GET you can get the web page with the HTTP GET command. Then simply compare the parts from the previous GET and see if it changes. However I see they use reCAPTCHA so that might not work. I use the method even to get the JSON data packages they scripts on the web page use. Often I can tweak the parameters to get all sorts of things they didn't intend.


I am guessing that after a period of time it automatically refreshes. There is text on the new page that is different than the pervious and you want to know when that occurs. Then simply do a CTRL+a and clipboard copy. All the visible text will be in there. The page you sent looks like this. 


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But I am unsure of what you are trying to do. 


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On 4/27/2021 at 6:29 PM, ikodan said:

I need to compare 2 pages in order to monitor the changes. 


I said that when you asked me what I wanted to do. The first question was about an image, because I planed to monitor the change in the page, with a "wait 5 sec" (recaptcha), and compare a picture of the page before and after. You asked me more precision when you tried to help me. 


In this exemple, I have to detect when there is a new item added in the page, but I can't copy paste all the page and compare, because there is timers on each item, "last seen 5 minutes ago", and the macro will detect a change that I don't need.  


Anyway thank you for your help... 

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