Random image to prevent automatic registration

I am doing a travel blog in coldfusion and I would like to prevent automatic registration.
Does anyone kindly provide some tutorial of random image with security code to prevent automatic registration?

Thanks in advance!

 

Sure...I use a web service provided by Easycfm.com. In a nut shell, I consume the web service - this gives me a file name and the text equivalent. (This is done from the registration form template). I set the text value of the captcha using a session variable. After the form is posted, I compare the user entry to the session variable to ensure they match.

EasyCFM.com has good example code:
<cfscript>
// Define the values to pass to the object
theight = "350";
twidth = "350";
tfont = "Verdana";
tfontColor = "Black";
tfontSize = "12";
tfontOpacity = 100;
tbgcolor1 = "white";
tbgcolor2 = "white";
tquality = 10;
tdistortionMethod = 1;
tXPos = 10;
tYPos = 10;
</cfscript>

<cfinvoke
webservice="http://www.easycfm.com/webservices/captcha.cfc?wsdl"
method="generateCaptcha"
returnvariable="aHashMap">
<cfinvokeargument name="height" value="#tHeight#"/>
<cfinvokeargument name="width" value="#tWidth#"/>
<cfinvokeargument name="font" value="#tFont#"/>
<cfinvokeargument name="fontColor" value="#tFontColor#"/>
<cfinvokeargument name="fontSize" value="#tfontSize#"/>
<cfinvokeargument name="fontOpacity" value="#tfontOpacity#"/>
<cfinvokeargument name="bgcolor1" value="#tbgcolor1#"/>
<cfinvokeargument name="bgcolor2" value="#tbgcolor2#"/>
<cfinvokeargument name="quality" value="#tquality#"/>
<cfinvokeargument name="distortionMethod" value="#tdistortionMethod#"/>
<cfinvokeargument name="XPos" value="#tXPos#"/>
<cfinvokeargument name="YPos" value="#tYPos#"/>
</cfinvoke>

<!--- set the session variable --->
<cfset session.CAPTCHAWORD=#aHashMap.CAPTCHAWORD#>
<!--- show the image --->
<img src="#aHashmap.image#">

In the reg form:
<input type="text" name="catchaword">

In the action template:
<cfif form.captchaword NEQ session.catpchaword>
(do something)
</cfif>

 

I'd just like to point out that CFMX 8 (in beta now, to be released in August or September) has this functionality built-in.

 

Yup, it's a function of the new CFIMAGE tag!

 

thank you very much. Seems like CFMX 8 has enchanced many features!

 

Even thought it's in beta, can anyone download it? If so, anyone have a link? Would greatly appreciate it. Thanks!

 

It is a closed beta program for now; not sure when or if it will become public.