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• Perspective transformations

  9 juin 2010, par Mikko Koppanen — Imagick, PHP stuff

  Finally (after a long break) I managed to force myself to update the PHP documentation and this time it was distortImage code example. Things have been hectic lately but that does not quite explain the 6 months(?) break between this and the previous post. As a matter of a fact there is no excuse for such a long silence so I will try to update this blog a bit more often from now on.

  Back in the day I used to blog the examples and update the documentation if I remembered but I am trying to fix this bad habit. Most of the latest examples have been updated in to the manual. In the case of the two last examples I updated the documentation first and then blogged on the subject.

  I took some time to actually understand the perspective transformations properly using the excellent ImageMagick examples (mainly created by Anthony Thyssen) as a reference. The basic idea of perspective distortion seems simple : to distort the control points to new locations. Grabbing the syntax for Imagick was easy, an array of control point pairs in the form of :

  php

  < view plain text >

  1. array(source_x, source_y, dest_x, dest_y ... )

  The following example uses the built-in checkerboard pattern to demonstrate perspective distortion :

  php

  < view plain text >

  1. < ?php
  2. /* Create new object */
  3. $im = new Imagick() ;
  4.  
  5. /* Create new checkerboard pattern */
  6. $im->newPseudoImage(100, 100, "pattern:checkerboard") ;
  7.  
  8. /* Set the image format to png */
  9. $im->setImageFormat(’png’) ;
  10.  
  11. /* Fill background area with transparent */
  12. $im->setImageVirtualPixelMethod(Imagick: :VIRTUALPIXELMETHOD_TRANSPARENT) ;
  13.  
  14. /* Activate matte */
  15. $im->setImageMatte(true) ;
  16.  
  17. /* Control points for the distortion */
  18. $controlPoints = array( 10, 10,
  19.             10, 5,
  20.  
  21.             10, $im->getImageHeight() - 20,
  22.             10, $im->getImageHeight() - 5,
  23.  
  24.             $im->getImageWidth() - 10, 10,
  25.             $im->getImageWidth() - 10, 20,
  26.  
  27.             $im->getImageWidth() - 10, $im->getImageHeight() - 10,
  28.             $im->getImageWidth() - 10, $im->getImageHeight() - 30) ;
  29.  
  30. /* Perform the distortion */ 
  31. $im->distortImage(Imagick: :DISTORTION_PERSPECTIVE, $controlPoints, true) ;
  32.  
  33. /* Ouput the image */ 
  34. header("Content-Type : image/png") ;
  35. echo $im ;
  36.  ?>

  Here is the source image :
  

  And the result :
  

• Of ctors and dtors

  18 février 2011, par Multimedia Mike — Programming, Sega Dreamcast

  I haven’t given up on the Sega Dreamcast programming. I was able to compile a bunch of homebrew code for the DC many years ago and I can’t make it work anymore. Again, I was working with a purpose-built, open source RTOS named KallistiOS (or KOS). I can make the programs compile but not run. I had ELF files left over from years ago which still executed. But when I tried to build new ELF files, no luck— the programs crashed before even reaching my main() function.

  I found the problem : ELF files are comprised of a number of sections and 2 of these sections are named ’.ctors’ and ’.dtors’ which stand for constructors and destructors. The KOS RTOS performs a manual traversal of .ctors section during program initialization and this is where things go bad. The traversal code doesn’t seem to account for a .ctors section that only contains a single entry. I commented out the function that does the traversal and programs started to work, at least until it was time to exit the program and return control to the program loader. That’s when the counterpart .dtors section traversal code ran and demonstrated the same problem. I’ll exhibit the problematic code at the end of this post.

  So I’m finally tinkering with Sega Dreamcast programming once again and with a slightly better grasp of software engineering than the first time I did this.

  Portable and Compatible C ?
  If nothing else, this low-level embedded stuff exposes you to some serious toolchain arcana, the likes of which you will likely never see working strictly in the desktop arena.

  Still, this exercise makes me wonder why C code from a decade ago doesn’t compile reliably now. Part of it is because gcc has gotten stricter about the syntax it will accept. In the case of this specific crashing problem, I suspect it comes down to a difference in the way the linker generates the final ELF file. I’ve written a list of items I have had to modify in the KOS codebase in order to get it to compile on more recent gcc versions. I wonder if it would be worth publishing the specifics, or if anyone would ever find the information useful ? Oh, who am I kidding ? Of course I’ll write it up, perhaps publish a new version of the code, if only because that’s the best chance I have of finding my own work again some years down the road.

  Problematic C Code
  See if this code makes any sense to you. It somehow traverse a list of 32-bit function pointers (in different directions, depending on constructors or destructors), executing each in turn. However, it appears to fall over if the list of pointers consists of a single entry.
  

  PLAIN TEXT

  C :

  1. typedef void (*fptr)(void) ;
  2.  
  3. static fptr ctor_list[1] __attribute__((section(".ctors"))) = { (fptr) -1 } ;
  4. static fptr dtor_list[1] __attribute__((section(".dtors"))) = { (fptr) -1 } ;
  5.  
  6. /* Call this to execute all ctors */
  7. void arch_ctors() {
  8.     fptr *fpp ;
  9.  
  10.     /* Run up to the end of the list (defined by crtend) */
  11.     for (fpp=ctor_list + 1 ; *fpp != 0 ; ++fpp)
  12.          ;
  13.  
  14.     /* Now run the ctors backwards */
  15.     while (—fpp> ctor_list)
  16.         (**fpp)() ;
  17. }
  18.  
  19. /* Call this to execute all dtors */
  20. void arch_dtors() {
  21.     fptr *fpp ;
  22.  
  23.     /* Do the dtors forwards */
  24.     for (fpp=dtor_list + 1 ; *fpp != 0 ; ++fpp )
  25.         (**fpp)() ;
  26. }

• CRO Audit : Increase Your Conversions in 10 Simple Steps

  25 mars 2024, par Erin

  You have two options if you’re unhappy with your website’s conversion rates.

  The first is to implement a couple of random tactics you heard on that marketing podcast, which worked for a business completely unrelated to yours. 

  The other is to take a more systematic, measured approach. An approach that finds specific problems with the pages on your site and fixes them one by one. 

  You’re choosing the second option, right ?

  Good, then let’s explain what a conversion rate optimisation audit is and how you can complete one using our step-by-step process.

  What is a CRO audit ?

  A conversion rate optimisation audit (CRO audit) systematically evaluates your website. It identifies opportunities to enhance your website’s performance and improve conversion rates. 

  During the audit, you’ll analyse your website’s entire customer journey, collect valuable user behaviour data and cross reference that with web analytics to find site elements (forms, calls-to-actions, etc.) that you can optimise.

  

  It’s one (and usually the first) part of a wider CRO strategy. 

  For example, an online retailer might run a CRO audit to discover why cart abandonment rates are high. The audit may throw up several potential problems (like a confusing checkout form and poor navigation), which the retailer can then spend time optimising using A/B tests. 

  Why run a CRO audit ?

  A CRO audit can be a lot of work, but it’s well worth the effort. Here are the benefits you can expect from running one.

  Generate targeted and relevant insights

  You’ve probably already tested some “best practice” conversion rate optimisations, like changing the colour of your CTA button, adding social proof or highlighting benefits to your headlines. 

  These are great, but they aren’t tailored to your audience. Running a CRO audit will ensure you find (and rectify) the conversion bottlenecks and barriers that impact your users, not someone else’s.

  Improve conversion rates

  Ultimately, CRO audits are about improving conversion rates and increasing revenue. Finding and eliminating barriers to conversion makes it much more likely that users will convert. 

  But that’s not all. CRO audits also improve the user experience and customer satisfaction. The audit process will help you understand how users behave on your website, allowing you to create a more user-friendly customer experience. 

  A 10-step process for running your first CRO audit 

  Want to conduct your first CRO audit ? Follow the ten-step process we outline below :

  

  1. Define your goals

  Start your CRO audit by setting conversion goals that marry with the wider goals of your business. The more clearly you define your goals, the easier it will be to evaluate your website for opportunities. 

  Your goals could include :

  • Booking more trials
  • Getting more email subscribers
  • Reducing cart abandonments

  You should also define the specific actions users need to take for you to achieve these goals. For example, users will have to click on your call-to-action and complete a form to book more trials. On the other hand, reducing cart abandonments requires users to add items to their cart and click through all of the forms during the checkout process. 

  If you’re unsure where to start, we recommend reading our CRO statistics roundup to see how your site compares to industry averages for metrics like conversion and click-through rates. 

  You’ll also want to ensure you track these conversion goals in your web analytics software. In Matomo, it only takes a few minutes to set up a new conversion goal, and the goals dashboard makes it easy to see your performance at a glance. 

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  2. Review your analytics

  With your goals in mind, the next step is to dive into your website analytics and identify pages that need improvement.

  Consider the following conversion metrics when analysing pages :

  • Conversion rate
  • Average time on page
  • Average order value
  • Click-through rate

  Ensure you’re analysing metrics aligning with the goals you set in step one. Average order value could be a great metric to track if you want to reduce cart abandonments, for example, but it’s unsuitable to get more email subscribers.

  3. Research the user experience

  Next, you’ll want to gather user experience data to better understand how potential customers use your website and why they aren’t converting as often as you’d like. 

  You can use several tools for user behaviour analysis, but we recommend heatmaps and session recordings.

  Heatmaps visually represent how users click, move and scroll your website. It will show where visitors place their attention and which page elements are ignored. 

  Take a look at this example below from our website. As you can see, the navigation, headline and CTA get the most attention. If we weren’t seeing as many conversions as we liked and our CTAs were getting ignored, that might be a sign to change their colour or placement. 

  

  Session recordings capture the actions users take as they browse your website. They let you watch a video playback of how visitors behave, capturing clicks and scrolls so you can see each visitor’s steps in order. 

  Session recordings will show you how users navigate and where they drop off. 

  4. Analyse your forms

  Whether your forms are too confusing or too long, there are plenty of reasons for users to abandon your forms. 

  But how many forms are they abandoning exactly and which forms are there ?

  That’s what form analysis is for. 

  Running a form analysis will highlight which forms need work and reveal whether forms could be contributing to a page’s poor conversion rate. It’s how Concrete CMS tripled its leads in just a few days.

  Matomo’s Form Analytics feature makes running form analysis easy.

  

  Just open up the forms dashboard to get a snapshot of your forms’ key metrics, including average hesitation time, starter rate and submission rates. 

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  Get the web insights you need, without compromising data accuracy.

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  5. Analyse your conversion funnel

  Next, analyse the conversion funnel to see if there’s an obvious bottleneck or several pages where visitors abandon your desired action. Common conversion abandonment points are shopping carts and forms.

  

  For example, you could find there is a drop-off in conversions between checking out and making a purchase or between booking a demo and signing up for a subscription. Understanding where these drop-offs occur lets you dig deeper and make targeted improvements.

  Don’t worry if you’ve got a very long funnel. Start at the bottom and work backward. Problems with the pages at the very end of your funnel tasked with converting customers (landing pages, checkout pages, etc.) will have the biggest impact on your conversion rate. So, it makes sense to start there. 

  6. Analyse campaigns and traffic sources (marketing attribution)

  It’s now time to analyse traffic quality to ensure you’re powering your conversion optimisation efforts with the best traffic possible. 

  This can also help you find your best customers so you can focus on acquiring more of them and tailoring your optimisation efforts to their preferences. 

  Run a marketing attribution report to see which traffic sources generate the most conversions and have the highest conversion rates. 

  

  Using marketing attribution is crucial here because it gives a fuller picture of how customers move through their journey, recognising the impact of various touchpoints in making a decision, unlike last-click attribution, which only credits the final touchpoint before a conversion.

  7. Use surveys and other qualitative data sources

  Increase the amount of qualitative data you have access to by speaking directly to customers. Surveys, interviews and other user feedback methods add depth and context to your user behaviour research.

  Sure, you aren’t getting feedback from hundreds of customers like you do with heatmaps or session recordings, but the information can sometimes be much richer. Users will often tell you outright why they didn’t take a specific action in a survey response (or what convinced them to convert). 

  Running surveys is now even easier in Matomo, thanks to the Matomo Surveys third-party plugin. This lets you add a customisable survey popup to your site, the data from which is automatically added to Matomo and can be combined with Matomo segments.

  8. Develop a conversion hypothesis

  Using all of the insights you’ve gathered up to this point, you can now hypothesise what’s wrong and how you can fix it. 

  Here’s a template you can use :

  

  This could end up looking something like the following :

  Based on evidence gathered from web analytics and heatmaps, moving our signup form above the fold will fix our lack of free trial signups, improving signups by 50%.

  

  Make sure you write your hypothesis down somewhere. Matomo lets you document your hypothesis when creating an A/B test, so it’s easy to reflect on when the test finishes. 

  9. Run A/B tests

  Now, it’s time to put your theory into practice by running an A/B test.

  Create an experiment using a platform like Matomo that creates two different versions of your page : the original and one with the change you mentioned in your hypothesis. 

  There’s no set time for you to run an A/B test. Just keep running it until the outcome is statistically significant. This is something your A/B testing platform should do automatically. 

  A statistically significant result means it would be very unlikely the outcome doesn’t happen in the long term.

  

  As you can see in the image above, the wide header variation has significantly outperformed both the original and the other variation. So we can be pretty confident about making the change permanent. 

  If the outcome of your A/B test also validates your conversion hypothesis, you can implement the change. If not, analyse the data, brainstorm another hypothesis and run another A/B test. 

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  10. Monitor and iterate

  You need to develop a culture of continuous improvement to succeed with conversion rate optimisation. That means constantly monitoring your conversion goals and running tests to improve your metrics. 

  While you don’t need to run a conversion audit every month, you should run audits regularly throughout the year.

  How often should you conduct a CRO audit ? 

  You should conduct a CRO audit fairly regularly. 

  We recommend creating a CRO schedule that sees you run a CRO audit every six to 12 months. That will ensure you continue identifying problem pages and keeping your conversion rates competitive. 

  Regular CRO audits will also account for evolving consumer behaviours, changes in your industry and your own business goals, all of which can impact your approach conversion rate optimisation. 

  Run your CRO audit with Matomo

  A CRO audit process is the only way you can identify conversion optimisation methods that will work for your site and your target audience. It’s a methodical, data-backed strategy for making targeted improvements to send conversion rates soaring. 

  There are a lot of steps to complete, but you don’t need dozens of tools to run a CRO audit process. 

  Just one : Matomo.

  Unlike other web analytics platforms, like Google Analytics, Matomo has the built-in tools and plugins to help with every step of the CRO audit process, from web analytics to conversion funnel analysis and A/B testing. With its accurate, unsampled data and privacy-friendly tracking, Matomo is the ideal choice for optimising conversions. 

  Learn how to increase your conversions with Matomo, and start a free 21-day trial today. No credit card required.

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