1080p, 720p, 1080i, 480p: Understanding the Numbers


You must have seen these numbers referring to quality of laptop screens, TVs or monitors.  You might argue associating these numbers with video quality as well. Oh, wait did you also see these numbers written on a digital camera? The numbers are indeed confusing.  So an easy to read yet technical description on these numbers  –  just read ahead!

The letters suffixing the these numbers. The i in ‘1080i’ stands for ‘Interlaced’.   Have a look at the pictures below:




The 2 parts of the same picture:








A word of caution before we proceed – I’ll be talking in terms of  ‘Video Quality’  first. There is the original picture – P1.  Pictures P2 and P3 are say the blocks of a puzzle which combines to form p1.    If the  pictures P2 and P3 are flipped at a very high frequency, the human eye cannot distinguish if these where two different pictures at all  and what you see is a single picture as in picture 1.  But a video is not a single image. Right, a video is a collection of pictures flipping at a very high rate.When you pause a video you get some still image on your screen. The image that was being projected was a combination of two pictures as I showed above. So at any point in the video, only half the picture is being projected, which is obviously being flipped so fast that you can’t make out. To get a bleak idea on how it may feel – save these pictures in a new folder and then change them using the arrow keys in Windows Picture Viewer.

You can also compare interlaced projection to painting a picture – with odd lines painted first followed by the even lines.

Now for the letter ‘p’. ‘p’ stands for ‘Progressive’.  As the names suggests pictures are progressively flipped in such type of a video. Unlike an interlaced projection where virtually only half of the image is screened at any point of time in progressive projection complete pictures are screened.

So you may  think, obviously the progressive is a better quality any day.  A full picture being flipped is obviously better than a half. I recommend you to read ahead before you make a decision.

Now for the numbers. We can’t leave the numbers behind in our discussion of progressive and interlaced projections. 1080 corresponds to the resolution of 1,920×1,080 pixels or 1080 lines of vertical resolution. 720p stands for  1280 x 720 pixels or 720 pixels of vertical resolution. So 1080i would mean a resolution of 1920×1080 pixels being projected in a interlaced manner and 1080p would mean the same resolution being progressively projected. Now we can safely say that 1080p is a better quality projection than 1080i. But there is ambiguity over the 720p projection. Some say that the 1080i quality is better than the 720p while others believe that progressive projection improves video quality and hence 720p is better than 1080i. However 1080i is definitely better than 420p. Even though 420p is progressively projected – the resolution is very low with just 640×480 pixels.

Talking in terms of the displays – the TV’s, the computer monitors and in terms of the pictures that are clicked by modern day digital cameras. As I mentioned 1080 is equivalent to 1920x 1080 pixels, but your screen should support that resolution to display such high quality. So if your screen supports that kind of resolution you’ll find it labelled HD Display or HDTV for a TV. (There are other factors determining if a display is HD or not – but we leave that discussion of frequencies and bandwidths for this post). Even if your display is not HD capable it does plays the HD videos or display HD Pictures. That’s where referring the quality in terms of lines of resolution comes into play. Your picture or video may have a resolution of 1080/720/480 vertical lines with no consideration of the display it will be projected on. The quality of the output is retained irrespective of the display.  You’ll feel the difference between the quality of the videos of different on most screens (barring the CRT displays – again a long explanation on why).

You might like calling these numbers with some special names:

High Definition or HD for 1080p.
Standard Definition for 720p. Also called HD in 720p.
Enhanced Definition for 480p.

My take on content quality is  1080p>720p ≈1080i>480p.  I hope you find this information helpful for your next ‘Gadget Shopping’!


Emerging Trends and Technologies: The App Stores


There is an app for this. There is an app for that. Apple  says there is an app for almost everything on the iPhone (or more correctly I should say the iOS devices). I’d like to modify that a little – There is app for almost everybody. Apple have no doubt been the pioneers of the ‘App Store’ and lead the market with over a million apps and a greater downloads.


Now let me not crib about other companies ‘copying, following or taking inspirations ‘ from the Apple idea ( Apple might now be used to it! ) but lets take a moment and realize that how the mobile phone applications are changing the way we use our phones, much the way applications did in the mid nineties (the era of Windows 95 and Windows 98) to the PC. Remember taking a ‘floppy full’ of those bow and arrow games or the Aladdin and Mario Games from your friends. Let’s see how this development affects the developers, the mobile operators, the handset manufacturers and most importantly us – the consumers.

Talking about the mobile operators. Airtel has an App Store, Vodafone has an App store and you definitely might have seen the Aircel ads recently. Excuse me for using the word ‘App Store’ – it is much like calling the (musical instrument) keyboard a CASIO. A store where applications are sold – the App Store for Apple , the Android Market for Google or the OVI (Ovee – the correct pronunciation) from Nokia . Even if you don’t have a handset which by defaults links you to the company app store or perhaps doesn’t have one – your operator is reaching out to you.  Common, how does the presence of these operator app stores affect at all? Well there are more people talking about the features in terms of downloads instead of the ones listed at the back of  the cell phone box.  “Yeh feature to download karna padega”.

Next the manufacturers. I don’t have any access to the inside scoop of the policies being implemented by the manufactures but what you can definitely see is that there are more of the ‘applications store’  phones in the market than the ones which just focused on playing your music and taking pictures.  The manufacturers have their own application markets. Nokia has one – the OVI store as I mentioned above, the Windows Market Place – from Microsoft for there Windows powered phones and others. The app store not only gets them more profits but reduce the burden of powering your handsets with different software. So if the Motorolla shipped a dedicated facebook app with their phone – Nokia doesn’t have to launch a new ‘Facebook’ phone.

The Developers. Here is an interesting calculation to show to you. An app popularly sells for $ 0.99. 1 Billion Apps were downloaded in just 9 monts on the Apple App Store. If you have  great idea, and your app gets on the Top 25 List or tops it’s category or even makes it to the ‘App of the week’ section – chances are that you’ll sell say roughly a 4000 copies of your app worldwide. 4000 because the no of apps on the App Store are 2,50,000. So number of Downloads/No of Apps.

Now check this:

$0.99 x 4000 = $3960 or Rs. 1,82,160

A good developer would have is app on multiple platforms – Nokia, Android and Blackberry.

$3960 x 3 = $11880 =  Rs. 5,46,880

Add to this the operator app stores. The value goes up further!  ” One  App gets over $11,000″. Though developers get only 70% of it on most app stores!

Yeah, these calculations are completely baseless. But you see if even some pie of that is correct, the amount is huge :P.

It’s not only about the money. There were apps earlier and there were no stores but some malicious websites that sold you these applications. What happened was most users were reluctant to visit these websites, download them first on the computer and  transfer them to the phone. Application development for mobile phone had little space in the market. Who’d know if you made a Criss Cross app for the Nokia N72? With these application markets, developers just need to focus on developing the app. The application markets take care of the popularity.

Let’s see how it was buying a phone couple of years back.

– New phone launched in the market.

– Huge hype and excitement.

– Every 3rd person gets the same phone.

– The phone has some very basic features. You explore them  within a week.

– Games. 4? 5? Pre-installed games. Take a couple of more from friends.

– 6 Months Later. Phone prices dropped by 25 %.

– No new games/applications.

– New handset, with new games and new applications.

– Get bored with your handsets, perhaps even before the warranty expires.

Now, with app stores on your phone, you can add more power to your existing handset with  just a click. No going to the websites and transferring data through PC Suites. So you buy a phone today and keep adding new features to it every month!

What do you feel about the ‘App Revolution’. Let me know! Would love to hear from you…