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Sense 5 Toolbox - the best customizer for HTC Sense 5 based ROMs

Posted by Unknown Thursday, September 26, 2013 0 comments

If you haven't used it yet - you really should. I'm talking about the "Sense 5 Toolbox" application, made initially for Android Revolution HD. In the last few weeks the popularity of this application reached an unexpected level, and we believe it's a reason to celebrate.

More details about the Sense 5 Toolbox can be found on this blog, under "Sense 5 Toolbox" link on the right panel. Or, just click here.

Why Sense 5 Toolbox?

The application is an answer for 2 basic issues: many users wants to customize their OS as much as possible, but currently available solutions similar to Sense 5 Toolbox are very limited when it comes to the possibility of using them on most custom ROMs.

Android Revolution HD is known to be a "stock-looking" ROM, which was always the most important aspect for many users, who were looking for a stable and well known custom ROM. However, having a custom ROM with such popularity brought our attention to many users, who were looking for a stable custom ROM, but also with a little touch of customisation features - like displaying the battery percentage, or being able to re-order or re-design some part of the UI. This leads to two different approaches:

having a custom ROM full of many more or less advanced features coded into the framework, which always ends up with all sort of issues, bugs, waiting a long time for a new ROM version based on freshly released official OS update etc; or
having a custom ROM like Android Revolution HD, close to stock with just a few changes under the hood to make Android users life easier, combined with a standalone application like Sense 5 Toolbox.

The result is what most users are looking for: stock looking by default, a stable and optimized custom ROM - but with the capability to change many things inside the OS.

With Android Revolution HD and Sense 5 Toolbox you have:

fast updates when a new OS is released/leaked,
a stable custom ROM,
the capability to customize your OS,
great performance because of the tweaks under the hood,
many features not available on the stock ROM.

The Sense 5 Toolbox is under continuous development. More and more features are coming with each new release and the "to do" list is quite large.

In the background, another project is still alive and under heavy development too. I'm referring to the "Revolution Toolbox" application, announced in this post few weeks ago. It's still being tested, however we are getting close to the first public beta. Just one little secret I can say out loud now - Revolution Toolbox and Sense 5 Toolbox will "connected" in a particular way. Can't say more for now, stay tuned!

Have any questions or comments? Feel free to share! Also, if you like this article, please use media sharing buttons (Twitter, G+, Facebook) below this post!

HTC Desire HD looking for a new owner!

Posted by Unknown 0 comments

It's been a great adventure since 14th November 2010, when I started my first Android Revolution HD thread. The first officially supported device was HTC Desire HD. In three years this thread reached almost 15 million visits and more than 70 thousand replies. That's probably the most popular thread on the entire XDA Developers' Forum.

I have many devices laying in my closet, so I decided to sell some of them. Every electronic device loses some of its value with each passing year. I have two options: I can sell my HTC Desire HD for some regular market price (around $150) here in my country, or I can send it outside my country, to a person who will decide to pay more as a kind of donation to support Android Revolution HD project.

The device itself is in perfect condition, fully working and without any scratches. You can see the actual pictures of the device in the gallery.

If you would like to get the first Android Revolution HD device, please offer your price by sending an e-mail to android.revolution.hd.app@gmail.com

Thanks!

Android 4.3 update for HTC One

Posted by Unknown 0 comments

HTC One finally received official Android 4.3 Jelly Bean update from HTC. So far the update is available for only 2 CID/MID variants:

x.xx.709.x for Asia TW (Taiwan) - from 2.24.709.1 to 3.18.709.2
x.xx.1540.x for Developer Edition - from 1.29.1540.17 to 3.22.1540.1

Both OTA updates are around 550 MB so it's pretty large update. Keep in mind you can't flash particular OTA update on the device with different CID/MID. That said, international users (WWE x.xx.401.x) still needs to wait for proper OTA package.

In a mean time we had some preview of what's coming along with Android 4.3 for HTC One in a leaked 3.17.502.2 software for Cingular US (United States). The reason why x.xx.502.x software was ready in a first place was the release of HTC One blue variant for U.S. AT&T network provider. You can find the latest Android Revolution HD 21.0 based on this software under this link.

If you don't want to wait for WWE update, there might be something special coming today for all HTC One users. Android Revolution HD 22.0 should be available soon in my xda-developers thread under this link.

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NFC vs. Bluetooth (and why Bluetooth is better)

Posted by Unknown Monday, September 16, 2013 0 comments

NFC is by no means a new 2013 invention, despite what the recent influx in NFC enabled phones may lead you to believe.

History of NFC

In 1983, Radio Frequency Identification was patented. This the earliest form of NFC, and features in contactless credit cards. A drawback of RFID was that it did not support two-way communication, which makes it less secure than NFC. In 2003, NFC was approved as an ISO/IEC standard; in 2004 Nokia set up the NFC Forum (which can be found <here>). Designed to promote the uses of NFC and ensure that new devices were compliant, the website now has over 170 corporate members including mobile manufacturers, banks and mobile network providers.

Unveiled in 2007 at the Consumer Electronics Show in Las Vegas, the Nokia 6131 NFC was the worlds first fully integrated NFC mobile device. This led the way for more NFC enabled phones, with 100 million shipped in 2012. In 2013, this rose by 156% to a total of 400 million devices globally. It is estimated that by 2015, 53% of phones will be NFC-enabled.

History of Bluetooth

Bluetooth is an older technology than NFC as the name was adopted in 1998 - a full 5 years before NFC was approved. The Bluetooth SIG (Special Interest Group) was established in the same year to promote Bluetooth and gain corporate partners. The SIG was party to 400 members by the end of 1998, and by 2013 it has reached over 19,000 members, including high profile companies such as LG and Apple. The first mobile device to have Bluetooth was the Ericsson T36 in 2000, which allowed it to pair with the first headset which was also released that year. Now in 2013, over 20 million Bluetooth enabled devices are shipped per week, with the total number exceeding 2.5 billion. This means that Bluetooth is still much more widely used than NFC, although this gap is set to narrow substantially throughout the next 5 years. Bluetooth has gone through a number of advancements over the years and is currently at version 4.0, which is supported in Android 4.3. This is not new however, and has been around since the iPhone 4S. A detailed article on the inclusions of Bluetooth 4.0 will follow.

Security

In terms of security, both NFC and Bluetooth are fairly secure. Bluetooth has a range of 9.75 meters (or 32 feet), while NFC has a maximum range of 4cm. This means that NFC has the edge, due to the fact that a hacker would need to be right next to you for an attack to work, while Bluetooth has a longer working range.

NFC doesn't come with built-in security measures, however the limited range offers great protection. NFC is also extremely sensitive to direction, and even a slight directional movement on the device will disrupt the signal. NFC is only active when it needs to be, meaning that even if you leave it on in your pocket, the NFC chip isn't actually functioning. This further increases security.

Unfortunately, NFC can be exploited in other ways. Take a smart tag in a magazine, programmed to open the webpage on your phone. A hacker can manipulate this and change the code to instead make it send premium text messages, costing you hundreds in a matter of minutes. The worst part of this is that you wouldn't even know until your monthly bill arrived. To avoid scams such as these, try to avoid using tags which aren't behind a barrier, as these are less easily accessible and harder to tamper with.

Another concern with NFC is privacy. When you pay for a product in-store, you are identified and your purchase information is stored. The shop then uses this information to send you advertisements based on products you may find desirable. The privacy concern is that shops can then sell this information to third parties, who may in return send unsolicited spam.

Bluetooth implements an authentication mechanism based on the SAFER+ block cipher. This means that when two devices attempt to connect, they will both need to enter the same numeric PIN code for the transfer or connection to take place. This ensures that a malicious connection cannot take place without the victims knowledge and acceptance. Two devices can be 'paired' which means that they will no longer require entry of a code. This is useful for allowing a trusted device to connect easily, but can open security risks if a paired device is compromised.

Bluejacking is the process of sending a file to an unsuspecting victim, which is usually harmless (like rick rolling) but can occasionally be malicious such as the ability to take control of a device and call premium rate phonelines. A number of Bluetooth vulnerabilities have been found in its history, however most have since been patched. A major bug in 2007 meant that a hacker could open a remote root shell on any Mac running OS X 10.4. This shell could then modify the contents of the hard drive, and reveal sensitive documents.

Ease of Use

NFC allows a fast and easy connection between two enabled devices. The lack of authentication makes a file transfer as simple as quick bump. While this opens a security hole, it means that NFC is very easy to use, and requires much less knowledge than Bluetooth. Once turned on, NFC will be automatically enabled when needed, and doesn't require any further setup. One advantage of this is that there is very minimal battery drain with NFC left on. Bluetooth can drain an excessive chunk of power even when powered off. Bluetooth requires the entry of a PIN code first, and has many settings to configure such as device name and pairings. This ultimately makes Bluetooth file transfer less intuitive than the simple bump needed with NFC, however it ensures that transfers are secure.

(Note: most file transfers initiated using NFC take place over Bluetooth - NFC has no capability to transfer data bigger than a few short instructions or a small amount such as a contact card).

Abilities

NFC transfers files at a maximum data transfer rate of 424 kbit/s, which is much slower than the theoretical 24 Mbit/s rate of Bluetooth 4.0. NFC is only suitable for small files, and Bluetooth shouldn't really be used for files over ~ 150mb. For large files, Wi-Fi Direct is recommended, which is a different matter entirely.

Bluetooth allows a connection to headsets and speakers: a feature which NFC doesn't support. This means that for people wishing to stream their music through their car speakers or headphones, Bluetooth is the only option. NFC simply lacks the range required and does not support audio streaming. Bluetooth is also used with smart watches, which display texts and other information directly on your wrist.

NFC can be used with tags. When the phone touches the tag it can activate a number of commands, which include opening an application on the phone, loading a webpage or even changing settings such as toggling Wi-Fi. This is useful as it means that 4G can be activated as you leave the house, and Wi-Fi can be turned back on when you enter, which can potentially save a lot of battery. In regards to battery life, NFC typically draws around 50mA of current when powered on. This is reduced by a couple of features baked into the Android OS:

NFC polling is limited to 10Hz, meaning the transceiver will only looks for tags at certain intervals and not consistently, which helps battery life greatly. This polling is completely disabled when the screen is turned off, which means that when your device is in standby, so is NFC. When the screen is merely locked, polling ceases but card emulation doesn't, which allows apps such as Google wallet to function.

NFC will generally consume minimal amounts of battery, with the general consensus being around 0.5% a day with no use, which wouldn't be missed. Bluetooth drain is slightly more, perhaps around 4% per day, however this is also barely noticeable in real world use.

Final words

In conclusion, I still feel that NFC has a long way to go before it will match Bluetooth, due to limited range and low file transfer speeds. It is easier to use than Bluetooth, however has limited use, only being useful for small file transfers. Bluetooth is great for streaming music to an external speaker, and for transferring files from a PC to Phone. Not many PCs have NFC, but all can be fitted with a Bluetooth dongle, and all Apple laptops have Bluetooth 4.0 inbuilt.

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HTC Desire 600 - dual SIM device review

Posted by Unknown Wednesday, September 4, 2013 0 comments

The HTC Desire was HTC's well known flagship in 2010, since then their flagship brand was replaced by the One series, however due to its successful history the Desire name is still being used for the mid to low end range releases. If you want the short version of this review: The best thing about the Desire 600 is the build quality, it's a mid-range premium phone.

A Mid-Range Premium

Shortly after the release of the One, HTC announced the Desire 600 dual sim with many of its big brother's features - mainly HTC Sense 5, Blinkfeed and Boomsound. It also includes Video Highlights, but omits the Infra Red blaster and Ultrapixel sensor (2.0µm). Instead, it's replaced with a standard 8MP BSI camera sensor (1.4µm) and the first version of the HTC ImageChip - this also means that the Zoe features are lost in the process. It joins the fleet of other HTC dual sim specialists like last year's Desire SV and One dual sim (limited to specific markets).

Design & build quality

Being mid-range doesn't prevent it from carrying HTC's renowned build quality and in fact the device has some impressive highlights: the screen is protected by a robust metallic frame which also houses the dual speaker grilles, this in turn is surrounded by a plastic bezel with a very convincing brushed metallic finish.

The black version is full black contrasted with a glossy speaker frame, matte brushed bezel and a back cover with a matte grained finish which does a very good job of resisting fingerprints. Unfortunately the back's finish feels slightly irritating to the touch and fails to provide maximum grip.

The white version on other hand has a more daring and different finish, it has the speakers' frame coated in red, the brushed bezel painted in silver and smooth glossy white plastic for the back cover.

The plastic back cover is removable: it's pretty solid but as is typical with such removable covers, it can creak under pressure. Beneath the cover cover lie two microSIM slots and a microSD slot as well as a replaceable 1860mAh battery - like everything HTC the interior has surprisingly fine fit and polish.

The camera lens and LED flash are covered by a protective glass bevelled inwards which should prevent it from collecting scratches.

The buttons have a nice, solid feel as well. The power button is at top right; volume rocker on the right hand side; and the capacitive buttons are similar to the One, with 'back' on the left, 'home' on the right and the HTC logo in between. The rest is taken care of with gestures. Finally a 3.5mm audio jack is located at top left, and the micro-USB port is on the bottom.

All in all this is a very well built device with a sharp look (especially the black version). The slim tapered edge is reminiscent of the black HTC 8x and compared to competitors' mid-range devices, the Desire 600 build quality and design are miles ahead.

Boomsound versus Boomsound

The Desires 600 sports the HTC One's star feature, dual frontal stereo speakers with built-in amplifiers. This is "only" a mid range phone so you might expect less quality, compared with its big brother: but far from it! Compared to the One flagship it's just a notch lower in loudness and noticeabley less bass. Curiously while the One sounds significantly better with beats audio, the Desire 600 actually sounds better once the default beats enhancements are disabled: leaving it enabled seems to result in a more hollow sound. With this said, the quality is still excellent for its range, beating flagship devices from opposing brands.

If you would like to know more about the HTC One's phenomenal sound quality be sure to check our post: HTC One review - part 2: Hardware

Display, 4.5" Super LCD2 at 245ppi

The screen is another quality seeker on the Desire 600: despite a qHD resolution (960x540), it's running on a 4.5" panel which results in a respectable 245ppi pixel density. The display still inherits all the other Super LCD2 merits from last year's flagship the One X (720p, 312ppi) which was lauded for its screen quality. Thanks to optical lamination it has excellent view angles and deeper blacks; there is no gap between the glass and LCD itself which makes the screen appear afloat. While not as sharp, colorful or contrasted as the One X, the screen is still significantly better than the Pentile Amoled qHD screen on last year's premium One S.

Camera, 8MP with last year's killer features

Instead of the ultrapixel (a low-light loving sensor with 2.0µm pixel size), the Desire 600 uses a standard wide angle 8MP BSI sensor with 1.4µm pixel size, but keeps the same f2.0 aperture and 28mm unique wide angle lens as the flagship. It also includes the older HTC ImageChip from last year's flagships which gives us powers like HDR, burst shooting and VideoPic (take still shots during video capture) as well as super fast shutter/focus, slow motion video and flash metering: however it loses all the fancy Zoe features, which are enabled by a newer ImageChip 2 on the HTC One. Video recording maxes out at 720p; most likely due to the lesser capabilities of the Snapdragon 200 SOC.

Daylight pictures are of good quality but slightly hurt by HTC's default aggressive digital sharpness: thankfully you can always reduce sharpness using the Image Adjustments menu in the camera app. In terms of low light it's perfectly usable when scaled down, especially indoor shots but 1:1 detail gets seriously degraded due to the smaller pixel size. Unfortunately HDR; which was flawless on last year's HTC One X; fails to do a good daylight job here (curiously it's the same issue as on the HTC One). On the other hand there is a great "HDR low light" feature in Sense 5: when used alongside the LED flash, the camera snaps two shots - one with flash and another without for mixed exposure, it gives far superior results to the washed out colors of standard LED flash photography.

HTC Sense 5 in duality

The tested device was preloaded with 1.17.707.3 firmware (Android 4.1.2) & HTC Sense 5.0. This is the same well praised UI from the full fledged HTC One; it is a known quantity by now so let's focus on the advertised features of the Desire 600, BlinkFeed, Video Highlights and dual SIM convenience.

Blinkfeed is HTC's version of Flipboard, it compiles news and posts from various sources (including your social media) in a nice scrolling layout embedded as the main home screen. You can't disable Blinkfeed - but you can set another home screen as your main one, and Blinkfeed will get moved to the right: you can also disable it further by removing newsfeed sources.

Video Highlights is a feature which automatically compiles a video reel from your photos and videos in your phone's gallery. This works based on an event's time and location (you need to select your gallery content to be sorted by events). You can choose different preset themes for different effects and music. This is all done in real time and it works surprisingly well considering the modest Snapdragon 200 SoC in this phone. If you like the end results you can then save it as an H264 MP4 video to keep or share.

The two Sense 5 features which are missing compared to the HTC One are Sense TV and HTC Zoe, which rely on the One's hardware (IR blaster and ImageChip2).

The way the dual-SIM functionality works is interesting; Sense 5 was revised with this in mind. For example, you can choose Slot 1 or Slot 2 straight from the dialler - and an improvement over the Desire SV is that you can now receive notifications about two calls at the same time... you can even answer both calls and the first one will be placed on Hold. Throughout the UI there are other optimisations to help you use both numbers without mix-ups.

One thing to keep in mind about a device in this range: while it will surely receive maintenance updates from HTC, unlike the high end phones don't expect a long term commitment regarding Android (or maybe even Sense) updates.

In terms of connectivity, only one of the two microSIM slots supports 3G/3.5G (HSPA) - the other only supports 2G/2.5G (Edge). The Desire 600 also includes GPS/GLONASS, NFC and Bluetooth 4.0 with APTX support.

Performance, a slow quad core

Here we arrive at my main niggle with this device: while it is mid-range it's still not an entry level device - and priced at around 400$ we should expect a decent performer. Unfortunately this 1.2ghz Snapdragon 200 SoC variety includes quad A5 cores and an Adreno 203 GPU along with a 1GB of DDR2 RAM. The quad will certainly assist in multitasking preventing long waits or hangs (which means it does well in certain benchmarks) but in terms of raw processing power the A5 is merely adequate and the entry level GPU is overstretched by the qHD resolution. This is why the Desire 600's UI is nowhere near as snappy or smooth as the HTC One Mini. You'll find that you can improve the smoothness of the UI by enabling "Force GPU" and "Disable HW overlays" from the hidden developers options.

For those interested here are some benchmarks and system details:

Gaming, an entry level GPU

Given the affordable price, excellent stereo speakers with built-in amplifiers and a good quality screen, you can enjoy casual gaming on this device and lighter games. Temple Run 2 ran extremely smoothly in medium graphics mode (laggy if raised to high): but heavier 3D games like Fast & Furious 6 had most graphics intact, yet with a very poor frame rate. Ripetide GP2 ran with most fancy graphics enabled but at a poor (unplayable) frame rate: however reducing the game resolution or graphics effects from the in-game settings did improve things.

In order to assess the GPU let's check the following GFXBench comparative, this is run onscreen since it reflects actual 3D gaming at the device's native screen resolution:

HTC One, T-Rex HD 15fps, Egypt HD 40fps (onscreen FHD - Adreno 320)

HTC One S, T-Rex HD 11.3fps, Egypt HD 28.4fps (onscreen qHD - Adreno 225)

HTC One Mini, T-Rex HD 9.3fps, Egypt HD 24.2fps (onscreen HD - Adreno 305)

HTC Sensation XE, T-Rex HD 5.9fps, Egypt HD 16.3fps (onscreen qHD - Adreno 220)

HTC One X, T-Rex HD 5.5fps, Egypt HD 15fps (onscreen HD - Tegra 3)

HTC Desire 500, T-Rex HD 4.7fps, Egypt HD 11.9fps (onscreen WVGA - Adreno 203)

HTC Desire 600, T-Rex HD 4.0fps, Egypt HD 10fps (onscreen qHD - Adreno 203)

HTC Sensation XL, T-Rex HD 3.1fps, Egypt HD fail (onscreen WVGA - Adreno 205)
HTC Explorer, T-Rex HD 0.9fps, Egypt HD 3.5fps (onscreen HVGA - Adreno 200)

You can clearly see the Desire 600 is around the bottom of the list: its modest GPU is over stretched by the qHD resolution. Adreno 203 seems to have been updated over the old Adreno 205, it fares better on the WVGA Desire 500, but it's nowhere near as fast as the Adreno 305 on the HTC One Mini or Galaxy S4 Mini/Duos - and the HTC One's graphics power seems like a distant dream.

Battery life

The included 1860mAh battery sounds good on paper but in practice with dual SIMs and data connections fully engaged you will be lucky if it lasts you the full day. Of course your mileage will vary but connectivity is the biggest drainer here - use with care.

Conclusion

The most impressive aspects of the HTC Desire 600 are design; build quality; sound and screen quality. There is no doubt HTC can design and build phones better than most - even if mid-range, even if plastic. Couple that with an impressive list of features thanks to HTC Sense 5, plus some unique hardware, and you have a really nice, slimmed down, affordable HTC One experience with an added dual SIM functionality: a "reason to buy" for many.

I can not but wish it had the Snapdragon 400 with dual Krait cores and Adreno 305 instead of the average SoC it's carrying, quad core or otherwise, it would have been a killer mid-ranger. Surely this must be the reason why HTC just announced the Desire 601 with Snapdragon 400 (and there are rumors of a dual sim variety).

Alternatively if you are around this budget and dual sims are not required, you can simply buy last year's flagship the HTC One X (or One X+) and update it to Sense 5: you would have an acclaimed smartphone with a vastly superior speed, screen and camera.

Hardware Summary:

+ Excellent build quality and design for the price

+ Excellent stereo speakers with built-in amplifiers

+ Good quality screen with excellent view angles

+ Dual SIM convenience with good UI integration

+ Impressive automatically generated Video Highlights in the gallery

+ Speedy camera thanks to HTC ImageChip

- Low End Snapdragon 200 SOC despite a quad core CPU

- Struggling Adreno 203 GPU for qHD resolution, limited gaming

- Slippery back cover

Have any questions or comments? Feel free to share! Also, if you like this article, please use the media sharing buttons (Twitter, G+, Facebook) below this post!

Official HTC Desire 600 dual sim Specifications:

SIZE: 134.8 x 67 x 9.26mm

WEIGHT: 130g

DISPLAY: 4.5" qHD Super LCD2

CPU SPEED

Qualcomm® Snapdragon™ 200, quad-core, 1.2GHz

PLATFORM

Android™ with HTC Sense™
HTC BlinkFeed™

ROM/RAM MEMORY

Total storage: 8GB, (available capacity varies)
Expansion card slot supports microSD™ for up to 64GB additional storage (card not included)
RAM: 1GB DDR2

NETWORK

2G/ 2.5G - GSM/GPRS/EDGE: 900/1800/1900 MHz
3G/ 3.5G - UMTS/ HSPA: 900/2100 MHz with HSDPA up to 7.2 Mbps
Dual SIM (microSIM) with ‘dual active’ support

SENSORS

Accelerometer
Proximity sensor
Ambient light sensor

CONNECTIVITY

3.5 mm stereo audio jack
NFC capable
Bluetooth® 4.0 with aptX™ enabled
Wi-Fi®: IEEE 802.11 b/g/n
DLNA® for wirelessly streaming media from the phone to a compatible TV or computer
HTC Connect

SOUND ENHANCEMENT

HTC BoomSound™
Dual frontal stereo speakers with built-in amplifiers
Studio-quality sound with Beats Audio™

CAMERA

8 MP camera with auto focus, LED flash
BSI sensor, Sensor size 1/3.2"
Dedicated HTC ImageChip
F2.0 aperture and 28 mm lens
Smart Flash: Five levels of flash automatically set by distance to subject
Front Camera: 1.6 MP with BSI sensor
720p video recording
Gallery with Video Highlights and HTC Share
Continuous shooting and VideoPic
Slow motion video recording with variable speed playback

MULTIMEDIA

Audio supported formats:
Playback: .aac, .amr, .ogg, .m4a, .mid, .mp3, .wav, .wma
Recording: .aa
Video supported formats:
Playback: .3gp, .3g2, .mp4, .wmv (Windows Media Video 9), .avi (MP4 ASP and MP3) Recording: .mp4

LOCATION

GPS/AGPS+GLONASS (for Russia & EU)
GPS/AGPS (for Asia & others)

BATTERY

Removable rechargeable Li-polymer battery
Capacity: 1860 mAh
Talk time: Up to 11.1 hours for WCDMA Up to 11.4 hours for GSM
Standby timev: Up to 577 hours for WCDMA Up to 539 hours for GSM

Pixels and Pixellation

Posted by Unknown Tuesday, September 3, 2013 0 comments

How many pixels do you need? This is a question many, many people ask and to be honest I think it's the wrong one. Let me give you a few numbers!

First of all, it's widely accepted that a monitor with more than 100 "dots per inch" or "pixels per inch" placed 18-24 inches from your face looks pretty good - with outstanding monitors at that distance having 130-170ppi. I'm also going to assume that the average monitor resolution is 1080p - that's 1920x1080 pixels in a 16:9 rectangle. This is actually quite generous but I've done that deliberately. Now when you're printing images on paper, it's generally accepted that 200ppi is "reasonably good" quality, and 300ppi is "excellent".

Full image - 2688x1520 (4 million pixels) displayed at 600 x 339

So - with a 4 million pixel image in a 16:9 arrangement, your image dimensions are going to be close to 2688x1520. If we divide that by 300ppi for printing we get a print size of 8.96" x 5.07". Call it 9" x 5" for round numbers and you're looking at an "Excellent" quality image bigger than most commercially bought prints which would be 6" x 4" or 7" x 5". Start blowing up from 9" x 5" and you're slowly going to start losing image quality. Pixellation will likely begin to occur at about 13" across. For displaying on a screen it's a completely different story: 1920 x 1080 pixels is about 2 million pixels altogether; and at the very best quality I've ever seen for myself (130ppi) that's a monitor size of 14.76" x 8.31" (about a 17" 16:9 monitor). So - if you display a 4 million pixel image on this monitor you're zoomed out so that half of the pixels in the image are never displayed. If you zoom in so that every pixel is displayed you can only see half of the image's area: but still at 130ppi you can't see individual pixels and the image quality is absolutely perfect. On my monitor at work, which is 22" 1680 x 1050 (90ppi) I begin to be able to resolve individual pixels with the naked eye when zoomed in to around 350% - where each image pixel is represented by 3.5 screen pixels on average.

So - let's use these as our ballpark figures; zoom in to 350% or print larger than 13" for individual pixels to appear on a 4 million pixel image.

The original image, cropped to 600 x 339 pixels and displayed at full size. Note the complete lack of pixellation - although there is a certain fuzziness to the detail.

Now, let's look at how the vast majority of mobile phone users use the photos they take. Please don't think of yourself or your friends here; think of the millions of people buying smartphones and how THEY use their pics. Look at Facebook, Flickr, Tumblr, Twitter, etc. That's right - MOST people - the vast majority - use the photos the way they come out. They don't edit, they don't crop, they don't zoom, they don't do any more than perhaps a bit of red-eye removal. And how are those images distributed in the main? They are very rarely displayed at their full size (in fact Facebook almost never even holds the pictures at full size but "processes" them in a way which removes massive amounts of detail and image quality to save storage space). Most places (Facebook included) allow you to choose a range of sizes to upload at, to optimise data traffic and storage space use.

The original image, cropped down to 198 x 146 pixels, and displayed at 600 x 339 to keep the playing field level with the other images. Note the fuzziness; and you can start to see individual pixels. This is now less than 9% of the original image, AND it's blown up to four times actual size.

So - the image you see on the screen is usually displayed to you at 600-1000 pixels across - far less than the original photo. At this resolution, a photo taken at 13 million pixels and a photo taken at 2 million pixels will look EXACTLY THE SAME. There is simply no way to see the original detail because making the picture that size has destroyed it - and if both are now the same width with the same scene depicted the remaining detail in the picture is also the same.

Now - there are a minority of smartphone camera users who shout "but I crop, zoom, edit my images - 4 million pixels is not enough!". I don't want to make fun of those people but - if you take a photograph so poorly that the image you want from the original picture is 30% or less of what you photographed, you're doing it wrongly. Take the photograph you want in the first place rather than taking a wider scene and then cropping it down to a postage stamp. Move closer to the subject and frame it properly. If you can't move close enough that the subject is easily visible in the frame, then a smartphone camera is the wrong tool for that image. Use a camera with a nice big lens, optical zoom and a nice big sensor. Smartphone cameras were (and are) intended for quick opportunist snaps; although a skilled photographer can capture some outstanding images with even a 4 million pixel smartphone camera because they're a skilled photographer. For examples of what I mean, look up Colby Brown who uses smartphone cameras to take many of his unbeatable images. All are displayed on his site at 1140 pixels across and yet they look absolutely fantastic regardless of the camera he used. Another up-and-coming digital photographer is Craig Fish who also uses a 4MP smartphone camera for many of his shots.

To prove my point, here are links to one image which has been progressively halved in size until the smallest one is HALF A MILLION PIXELS. I challenge you to see the loss of quality without zooming in... until you get below the resolution of your monitor.

Original image: 4 million pixels

Half Size – 2 million pixels

Quarter size: 1 million pixels

One eighth size: half a million pixels

This article is also to be found on its author personal blog.

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Cameras in Phones - what do we really need?

Posted by Unknown Monday, September 2, 2013 0 comments

An awful lot is being said about mobile phone cameras just lately; and we have HTC to thank for opening the conversation with the introduction of their HTC One which has half as many pixels at twice the size of anyone else's. Before we begin I'm going to get some ground rules. I won't use marketing terms; so I will talk about how many pixels a camera sensor has, and what size they are. You won't hear me talking about mega- or ultra- anything. Next is that I will show my meaning with diagrams - I'm a visual person and it helps me to explain. Please bear with me on this post; there's a lot to read but it's worth it at the end.

A digital camera uses a lens to focus an image onto an oblong of special material which has a number of sensors on it; each sensor is called a pixel and usually contains three sub-pixels; a red, a blue (actually two blues but don't worry about that) and a green one. Each of these sends a signal to the camera depending how much light of that colour is falling onto it. Bigger pixels produce a bigger signal for the same amount of light than smaller ones. When signals are small, the amount of noise (erroneous signal levels produced simply by electrons moving around) is a bigger percentage of the whole signal because noise is a constant backdrop. When the signals are bigger therefore, it's easier to pick out the signal, from the noise. More noise means that the signal produced by a smaller pixel is less accurate which means the final photo may not have exactly the same colour from each pixel receiving the same light.

Camera sensors line up their pixels in rows and columns - and the camera's rating is often quoted by counting them. For instance a 10MP camera contains ten million pixels (roughly). These are arranged in a rectangular grid with a side length ratio of 16:9 - so that's 4213 pixels across and 2370 pixels high. If you have a sensor which is 7mm across, each pixel is 7/4213=1.662 microns across (microns = thousandths of a millimetre).

In the real world, standard sensor sizes and pixel sizes exist; a 13 million pixel camera in a phone will have pixels about 1.1 microns across; this gives a sensor width of about 4.55mm (there are 4128 pixels across the image). In the HTC One, the best photos are 2688 pixels across, and the pixels are 2 microns across giving a sensor width of about 5.4mm.

: Figure 1 - 4 million large pixels

: Figure 2 - 8 million (smaller) pixels on same size sensor

Now we can start looking at construction. Take a look at Figure 1. This shows a camera with large pixels - the lens is focussing the image onto an area exactly the same size as the sensor. In Figure 2, we gave the camera more pixels (which really does give more detail in the image but at the expense of noise and grain - and also less sensitivity at low light levels). Of course; straight away you want more, BIGGER pixels. Figure 3 shows that if you make that happen, the image doesn't cover the whole sensor; the light falls on a little bit of it. So - in Figure 4 we move the sensor further away to ensure the image covers all the pixels.

: Figure 3 - 8 million large pixels with no other changes

: Figure 4 - Sensor moved away, but the lens size is unchanged.

However; the same amount of light, entering the lens, is now spread over a wider area: this dims the light hitting each individual pixel, which reduces the signal output and increases the noise. The only way to change this is to make the lens bigger - the aperture wider - so that more light gets in. This is shown finally in Figure 5.

: Figure 5 - all required changes incorporated.

So - how far back do we have to move the lens? Simple trig shows us the answer. Imagine the "field of view" of the lens is about 60° (not unreasonable): the light coming in from the left and right cross over in the centre of the lens and make a triangle with the sensor as the base... an equilateral triangle is formed with all angles at 60° and all sides the same length (let's call it 5.4mm to stick with the HTC One's sensor size). So the lens must be 2.7mm away from the sensor. If we now make the sensor an 8MP one (3800x2140 pixels) that gives a width of 7.6mm - the lens still has a viewing angle of 60° so that means the sensor has to be 3.8mm away from the lens. Obviously I have used 60° as the lens viewing angle because it makes the angles, sines and side lengths easy to calculate - the numbers are probably quite different in real life but you get the idea: to get double the megapixels you have to move the sensor further from the lens, which means you need a bigger lens to gather the light needed to adequately illuminate it. Lenses very rapidly increase in price with size - a lens 4mm across instead of 2mm might cost three or four times as much. (BTW - the large circular opening on the back of the phone is NOT the lens; the lens is the tiny dark speck in the centre of it).

In practical terms for a smartphone? This means that, to get an 8 million pixel camera, with pixels 2 microns across, your phone would need to be about 16-18mm thick (at least at the camera's location); and the phone would cost upwards of US$1000 - possibly even more - JUST because of the lens.

This isn't something which can be corrected with better design, or better lenses; the only way to mitigate this increase in size and cost would be to make smaller pixels which had the properties of larger ones - and that my friends is the nirvana of a pixel scientist! The very best technology available is going into these phones - and with today's tech we're stuck with these limitations. In another article I'll talk about why I believe 4MP at 2 microns across is enough.