Rivals Samsung and Apple will release the successors of their flagship smartphones this year, but which is worth waiting for.

Reports said that the iPhone 6 will include a "Super HD" screen display and camera. Speculations claimed that it is beyond the Full HD displays in HTC Droid DNA.

This notion is backed up by an analyst. According to Jefferies stock analyst Peter Misek, "the iPhone 5S/6 has a new 'super HD camera/screen, a better battery, and NFC,' and 'possible updates include an IGZO screen for Retina+, 128GB storage."

We may see two iPhone launches this year; one in second quarter of 2013 and another in third or fourth quarter of the year. This is backed by the reports that Apple is looking to switch to a 6-month cycle instead of a 1-year cycle with the iPhone to be more aggressive against competitors such as Samsung and Google.

Samsung Galaxy S4, on the other hand, may boast a massive 5-inch display which throws it right into the phablet category. It will also have a 13MP rear camera, a bigger battery and the new EXYNOS 5440 quad-core processor, which will make the device thicker.

The Samsung Galaxy S4 is pegged for release on either the second or third quarter of the year as it is planning for a head start over its rival. Samsung revealed that the much awaited smartphone will be released post May of this year.

Below is the comparison of Samsung Galaxy S4 and iPhone 6 base on the rumoured specs and features of the devices.

Screen Display - Samsung Galaxy S4 will sport 5 inches Super AMOLED touchscreen with 1080x1920 pixel resolutions. Other rumours claimed that GS4 will be equipped with flexible screen displays. Upcoming iPhone 6 is also speculated to boast 5-inch Full HD display.

Processor - Samsung Galaxy S4 is rumoured to have 8-core processor paired with 2GB RAM. iPhone 6 will probably powered by an updated A6 chip.

Operating System - Samsung Galaxy S4 is speculated to run with the upcoming version of the Android OS - Key Lime Pie or the new mobile software TIZEN OS. iPhone 6, however, will run with iOS 7.

Internal Storage - Samsung Galaxy S3's successor will have 16GB, 32GB and 64GB internal storage with additional storage through microSD slot. iPhone 6, on the other hand, will have a 128GB storage.

4G/LTE - Both devices will support 4G/LTE connectivity.

NFC - Both smartphones will be capable of Near Field Communication. iPhone 5 did not support such feature, which impedes on the sales of the device.

Camera - Samsung Galaxy S4 is rumoured to have a 13MP rear camera. The specific megapixel of iPhone 6's camera is still unknown but rumour hast it that the device will have a super HD camera.

Samsung and Apple remained mummed on the rumours surrounding their upcoming smartphones.