Looking at 1080i and 1080p HD TVs
1080p (p means progressive) or Full HD TV as it is also known is the best screen format of high definition television.
It is a common misconception that 1080p signals are not widely available and that for smaller screen sizes (only for big screens), 1080p provides little or no benefits.
This however is not the case.
The fact that the resolution of 1080i and 1080p is 1920 x 1080 pixels per raster also goes to disprove another popular misconception that the progressive format has a better resolution than the interlaced format.
To clarify this both have 1080 horizontal lines on which there are 1920 pixels.
To best understand the basic difference of progressive and interlaced scanning we must talk about both methods in relation to time.
Native 1080i HD TVs have a sample rate of 60hz meaning that the image on screen is updated 60 times for every second.
When using the interlaced scanning method only half the 1080 rows of pixels are refreshed on each sample, only alternate rows are refreshed and so it takes two cycles to refresh all rows.
Because of using alternate rows of an image when required to display movement, the interlaced scanning method produces blurring or jitter because the lines do not match.
1080i televisions are better at displaying images that have little or no movement as the jitter is less noticeable.
The 1080p method is different in that is does not sample or refresh alternate lines it refreshes all 1080 line 60 times per second.
How can using 1080p effect and improve the 1080i signal that is being input in to it? When a 1080p television has a 1080i signal input into it is does something called de interlacing with the signal.
To explain this, the parts of the pictures that contain movement on screen are interpolated and the areas that are without movement are combined together.
The outcome of all this is the images displayed has loss of detail in the parts that are moving and the still parts do not.
It is a common misconception that 1080p signals are not widely available and that for smaller screen sizes (only for big screens), 1080p provides little or no benefits.
This however is not the case.
The fact that the resolution of 1080i and 1080p is 1920 x 1080 pixels per raster also goes to disprove another popular misconception that the progressive format has a better resolution than the interlaced format.
To clarify this both have 1080 horizontal lines on which there are 1920 pixels.
To best understand the basic difference of progressive and interlaced scanning we must talk about both methods in relation to time.
Native 1080i HD TVs have a sample rate of 60hz meaning that the image on screen is updated 60 times for every second.
When using the interlaced scanning method only half the 1080 rows of pixels are refreshed on each sample, only alternate rows are refreshed and so it takes two cycles to refresh all rows.
Because of using alternate rows of an image when required to display movement, the interlaced scanning method produces blurring or jitter because the lines do not match.
1080i televisions are better at displaying images that have little or no movement as the jitter is less noticeable.
The 1080p method is different in that is does not sample or refresh alternate lines it refreshes all 1080 line 60 times per second.
How can using 1080p effect and improve the 1080i signal that is being input in to it? When a 1080p television has a 1080i signal input into it is does something called de interlacing with the signal.
To explain this, the parts of the pictures that contain movement on screen are interpolated and the areas that are without movement are combined together.
The outcome of all this is the images displayed has loss of detail in the parts that are moving and the still parts do not.