Among the common video resolutions, you would have heard of are 1080p, 1080i, 720p, and even 480p.
What about 576i resolution? What video resolution is this and where is it used?
To understand 576i, let’s take a look at analog TV and video standards.
They differ when it comes to the number of lines in a single frame and frame rate (how many frames are displayed per second).
576i Digital Version of PAL
576i is the digital version of the PAL analog signal. In digital terms, it’s called an SD (Standard Definition) signal.
576i resolution in pixels
The pixel count for 576i is 720 x 576.
This PAL standard is set by the Society of Motion Pictures and Television Engineers (SMPTE),
SMPTE-259-B defines a PAL signal as one that has 576 active interlaced lines.
What is 576i resolution?
As explained above 576i offers 576 lines of vertical resolution and up to a maximum of 720 lines of horizontal resolution (720 x 576).
In NTSC broadcast system countries like the USA, this is referred to as 480i (720 x 480).
What this means is there are 576 active scan lines per interlaced frame.
The frame rate is set at 25Hz to be compatible with the timing of PAL.
576i is often referred to as 576i/25. In other words, it’s 576 lines high and interlaced at 25fps.
Popularly, however, it is referred to as 576i/50, 50 being the field rate. The field rate tallies that of the electrical frequency of the country. There are two fields for every interlaced frame.
Most of the time the frame rate 576i/25 and the field rate 576i/50 aren’t indicated and are written as 576i.
Now that you have an understanding of 576i, let’s compare it with some popular video resolutions.
576i vs 576p
576p has 576 vertical lines in progressive mode. The horizontal lines range from 768 or 1024, depending on the video aspect ratio. It is a standard definition video standard for PAL TV broadcast.
Standard 576p is known as 576p/25. That’s 576p at 25 frames per second.
576p/50 has a frame rate of 50. It is the resolution of EDTV or Enhanced-Definition TV. In certain countries like Australia, it is categorized as HD resolution.
At least two Australian TV stations had used 576p before switching to 1080i.
576i vs 480i
The pixel count for NTSC is 720 x 480 also known as 480i a standard set by the Society of Motion Pictures and Television Engineers.
SMPTE-259-A refers to an NTSC signal as one that has 480 active interlaced lines.
This digital version of NTSC is written as 480i/60, which means it has 480 vertical lines with a field rate of 60.
576i vs 480p
480p is a standard-definition video with a pixel count of 640 x 480 with an aspect ratio of 4:3. This is a minimum of 640 horizontal lines and 480 vertical lines in progressive mode as opposed to the NTSC TV format of 480 interlaced lines in vertical mode (480i).
There are various 480p resolutions with the horizontal resolution changing with the vertical resolution remaining fixed. The horizontal resolution changes for different aspect ratios.
You would have come across a YouTube video with 480p resolution which has a pixel count of 854×480.
576i vs 720p
720p has a pixel count of 1280 x 720. It is often referred to as standard HD or in TVs as HD ready. It has an aspect ratio of 16: 9 as opposed to 576i’s 4: 3.
Learn more about 720p video.
576i vs 1080i
1080i’s pixel count is 1920 x 540. This is interlaced video with 1920 horizontal lines and 540 vertical pixels.
This is the preferred HD broadcast format in many countries. When you see an HD watermark on any TV program, it is either broadcast in 1080i or 720p.
Read more about 1080i.
576i vs 1080p
1080p is known as Full HD. It has a pixel count of 1920 x 1080 in progressive mode.
It gives you a total of 2,073,600 pixels on your TV screen. 1080p is also the resolution of standard Blu-ray.
Read more about 1080p.