Explanation Series on Recent Resolution Independence Announcement – Part I. Color depth
Our recent press announcement, TMM, Inc. Demonstrates TRUDEF™ Resolution Independent Fractal Video in 4K at NAB Show, have left some our readers and supporters asking, what do those technical improvements actually mean? How do these improvements benefit TRUDEF™ users – the digital video production community?
To answer those questions, we will be posting several upcoming TRUDEF™ Blog posts that will discuss how the TRUDEF™ resolution independence improvements can enable consumers to experience a higher quality video further into the distribution chain then other compression codecs.
TRUDEF™ development will support 10, 12 and 16 bit color depths
Without getting too technical, to understand the significance of TRUDEF™ video compression being able to support 10, 12 and 16-bit color depth, we would need to explain what color depth means in the digital video industry.
What are Color depths (also known as bit depths)?
In the digital video industry, color depth or bit depth is the number of bits used to represent the color of a single pixel in a bitmapped image or video frame buffer. This concept is also known as bits per pixel (bpp), particularly when specified along with the number of bits used. In general, the bit depth determines the number of colors that can be displayed at one time. Higher color depth gives a broader range of distinct color palette.
So the Per Channel information looks like this
1 bit = 2 colors ( black or white)
2 bits = 4 color (first gray-scale)
3 bits = 8 colors
4 bits = 16 colors
8 bits = 256 colors
10 bits = 1024 colors
12 bits = 4096 color
16 bits = 65,536 colors
In an 8-bit image, each channel can hold 28 or 256 tones (shades). If we were to use an RGB model ( read here if you are interested in learning about RGB model ), where each Red, Green and Blue represents one channel, the number of colors combination that can be discern from an 8 bit RGB model image would be Red (256 shades) X Green (256 shades) X Blue (256 shades) = 16,777,216 possible color tones per pixel.
Examples – images with various bit depth (source: wikimedia)
1 bit (2 colors)
2 bits (4 colors)
4 bits (16 colors)
8 bits (256 colors)
16 bits (65,536 colors)
Here is a great video from Createasphere’s Youtube channel that can further explain color depths.
What does this mean to the digital video production community?
In general, the more bit depth a camera can output and be maintained through post-production, the more realistic and cinematic the viewing experience will be for the audience.
The higher bit depth gives post-production personnel more room to correct and/or enhance the content to meet the director’s vision. By starting with a higher color bit depth, the less information you lose from one-step to another in the digital video production workflow pipeline
The downside to choosing to work with a higher bit depth is that it takes more storage space and more time to process.
Why is TRUDEF™ support of 10, 12 & 16 bits color depth significant?
If the original source content (example: Raw footages) are in 10, 12, or 16 bits color depth, the “users” of TRUDEF™ fractal compression technology will have the ability to either use the original bit color depth or to downgrade the color depth in order to save on storage space and processing time. Present forms of video scaling are performed after decompression on colors that have been “degraded”.
If a RAW video with original 16 bpp was to pass through TRUDEF™ compression technology, the “user” have the option of either downgrading the bit depth to 10 bpp or 12 bpp. However, if the original RAW video was only 10 bpp then TRUDEF™ fractal compression technology can output at the original 10 bpp or a lower bbp, but cannot be upgraded to a higher bbp.
We hope that this give you a general overview on the concept of color bit depth and the color bit depth improvements we have made in the development of the TRUDEF™ video compression codec.
If you are interested in reading more on color bit depth, here is a great article titled 8-Bit is Still 8-Bit, Why DSLRs Are No Match for the 12-Bit Blackmagic Cinema Camera, that demonstrates the importance of how having higher bit depth affects video quality.
TRUDEF™ BLOG – http://trudefblog.us
TMMI is a technology company headquartered in the US, specializing in video image management and compression. Founded in 1990, the company is dedicated to improving bandwidth utilization and video image quality. TMMI develops digital video compression technology that provides end-to-end workflow and distribution solutions for cinema, sports, mobile, streaming media, cable, medical imaging, security, defense, space exploration and education. TRUDEF™ fractal technology offers users enhanced image quality, reduced bandwidth utilization and digital media storage requirements.