9
votes
Accepted
Leaving white balance for post-processing. Is it a bad idea?
Don't do white balance in post, you will regret it. The problem is that the footage your camera records is compressed. That means the sensor information is not stored in RAW, but encoded using lossy ...
- 5,412
6
votes
Accepted
ffmpeg: white padding is light grey but not white
The end of the filter chain should output full RGB, like this:
Windows batch:
ffmpeg.exe -i "https://gooseberry.blender.org/wp-content/uploads/2014/01/franck.jpg" ^
-filter_complex ^
scale=iw*...
- 32.7k
5
votes
How to color grade gold
Two thoughts:
Go to images.google.com and search for "gold". Find something you think is gold-colored, check its RGB values, and then use that as a target for your gold. Many editing programs have ...
- 4,730
5
votes
What is the colour range of most videos?
Most videos are limited range i.e. luma goes from 16 to 235, and chroma from 16 to 240.
Unless expressly set, FFmpeg does not scale the range from one to another. Whatever the source is, that's the ...
- 32.7k
4
votes
Accepted
Why are there so many color spaces available?
There are a number of reasons why there are so many color spaces:
Color resolution - sRGB and similar color spaces only cover a portion of the visible spectrum. This means that they can be ...
- 2,156
3
votes
Accepted
Is wide-gamut video primarily an increase in saturation (for the layperson)?
Wide Gamut color space is primarily just an expanded color space that is capable of covering a larger range of values in the visible color spectrum. This, compared to sRGB and Adobe RGB.
The gamma ...
- 2,477
3
votes
Software used for Film Colourization
From the youtube video description you linked:
The in-house developed and customized cutting edge software tools
provide better image quality and colors very close to the original.
- 19.3k
3
votes
Accepted
ffmpeg bgr vs rgb and other similiar pixel formats
The order of the components in RGB32 seems to do with endianness:
PIX_FMT_RGB32 is handled in an endian-specific manner. An RGBA color
is put together as: (A << 24) | (R << 16) | (G &...
- 32.7k
3
votes
ffmpeg bgr vs rgb and other similiar pixel formats
While I always guessed that the big / little endian was more a matter of patents rather than performance,
Nope little endian was developed as a performance optimization whern moving to multi byte ...
- 1,060
3
votes
Accepted
Color correct to compensate for low blue
I am not very certain that I understand your question, but if you want to shift the color-grade of your image away from the orange, you can use the temperature to shift it towards blue, effectively ...
- 2,675
2
votes
Accepted
How can I generate a color-correct h264/MP4 from a DPX sequence using ffmpeg?
I followed up on the yuv420p(tv, bt709) portion of the encoding and discovered that this refers to the Rec. 709 colorspace for HDTV. In ffmpeg, colorspace is defined by the colormatrix filter. However,...
- 355
2
votes
Accepted
How to change every black pixel to a special color?
You can use the LUT or GEQ filters for this.
e.g. with LUT
ffmpeg -i myVideo.avi
-vf
"yadif,format=rgb24,
lutrgb=r='if(eq(val,0),3,val)':g='if(eq(val,0),3,val)':b='if(eq(val,0)...
- 32.7k
2
votes
Software used for Film Colourization
When colorizing film, filmmaker's will use a variety of commercial and custom developed tools. That mix of tools is often treated as proprietary information and is not widely discussed. For example, ...
- 2,405
2
votes
How to read 10-bit RGB values from HDR video?
The ProRes input will have YUV encoding, not RGB. If you need a raw dump, save as rawvideo.
ffmpeg -i in.mov -f rawvideo raw.yuv
Note that bit depths which aren't multiples of 8 are still stored in ...
- 32.7k
2
votes
Accepted
Why a color grading suite needs high CRI lamps?
The truth is that you do not need them... unless you do of course.
You only need good CRI for the ambient lamps if you need to compare colors with real-life things, probably the skin tone of someone, ...
- 1,152
2
votes
Manual white-balance for non-neutral lighting
You're doing it wrong. For one, the 18% grey card is for exposure, use a white card for white balance. For two, the whole point of the white / grey card is that you expose it under the lighting ...
- 13.7k
2
votes
Should color grading be performed on raw clips, or final sequence?
Grading multiple clips in Premiere is still a bit fiddly compared to something like DaVinci Resolve. If it was only three clips, I would do the grade on one clip, then copy and paste the Lumetri ...
- 7,585
2
votes
How do I get a totally consistent white tabletop background?
That's interesting. Just tried it with locked AF/AE in the camera app as you showed, and it definitely is adjusting the white background even though the focus and exposure are supposed to be locked. ...
- 7,585
1
vote
Accepted
Histogram measurement in single spot
Using ffmpeg, a free command-line tool, you can do
ffmpeg -i in.mp4 -vf "crop=1:1:234:541:exact=1,tile=50x10,format=rgb24,histogram" out.png
A series of filters are run on the input video.
The crop ...
- 32.7k
1
vote
Histogram measurement in single spot
The first thing I'd be looking at is Processing. There's a library that lets you read video, there's an example here that shows how to to sequentially grab frames from a video.
Then (instead of ...
- 13.7k
1
vote
How to clean up old animated footage?
The artifacts are on the original footage because a DVD used some oldie MP2 codec, you need to live with it.
You could try using a denoiser, some of them can detect compression artifacts. I am not ...
- 1,152
1
vote
Accepted
Why would an ENG camera need 422 Chroma?
As far as I understand, before broadcasting, your signal will be converted and changed which leads to further loss. So by providing 422, the broadcasting company has more leeway to convert/compress.
...
- 1,071
1
vote
Accepted
What is the file size difference between 8 bit and 10 bit raw video?
Instead of 8 bits per every channel and per every pixel you need 10 bits, which is 25 % increase of the raw footage.
Since the size of 8-bit raw footage is as such huge enough, 25 % of it is high ...
- 1,494
1
vote
Accepted
Difference between 10bit 4:2:2 and 10bit display panels
The bit depth and the sub-sampling method are related but different parameters of the imaging system. As you noted, the bit depth determines how many different colors the system can display. The more ...
- 2,405
1
vote
How to post-process an image to turn trees blue and a face yellow?
There are multiple things going on between the before and after image. The first aspect is a color space conversion. The original image is recorded in a "log" color space.
A log, or logarithmic, ...
- 19.3k
1
vote
Premiere Pro CS6: how to change color of a clip as time progresses?
There are several ways to do this. The basic idea is always the same: You overlay a color and then animate it's hue. To get rid of all other color, you can either convert the footage to black-and-...
- 5,412
1
vote
Why is YouTube and VLC making a slight but noticeable mess of my video background?
This is a problem that drove me crazy...
Long story short; certain browsers; whether it's Chrome, Explorer, Firefox, etc, actually handle color profiles, embedded within the video file (such as color ...
- 2,477
1
vote
What is the difference between RGB and RGB + Alpha?
The alpha channel is a grayscale 2D image plane of the same size as the RGB image, and is used when overlaying (or blending) the image on top of another image. If the value of an alpha pixel is zero, ...
- 32.7k
1
vote
Dark Video/Gama Shift from Davinci Resolve to YouTube
The MOV you exported from Resolve is tagged as Rec 601 (despite being UHD).
So, I transcoded your MOV using the command below, preserving all color characteristics and uploaded that to Youtube. ...
- 32.7k
1
vote
Graphics card and video codecs: are colors stored in a linear scale?
The correctness of this statement depends on the color model. The statement will typically be correct for color models such as RGB and CMY. In HSx (HSV, HSL) color models the model doesn't store ...
- 496
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