Bview offers the possibility to manage your media color by using simple features :
- Apply a color space
- Apply a LUT
- Manage the gamma and brightness
In addition to this, two other advanced features are available : LUT and CDL.
In image processing, a lookup table (also known as LUT) is used to transform the input data into a more desirable output format.
How to use
At the moment, only .3dl (Autodesk) file can be used for LUTs.
It can be loaded at Bview start using the command :
bview -luts file_name
You can also use a config file (regular text file) which contains a list of LUTs to load them altogether.
The config file must contain one or several lines with the following syntax : lut_label=path/file_name.3dl(INPUT_COLOR_SPACE;OUTPUT_COLOR_SPACE)
LUT1=/work/LUT/lut1.3dl(CINEON;SRGB) #lut_label = LUT1 #path = /work/LUT/ #file_name = lut1.3dl #INPUT_COLOR_SPACE = CINEON #OUTPUT_COLOR_SPACE = SRGB
You can add comments by starting a line with #.
INPUT_COLORSPACE / OUTPUT_COLORSPACE supported values : LINEAR, CINEON, SRGB, REC709, PANALOG, REDLOG and LOGC.
If you have a LUTs library it is also possible to load multiple files at the same time. For instance you simply need to set up a file containing the needed LUTs.
Example : file is named all_luts.txt
Now, load the file :
bview -luts all_luts.txt
In Bview, press F12 to open options panel then go to tab LUTs. All specified LUTs are displayed.
How to use with Bview interface
LUTs are also manageable directly in the options panel (F12).
- LOAD : add a lut to your project (specify path, label, input and ouput color space).
- EDIT : edit an existing lut.
- DELETE : delete an existing lut.
You can apply a global LUT (from top toolbar) or use Display LUT from the media panel to set up a specific LUT for your module. The Display LUT always overrides a global LUT.
LUTs are saved in the project (.bv). They are not permanently stored in Bview.
The American Society of Cinematographers Color Decision List (ASC CDL) is a format for the exchange of basic primary color grading information between equipment and software from different manufacturers. The format defines the math for three functions: Slope, Offset and Power. Each function uses a number for the red, green, and blue color channels for a total of nine numbers comprising a single color decision. A tenth number, Saturation, specified in the Version 1.2 release, applies to the R, G, and B color channels in combination.
How to use
A CDL is an .xml usually saved under .cc, .ccc or .cdl.
You can create your own CDL file and then load it into Bview.
Exampe of .ccc :
As for LUTs, CDLs are also managed from the options panel (F12). A text file listing multiple CDLs can also be use the same way.
You can either create them from scratch by setting a path and file name with the parameters or load existing files.
Contrary to LUTs, CDLs can be applied on a module and a sequence or movie :
CDLs are saved in the project (.bv). They are not permanently stored in Bview.
When a sequence or movie has no CDL applied but the module has, color correction from module is applied.