title: BloomCImg
media types:
Video experimental
description: Apply a Bloom filter (Kawase 2004) that sums multiple blur filters of different radii,
resulting in a larger but sharper glare than a simple blur.
It is similar to applying 'Count' separate Blur filters to the same input image with sizes 'Size', 'Size''Ratio', 'Size''Ratio'^2, etc., and averaging the results.
The blur radii follow a geometric progression (of common ratio 2 in the original implementation, bloomRatio in this implementation), and a total of bloomCount blur kernels are summed up (bloomCount=5 in the original implementation, and the kernels are Gaussian).
The blur filter can be a quasi-Gaussian, a Gaussian, a box, a triangle or a quadratic filter.
Ref.: Masaki Kawase, "Practical Implementation of High Dynamic Range Rendering", GDC 2004.
Uses the 'vanvliet' and 'deriche' functions from the CImg library.
CImg is a free, open-source library distributed under the CeCILL-C (close to the GNU LGPL) or CeCILL (compatible with the GNU GPL) licenses. It can be used in commercial applications (see http://cimg.eu).
version: 2
creator: mr.fantastic mrfantastic@firemail.cc
license: GPLv2
URL: https://openeffects.org/
title: R
description:
Process red component.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: G
description:
Process green component.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: B
description:
Process blue component.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: A
description:
Process alpha component.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: Size
description:
Size (diameter) of the filter kernel, in pixel units (>=0). The standard deviation of the corresponding Gaussian is size/2.4. No filter is applied if size < 1.2.
type: rect
readonly: no
required: no
animation: yes
minimum: 0
maximum: 100
default: 0 0
widget: size
title: Uniform
description:
Apply the same amount of blur on X and Y.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: Ratio
description:
Ratio between successive kernel sizes of the bloom filter. A ratio of 1 gives no Bloom effect, just the original blur. A higher ratio gives a blur kernel with a heavier tail. The original implementation uses a value of 2.
type: float
readonly: no
required: no
animation: yes
minimum: 1
maximum: 4
default: 2
title: Count
description:
Number of blur kernels of the bloom filter. The original implementation uses a value of 5. Higher values give a wider of heavier tail (the size of the largest blur kernel is 2**bloomCount * size). A count of 1 is just the original blur.
type: integer
readonly: no
required: no
animation: yes
minimum: 1
maximum: 10
default: 5
title: Border Conditions
description:
Specifies how pixel values are computed out of the image domain. This mostly affects values at the boundary of the image. If the image represents intensities, Nearest (Neumann) conditions should be used. If the image represents gradients or derivatives, Black (Dirichlet) boundary conditions should be used.
type: string
readonly: no
required: no
animation: yes
default: Nearest
values:
title: Filter
description:
Bluring filter. The quasi-Gaussian filter should be appropriate in most cases. The Gaussian filter is more isotropic (its impulse response has rotational symmetry), but slower.
type: string
readonly: no
required: no
animation: yes
default: Quasi-Gaussian
values:
title: Expand RoD
description:
Expand the source region of definition by 1.5size (3.6sigma).
type: boolean
readonly: no
required: no
animation: yes
default: 0
title: Alpha Threshold
description:
If this value is non-zero, any alpha value below this is set to zero. This is only useful for IIR filters (Gaussian and Quasi-Gaussian), which may produce alpha values very close to zero due to arithmetic precision. Remind that, in theory, a black image with a single white pixel should produce non-zero values everywhere, but a few VFX tricks rely on the fact that alpha should be zero far from the alpha edges (e.g. the premult-blur-unpremult trick to fill holes)). A threshold value of 0.003 is reasonable, and values between 0.001 and 0.01 are usually enough to remove these artifacts.
type: float
readonly: no
required: no
animation: yes
minimum: 0
maximum: 1
default: 0
title: (Un)premult
description:
Divide the image by the alpha channel before processing, and re-multiply it afterwards. Use if the input images are premultiplied.
type: boolean
readonly: no
required: no
animation: yes
title: Invert Mask
description:
When checked, the effect is fully applied where the mask is 0.
type: boolean
readonly: no
required: no
animation: yes
title: Mix
description:
Mix factor between the original and the transformed image.
type: float
readonly: no
required: no
animation: yes
minimum: 0
maximum: 1
default: 1
title: Top-Left Origin
description:
Set to 1 to use MLT top-left image origin instead of the OFX bottom-left origin. Use for plugins that crash or produce incorrect output with negative row bytes.
type: boolean
readonly: no
required: no
minimum: 0
maximum: 1
default: 0
widget: checkbox
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