Filters
This page is a stub. Full content might come eventually.
Unfiltered images for comparison.
General filters
These filters may be available on for multiple layers or panels.
Rotation
Colour correction
Filters ►
Subject ►
Colour correction
Filters ►
Palette ►
Colour correction
Filters ►
Canvas ►
Colour correction
Colour correction is explained in tutorial-1-4.
Subject specific filters
Smart blur
Filters ►
Subject ►
Smart blur
The effect is subtle and varies with the size and type of the subject but it can make a big difference to the complexity of the paint areas and their outlines.
Oil filter
Filters ►
Subject ►
Oil filter…
This filter produces an oil painting effect. It is useful in reducing texture detail and smoothing the outlines of paint areas.
Saturation
Filters ►
Subject ►
Saturation…
We can supply a saturation value from 0 to 100. The default value is 1.0 for no change.
Brightness
Filters ►
Subject ►
Brightness…
We can supply a brightness multiplier value from 0 to 3.0. The default value is 1.0 for no change.
Contrast enhancement
This filter stretches each of the red green and blue channels to use the full range available.
Unsharp mask
Posterization
Subject ► Warp
A sub-menu. Not released yet (but high-up on the list) (-enableassertions).
Filters ►
Subject ►
Warp ►
Schaefer warp
Filters ►
Subject ►
Warp ►
Perform subject warp
Filters ►
Subject ►
Warp ►
Define incremental subject warp points
Filters ►
Subject ►
Warp ►
Perform incremental subject warp
Filters ►
Subject ►
Warp ►
Define bulge subject warp points
Filters ►
Subject ►
Warp ►
Revert subject warp
These controls will allow us work from our own drawings rather than tracing the subject image and still be able to line up the canvas images so we can compare the colours to the subject. We will be able to do our own a free-hand drawing and then, as a one time task, warp the subject to match the it and create aligment markers so that subsequent canvas alignments will work.
Canvas specific filters
Other filters
Sketch filter
Filters ►
Subject ►
Sketch configuration…
This is technically a subject filter but the result is written to its own
sKetch layer
rather than the filtered Subject layer
which is why it's in the Other filters
sub-menu.
Selecting this item will cause the sketch configuration dialog to be displayed.
The contrast multiplier value controls how high contrast the sketch is,
that is the lighter values are pushed even lighter and the darker values darker.
The contrast centre value controls where the centre of this contrast push is.
The further a value is from the centre the more extreme the enhancement.
If it's near the middle the the lightest and darkest values will be made extreme.
If it's near the top the light values will remain largely unchanged but any darker values,
which will be most of them, will be made even darker.
We should probably aim for much less detail than we think we'll need. The sketch is only there to give us a broad placement map of the larger objects in the scene.
Lighting correction
This filter can be used to alleviate lighting problems on the canvas or palette. It is always better to correct the lighting rather than use this filter. This is provided for very large paintings where that may not be possible. It is a simple linear correction and will not cure vignetting or other complex lighting problems.
The image must be currently loaded as the canvas, palette or subject. It should not have had any other filters already applied and should not have any associated palette entries to start with.
There needs to be two widely separated areas that should be the same colour, but aren't. Perhaps you can use the backing board on an easel which is larger than the canvas. It may be that we need to place sheets of card as targets before taking the photo. They should be on opposite sides of the photo in the direction of the lighting problem so they a appear to be different colours even though they're not.
Make selections in these areas to create palette entries. They should be the only two entries for this image.
Select them and then do:
A linear colour grading is applied to the image. The two selected areas are re-sampled and hopefully have become more similar colours. If they have become the same colour only one entry will be shown.
The palette entries are re-sampled at the end and should then be the same colour (ish). It is usual to delete these entries afterwards.
This filter doesn't have an undo so you should save the project before you apply it.
