Transparency types and Layer transparency

[colin_e]

Increasingly, image editing applcaitions seem to be adopting at least a subset of the Photoshop set of transparency / overlay types as a standard.

In some cases this is probably just a name change, i..e.-

Mix == Normal
Dodge == Bleach (?)
Burn == Stained Glass (?)

but there are other transparency types (Hard Light, Soft Light etc.) for which I don't think Xara has equivalents. When it gets down to rendering transparency Xara is compositing pixels just like an image editing app, there doesn't seem to be any reason why Xara coudn't implement a wider set of compositing modes. The option to use PS-compatible names or Xara names (the Xara names are probably more meaningful to non-PS users in some cases) would be a nice touch.


I can also see value in adding layer transparency and layer-level overlay modes. I'm not talking here about starting to break down Xara's object-oriented approach to drawing and going the way of Photoshop's "everything needs it's own layer" style.

However there are times when you do need everything on one layer to have a particular transparency style (transparent overlays for sketching/tracing for example), and it's slightly more convoluted to have to select the layer, group the contents, and then set everything ON the layer to a common value of opacity and overlay mode.

There are some crcumstances where the aboev simply wouldn't work (e.g. if the objects on the layer are already combined using transparency, but you need the whole resulting layer to have a distinct tranparency type of its own).

What do people think, can value in this?

Regards: colin_e

[gwpriester]

Actually Bleach is additive transparency and Stained Glass is subtractive transparency (this might be the other way around). Dodge and Burn are derived from the old darkroom print making technique of darkening and lightening parts of a photo. This often involved passing an object over parts of the film to block the image being projected onto the photo paper.

[Soquili]

Hi Colin,

In Photoshop the use of layers are actually blending modes rather than types of transparency. Some of the Xara transparencies can achive a similar effect as a Photoshop blending of layers but not all.

In Photoshop a "Normal" blending of colours can be achieved using a "Mix" transparency within Xara.

In Photoshop the "Dodge" blending mode reduces the simulated amount of exposure a "Photographic Print" receives from the enlarger. In Xara a Blench and/or Lighten transparency can be used for a similar effect.

The Stained Glass transparency may be perceived as being similar to the Burn blending mode within Photoshop but is subtly different. Stained Glass effectively ignores pure white areas of the object that has the transparency so they do not effect the object that is beneath the transparent object. Darker portions of the transparency object progressively interact with the object beneath.

The Hard Light and Soft Light effects are not directly related to and of Xara's transparency types.

[colin_e]

I would say whether you call these "blending modes" or "transparency types" is simply a matter of terminology. They are all mathematical and/or logical processes at the pixel level for generating a result by combining an image "on top" with an image below. I.e. compositing.

I suggested the option of having PhotoShop-compatible names available as a convenience to anyone coming from either Adobe apps directly, or one of the many others that uses Adobe-style naming. I'm aware that some of the Adobe names are historically related to traditional wet photography and are now rather anachronistic. I'm not suggesting the Adobe names are "better", just more familiar to some users.

What i'm really interested in however is not the names, it's the available modes (transparency types). Xara implements quite a small set. I don't think many people probably use the full set of something like 27 blend modes (!) that PS CS5 apparently offers, but I do find myself missing some.

For example, in the old copy of Micrografx Picture Publisher that was my default image editor for years, a great way to achieve the "soft glow" that portrait photographers love (great for minimising wrinkles!) was to-

* Duplicate the base image as a new layer (PP used objects, but the idea is the same).
* Gaussian-blur the upper (duplicate) layer.
* Set the blend mode to "if lighter".

This is an example of a logical blend mode (show the colour of the upper layer if it is lighter than the lower layer, otherwise show the lower layer). I don't think there is a direct equivalent in Xara.

What it achieves in this case is the softening of highlights without any corresponding deepening of shadows, giving that slightly dream-like (and very flattering) glow beloved of photographers. As noted it works particularly well on portraits. While I know Xara ian't an image editor per se. I find myself using it a lot for "assembling" groups and montages of images (e.g scrapbooks), because Xara is just so damn fast and easy to use for this type of work that combines images, text, and drawn content, that it makes most image editors feel painfully awkard by comparison.

I have no doubt that given more blend modes the outstanding artists here on TG would find new ways of using them.

Regards: Colin

[handrawn]

you cannot blend in a vector editor the way you can in a raster editor - this is not because no one has got round to it - it's because they don't work the same way

this is one of the reasons that xara has a shortcut for directly editing in a pixel editor such as PS and returning the result directly back to xara without having to open said pixel editor separately

[itsfransie]

If it is just a matter of raster vs. vector, then perhaps this could be done through a new kind of live effect?

[PhilM]

Don't forget the new Enhance transparency type introduced in V6 Pro which allows arbitrary patches to apply blur,sharpen, brightness, contrast and hue filtering to whatever is underneath them. The photo tool is the main UI for applying this but it is possible to apply it directly in the transparency tool (I think).

This is a raster effect being applied in a live, vector way.

Phil

[Boy]

Thanks for pointing this out, Phil. I didn't know about it yet. To use it (including in mask mode for bitmaps), I found the help file(Help/xxx Help/Contents/Transparency/Enhance) very useful.

[itsfransie]

Don't forget the new Enhance transparency type introduced in V6 Pro which allows arbitrary patches to apply blur,sharpen, brightness, contrast and hue filtering to whatever is underneath them. The photo tool is the main UI for applying this but it is possible to apply it directly in the transparency tool (I think).

This is a raster effect being applied in a live, vector way.

Phil

Blur/sharpen only works on photos and on mask shapes applied to a photo. It would be very nice if this limitation could be removed.

[spline]

I agree that the names of the modes are industry standard today, and Xara is one of the few not using the standard names, making it more confusing for most people to switch to Xara. (more to learn and slower to work with)
It would also be nice with layer blending modes if possible since its such a quick way to change things.

And it should be possible since both Inkscape and Flash can do this.