smadell

What happens when an irresistible force is applied to an immovable object? Unfortunately, this is the game we are playing. I mean no disrespect, but it seems to me that you are inventing facts in support of a foregone conclusion. Nevertheless, I am done. I know that I cannot convince you with my interpretation, and it should be clear that you cannot convince me. I am OK with that. But, this debate is officially over.

It is becoming clear that you believe the phrase "partially selected pixel" is an oxymoron. This is conflating the area of the pixel with the degree of its selection. While the entire area of a pixel can be selected, that selection can also be less than full strength. Both can be true at the same time. If you don't believe that a pixel can be "partially selected," then you place yourself at odds with Serif, Adobe, and virtually all other photo software companies who quite freely use this phrase to explain the selection process.

So, @R C-R – I will amend my previous post a little, because I still believe we both understand how to get from Point A to Point B and we're just explaining it (to ourselves and others) in different ways. Once I create a selection, I have inserted certain values into the Pixel Selection channel. Those values can be anything from 0 to 1 (or 0 to 255, in 8-bit parlance). When I use that selection to create a mask (as an example) the mask reflects the selection in the sense that selected areas within that mask are black, white, or grey depending on the state of the selection. Since multiplication is commutative, it is always the case that (A * B) is the same as (B * A). So, it really doesn't matter too much if the mask is applied to the selection, or the selection is applied to the mask. The result is always the same, since (Mask * Selection) is the same as (Selection * Mask). You can understand this in any way you like, and any way that makes the most sense to you. But I think we're still seeing the same basic process going on. And, I think we both know how to get the result we anticipate.

You're putting the cart before the horse. It is indeed the selection that varies in strength. This should be obvious when you inspect the Pixel Selection channel. Also, assuming that there is an active selection, an activity such as creating a Mask or Adjustment Layer means that the selection is applied to the Mask (for example), not that the Mask is applied to the selection. This might seem like a trivial distinction, but it is crucial to understanding the way channels work. Channels are multipliers. When displaying a color, Affinity will put up a color that is G(128) when the Green channel is 50% grey for that corresponding pixel. Basically, it uses the multiplication (Green * 0.5). If my Mask is 80% grey, then the pixels being displayed are (Full Transparency * 0.8). And, if I use a Selection whose Pixel Selection channel contains pixels that are, for example, 30% grey, then the action subsequently performed on those pixels takes the general form: (Action * 0.3).

@R C-R I think we're arguing semantics here. I am using the term "partially selected" because that is the term that Serif uses, and it is the one that is generally used amongst most photo editing programs. In that sense, "partial" selection implies two things: (1) the entire pixel is selected, since as you correctly note – a pixel is either selected or it is not; and (2) the fraction by which it is selected can vary – not the fraction of the physical size of the pixel, but rather the fraction of the strength of the selection. Since I think it is clear that a selection constitutes a channel, let's look at Masks instead, since these are more understandable for most of us. In the graphic below, I started with a photo, added a mask to it and drew a grey line on the mask. I've shown the result on the right side. Look at those pixels in the middle: are they masked or not? Of course they are. Are they fully masked? No, they are partially masked. And the fraction by which they are masked is exactly the fractional amount of greyness that exists in the Mask channel. Why can we not agree to apply the same logic to Selections, since Affinity Photo clearly sees the selection as a channel?

To understand selections, one must understand channels. Because a selection is a channel. Look at the Channels panel. Each and every layer is composed of a number of channels. When we look specifically at pixel layers in an RGBA document, each layer has red, green, and blue channels which denote color; there is also an alpha channel which is used for transparency. Look toward the bottom of the Channels panel. There is a separate channel called Pixel Selection. This channel contains the active selection. (1) It is fluid, in the sense that its contents will change depending on what, if anything, is selected. (2) It does not belong to a layer, but exists on its own. (3) Most importantly, like all channels, it has a single entry for each individual pixel. That last notion is important. A pixel is the most elementary unit of an image. Each pixel can contain one, and only one, color. Each pixel can contain only one level of transparency. And each pixel in the Pixel Selection channel can also include only a single value. This is why a single pixel cannot be two different colors. This is why a single pixel cannot be half opaque and half transparent. And it is why a single pixel is either selected or not, but also why a selected pixel can be partially selected. Let’s first clear up the “where is the 50% line” question. In the image below, I’ve created an elliptical selection and applied a 100 pixel feather to it. On the right, I’ve zoomed into the marching ants at 1400%. The marching ants line indicates the border at which pixels are 50% selected. PLEASE note that the line does not go through individual pixels. It denotes entire pixels, because each pixel can only be selected by a specific fraction (0% to 100%, or any value in-between) The answer to questions by @R C-R and @walt.farrell about how partial selection affects subsequent operations is really a fairly straightforward one. (1) Once a selection is made, that selection is stored inside the Pixel Selection channel. (2) In many cases, for instance in straightforward use of the marquee tools, the Pixel Selection channel is white where the selection is active, and black where the selection is not active. (3) In some other cases, such as Selection From Layer, Luminosity based selection, and feathered selections, the Pixel Selection channel contains pixels that are all shades of grey. These grey pixels within the Pixel Selection channel indicate document pixels which are partially selected. (4) Subsequent use of the selection acts on whatever layer is activated in the Layers panel. The specific action that is undertaken (whether that is a Copy command, the creation of a Mask or and Adjustment or Filter, or anything else) is modified by the values in the Pixel Selection channel. What that last clause means is that my actions are multiplied by the value of the Pixel Selection channel for each and every pixel. In other words, if the Pixel Selection channel is black for a particular pixel, then my action is multiplied by 0. If the Pixel Selection channel is white for a particular pixel, then my action is multiplied by 1. And, if the Pixel Selection channel is, for instance, 45% grey then my action is multiplied by 0.45. Once you start thinking of selections as a separate channel, not attached to any particular layer, they become easier to understand. Also, it becomes a lot easier to understand how a pixel can be partially selected, and how a mask or adjustment layer created based on such a selection may contain areas which are grey.

1) “Areas of a layer” seems to be a clear reference to pixels on that layer. 2) While selections exist independently of any particular layer, those selections will act on whatever layer is active.

The Help topic discusses “areas” of layers. If that’s not a clear reference to pixels, I’m not sure how else to convince you. As is sometimes said about other, unrelated questions: “Some things are true, whether you believe in them or or not.”

From the Affinity Photo Help (online), in the section regarding "Pixel Selections from Layers": "You can create pixel selections based on layers (or layer groups) or layer luminance. "If the layer or layer group contains areas which have an opacity lower than 100%, these are partially selected. This partial selection is based on the percentage of their opacity (i.e. areas of 20% opacity will be selected by 20%). Transparent areas will not be included in the selection. "A selection marquee only appears around areas which are selected by more than 50%. Areas selected by 50% or less will not display a marquee at their edges."

So, here's another video. I've tried to demonstrate a couple of things. (1) Select All and Selection from Layer work differently, in that only Selection from Layer takes the layer's alpha channel into account. (2) The selection is independent of any particular layer. Even when layers are hidden (or when none are active) the selection still exists. (3) A selection which has been created, and which remains active, can act on a different layer. (4) The "marching ants" exist at the point where pixels are selected 50% or more. In the video, note that the marching ants are present right down the middle of the canvas (since they were based on a linear gradient). (5) When an adjustment layer is created with an active selection that contains "partially selected" pixels, the adjustment layer's mask can be anything from white to black, and this is dependent on the degree of selection of the pixels when the adjustment was first created. I know that was quite a mouthful. So, here's a video... Partial Selection Visualized.mp4

You say tomato, I say tomato. (That sounds better out loud, though, doesn’t it?) I think we’re saying effectively the same thing here. I think what this thread has shown me is that I need to do some more reading on alpha channels, since I’m pretty sure that’s where the salient information is.

To say that the pixel is "partially" selected does not (I don't think) mean to imply that a percentage of that pixel's size is selected. It means, in some sense, that the selection is only fractionally active. I have always thought of "selections" as if they were temporary Spare Channels, in the sense that some pixels are "on" and some are "off". The "on" pixels are the ones on which a subsequent action would be undertaken. For instance, if I use the Marquee tool to select some of my pixels and then Copy them, it is only the selected pixels (the "on" pixels) that are copied. I understand the opacity of a layer to be the degree to which it occludes the layer beneath it. So, a layer that is set to 50% opacity will only partially occlude the layer underneath it. Partial selection of pixels is some hybrid of segregating pixels into "on" and "off" pixels, and combining that with a concept similar to opacity in the sense that an "on" pixel might only be "partially on." It is like having a dimmer switch for individual parts of the selection. A perfect example of this is a Luminosity Mask. In Affinity Photo, the simplest way to make a luminosity mask is to Command-Option-Click on a layer icon. This results in a selection, but a subsequent mask is not all white or all black, nor is it white in selected areas and black in unselected areas; it is shades of grey. This is because the Command-Option-Click thing caused a "partial selection" of all pixels based on their luminosity.

Here's the simplest way I can think of to understand the difference between Select All and Selection from Layer. (1) Create a new document and add a single, blank pixel layer. (2) Fill that layer with any color you want. (3) Now, use the Eraser tool to erase some of the pixels. If you look at the Channels panel, you should see that the Alpha channel for that layer is white in all areas that contain color, but is black where you erased. Now, choose Select All. You should see that the entire layer has been selected. Deselect and instead choose Selection From Layer. Now, you should see that your selection includes ONLY the pixels that remain colored, but the areas where you erased are not selected. My interpretation is simply this: Select All will select all the pixels, without regard to the Alpha Channel for that layer. Selection From Layer, on the other hand, takes the layer's Alpha channel into account, and will not select transparent pixels.

@R C-R – I'm guessing here. If you don't bother changing anything in Blend Options and do a Select All, then all of the pixels are selected. Furthermore, the Alpha Channel for the layer is presumably all white (meaning that the Alpha Channel is set to 100% for all pixels). Choosing a Select All (or, choosing Selection From Layer) will (i) select all the pixels; and (ii) use the Alpha Channel for an indication of "how much" they are selected. Since the entire Alpha Channel is 100%, then all of the pixels are completely selected and the mask in a subsequent Adjustment layer is white. If you set the Blend Options to 50%, as I did previously, this does NOT change the layer opacity setting, but it DOES change the layer's Alpha Channel. When you do a Selection From Layer (although not when you do a Select All) you select all the pixels, but then use the Alpha Channel to determine how much they are selected. In this case, since the Alpha Channel is set to 50% throughout, then all of the selected pixels are 50% selected. In this case, when you create an Adjustment layer, its mask is set to 50% grey since this reflects the 50% selection of all of the layer's pixels. If you set the Blend Options to 50% then you have changed the Alpha Channel to 50% grey. If you do a Selection From Layer, then you have selected all of the pixels at 50%. This 50% selection survives resetting the Blend Options to 100%. Creating an Adjustment layer with that active selection (a 50% selection of all the pixels) will create a mask that is 50% grey in the Adjustment.

Try this, @R C-R. I was making this video while @Ron P. was posting his. Partial Selection.mp4

If one uses Blend Options as shown previously (a horizontal line at 50%) and simply closes the Blend Options dialog, 2 things change – first, the Layer Opacity remains at 100%; and second, the icon shown in the Composite Alpha line in the Channels panel is now 50% grey. I think this bears on the difference between alpha channels that are pre-multiplied and those that are computed (my terminology is undoubtedly wrong here). The blend options change the alpha channel and not the layer opacity setting. If you use the Blend Options to get the 50% grey alpha channel, then using Selection From Layer gives you a 50% selection of all the pixels. If you simply lower the opacity of the layer to 50%, then Select All or Selection From Layer will select all of the pixels at 100%. If you (a) use the Blend Options to set everything to 50%; (b) choose Selection From Layer; then (c) reset the Blend Options, you will not have changed the selection itself. As I said earlier, the selection is not intrinsically linked to any particular layer. Therefore, the 50% selection survives (as long as you don't DE-select) even if you change the Blend Options for the layer.

Hello, @R C-R. If, for instance, the entire document was 49% selected, (i) there would be no visible marching ants; (ii) any adjustment layer or live filter layer would automatically have its mask made grey with 49% luminosity; and (iii) inverting the pixel selection (not the document – my bad) would result in the entire document being 51% selected, in which case the marching ants would be visible. Also, as I said, I have no idea just how the OP managed to get a partial selection on his entire document. My example was only to point out that it is very possible. Also, for completeness sake, one can use Blend Options as indicated in my graphic, then use Selection From Layer, then (without deselecting) click the Revert button in the Blend Options dialog. This will keep the partial selection but re-establishes the 100% opacity of the multi-colored layer. I doubt that's what happened, since that sort of series of steps would be memorable(!), but it is one of (probably) several possibilities.

I don't know how the OP made the 50% selection, but it is indeed possible. Also, the marching ants will only be visible when the selection is 50% or greater (so perhaps this selection is just a fraction under 50%). Inverting the document will invert the selection as well, and when it becomes a fraction OVER 50%, the marching ants are now visible. Also, selections never belong to a layer. They are independent of layers, but will act on the selected layer when called upon to do so. One way to create a 50% selection would be to use the "Selection from Layer" command after using the Blend Options dialog on the multi-colored pixel layer, as shown here:

Although it would be nicer for Serif to implement something official, this solution has been available for the past 2 years. It is a free download, and I encourage everyone to see if it will work for them.

Good morning, @John Rostron. I was intrigued by your method, and tried it. I found that it produced a nice, sharp image in a different way. I thought there had to be a way to do all of this inside of a single file (and, therefore, make it amenable to an inclusive macro). I found that I could create the Light Edges and the Dark Edges inside of Groups, which were then rasterized. I then went about incorporating your instructions to a single macro. This brings together all of the steps you outlined above (except the creation of separate documents, of course) and then combines the Light and Dark Edges layers into a Group. In that way, the whole effect can be turned on/off with a single click. It can also be made less conspicuous by tweaking the Opacity of the group. I have attached the macro I created to this post. It is an .afmacros file, meaning it will import into the Library as a Macro Category. Users can drag the macro into one of their existing categories, if they like, and then discard the empty category they imported. I posted this as a category instead of as a single macro so that it could also be imported into the iPad version (although I confess I have not yet tested it out on my iPad – I am assuming it will work, and I hope I am correct). Sharpening by Blurring.afmacros.zip

If you're on a Mac and you want access to the .icns file, then (1) right-click on the Application itself, in the Applications folder; (2) choose "Show Package Contents"; (3) open the Contents folder, then open the Resources folder; (4) you'll find the .icns file inside that folder – it's named AppIcon.icns. Copy it and paste it onto the Desktop (or anywhere else, obviously); don't remove it from the Resources folder. The application icons, of various sizes, are all there.

Glad you liked this @Burch Russell.

oops…

The Pantone website also lists their Colors of the Year dating back to 2000. Obviously, this seemed like an .afpalette document waiting to happen. I have created such a palette, and it is available in a separate thread:

Earlier this morning, @William Overington posted a link to a collection of Pantone Electric Pastels. I created an .afpalette document for these colors, based on the RGB values given on the Pantone web site. You can find that thread at: https://forum.affinity.serif.com/index.php?/topic/146854-pantone-electric-pastels-article-and-palette/ Looking at the Pantone web site a little bit more, I came across a collection of their "Colors of the Year" dating from 2021 back to 2000. A list like that kind of begged for me to create another .afpalette file containing those colors. I have attached that file below. It can be loaded into Affinity Photo through the Swatches panel, using "Import Palette" at the bottom of the hamburger menu. I have imported these as an Application palette, so that they are available throughout Affinity Photo. Pantone Colors of the Year.afpalette