General Comments About Some Toolbox Widgets - Revision history

DrSlony at 21:39, 9 December 2019

2019-12-09T21:39:11Z

← Older revision		Revision as of 21:39, 9 December 2019
Line 1:		Line 1:
	<div class="pagetitle">General Comments About Some ~~Tool~~ Widgets</div>		<div class="pagetitle">General Comments About Some Toolbox Widgets</div>

	This article will enable you to use RawTherapee more efficiently and to take full advantage of features which even an experienced user may not know about. Take a few minutes to read it.		This article will enable you to use RawTherapee more efficiently and to take full advantage of features which even an experienced user may not know about. Take a few minutes to read it.

DrSlony at 21:38, 9 December 2019

2019-12-09T21:38:50Z

← Older revision		Revision as of 21:38, 9 December 2019
Line 1:		Line 1:
			<div class="pagetitle">General Comments About Some Tool Widgets</div>

	This article will enable you to use RawTherapee more efficiently and to take full advantage of features which even an experienced user may not know about. Take a few minutes to read it.		This article will enable you to use RawTherapee more efficiently and to take full advantage of features which even an experienced user may not know about. Take a few minutes to read it.

DrSlony: More updates, still not done

2018-12-30T23:06:19Z

More updates, still not done

← Older revision		Revision as of 23:06, 30 December 2018
Line 76:		Line 76:
	Most curves in RawTherapee have a color picker button [[File:Crosshair-node-curve.png]]. The color picker enables you to place a control point in a curve at the exact spot which corresponds to the area you're hovering over on the preview.		Most curves in RawTherapee have a color picker button [[File:Crosshair-node-curve.png]]. The color picker enables you to place a control point in a curve at the exact spot which corresponds to the area you're hovering over on the preview.

	Let's say you want to change the hue of a purple flower, to make it more blue. Without the color picker, you would have to guess the exact spot on the curve which corresponds hue of the flower, else the affected range of hues would be too wide and you might end up changing ~~something~~ you did not want to change. Using the color picker you simply click on the flower, and a control point appears on the curve which corresponds to that exact hue. You can adjust that control point as needed.		Let's say you want to change the hue of a purple flower, to make it more blue. Without the color picker, you would have to guess the exact spot on the curve which corresponds hue of the flower, else the affected range of hues would be too wide and you might end up changing hues you did not want to change. Using the color picker you simply click on the flower and a control point appears on the curve which corresponds to that exact hue. You can adjust that control point as needed.

	When the color picker button is clicked, the color picker is activated for the currently selected curve. Now when you hover the cursor over the preview you will notice that a vertical or horizontal line appears in the selected curve. This line represents the value of the ~~pixels~~ you're hovering over. To place a control point in the curve for the value you're hovering over, {{k\|Ctrl}}+{{k\|click}} the preview - a ~~node~~ will appear in the curve. You can adjust that ~~node~~ without leaving the preview area, just keep holding the left mouse button after you place the control point, and moving the mouse up and down moves the point up and down in the curve. Holding {{k\|Ctrl}} while editing a control point decreases your mouse speed so that you can very finely adjust that point. You will usually not require this precision, so after adding a new control point via {{k\|Ctrl}}+{{k\|click}}, let go of {{k\|Ctrl}} but keep holding the left mouse button.		When the color picker button is clicked, the color picker is activated for the currently selected curve. Now when you hover the cursor over the preview you will notice that a vertical or horizontal line appears in the selected curve. This line represents the value of the pixel you're hovering over. To place a control point in the curve for the value you're hovering over, {{k\|Ctrl}}+{{k\|click}} the preview - a control point will appear in the curve. You can adjust that control point without leaving the preview area, just keep holding the left mouse button after you place the control point, and moving the mouse up and down moves the control point up and down in the curve. Holding {{k\|Ctrl}} while editing a control point decreases your mouse speed so that you can very finely adjust that point. You will usually not require this precision, so after adding a new control point via {{k\|Ctrl}}+{{k\|click}}, let go of {{k\|Ctrl}} but keep holding the left mouse button.

	To deactivate the color picker, either {{k\|right-click}} anywhere in the preview area or {{k\|click}} on the same color picker button again.		To deactivate the color picker, either {{k\|right-click}} anywhere in the preview area or {{k\|click}} on the same color picker button again.
Line 84:		Line 84:
	You do not need to deactivate the previous curve's color picker to use it on a new curve, just activate it as usual, and the old one automatically deactivates.		You do not need to deactivate the previous curve's color picker to use it on a new curve, just activate it as usual, and the old one automatically deactivates.

	==== ~~Curve Node~~ In/Out ~~Value~~ ====		==== Control Point In/Out Values ====

	~~Introduced in version 4.2.192, each~~ curve has a ~~node~~ in/out ~~value input tool~~. You can use this tool for example to match ~~node values~~ on a photo of a color target ~~with known patch values~~.		Each curve has a button which lets you edit the selected control point's in/out values. You can use this tool, for example, to match a control point's "out" value on a photo of a color target to a reference value.

	The tool works with ~~nodes~~, and the most likely way you will create these ~~nodes~~ is by using the color picker. For this example, we will start with a curve without any ~~nodes~~ and create some using the color picker. Click the ~~node~~ value editor button [[File:Edit-point.png]] next to the curve, and also click the color picker button [[File:Crosshair-node-curve.png]]. You will now see "I" (in) and "O" (out) values displayed under the curve. They correspond to the point under the mouse cursor if you hover it over the curve. Hover the cursor over the ~~image~~ preview. Since you activated the color picker, you can Ctrl+click on a spot in the preview ~~area~~ to place a ~~node~~ which corresponds to that spot's value ~~in the curve~~ (whatever that value may be - for example for the L* curve, the value is the ~~internal value~~ of the pixel ~~you've placed~~ the ~~spot over at that point in RawTherapee~~'s ~~internal pipeline, and~~ the ~~output~~ value ~~is that value affected by your curve~~). Do that, Ctrl+click on a spot in the preview. A ~~node~~ appears in the curve. To edit the ~~node~~'s in/out values, right-click on the ~~node~~. It turns red with a red ring around it. Now you can edit the in/out values and see the ~~node~~ move in real-time. ~~Once~~ you are done editing, either right-click anywhere inside the curve area other than on ~~the node to go out of node editing mode~~, or just click the ~~node~~ value editor button again to deactivate it.		The tool works with control points, and the most likely way you will create these control points is by using the color picker. For this example, we will start with a curve without any control points and create some using the color picker. Click the control point in/out value editor button [[File:Edit-point.png]] next to the curve, and also click the color picker button [[File:Crosshair-node-curve.png]]. You will now see "I" (in) and "O" (out) values displayed under the curve. They correspond to the point under the mouse cursor if you hover it over the curve or over the preview. Hover the cursor over the preview. Since you activated the color picker, you can {{k\|Ctrl}}+{{k\|click}} a spot in the preview to place a control point in the curve which corresponds to that spot's value (whatever that value may be - for example for the L* curve the value is the lightness of the pixel under the cursor, for the RGB red curve it's the red value in the RGB space in the working profile). Do that, {{k\|Ctrl}}+{{k\|click}} on a spot in the preview. A control point appears in the curve. To edit the control point's in/out values, right-click on the control point. It turns red with a red ring around it. Now you can edit the in/out values and see the control point move in real-time. To go out of control point editing mode once you are done editing, either right-click anywhere inside the curve area other than on that control point, or just click the control point value editor button again to deactivate it.

	=== Tone Curves ===		=== Tone Curves ===
Line 98:		Line 98:
	[[File:Rt55 curve control cage.png\|frame\|right\|Control cage curve.]]		[[File:Rt55 curve control cage.png\|frame\|right\|Control cage curve.]]

	Tone curves serve to map an input value (on the horizontal or X axis) to an output value (on the vertical or Y axis). Though they may seem intimidating at first, after a little playing ~~everyone seems to~~ quickly develop an intuitive understanding. Curves can do everything "~~Levels~~" can do and much more, so the sooner you grasp how they work the better.		Tone curves serve to map an input value (on the horizontal or X axis) to an output value (on the vertical or Y axis). Though they may seem intimidating at first, after a little playing you will quickly develop an intuitive understanding. Curves can do everything "levels" can do and much more, so the sooner you grasp how they work the better.

	As an example, ~~consider~~ the "Standard curve" screenshot to the right ~~– part of~~ the [[Exposure]] tool. There are grid lines in the background at every 10% interval. The left end of the horizontal (input) axis represents pure black, then the shadows, then the mid-tones, then the highlights, and finally the right end represents pure white. Likewise, the vertical (output) axis represents pure black at the bottom, pure white at the top, and the same graduation between the two. If the curve is linear, i.e. a diagonal straight line from bottom-left to top-right, then the curve has no effect – every point on the curve has an output value identical to its input value. For the curve to have an effect, the line must be ~~bent~~ so ~~that any given~~ point's output value does not match its input value. The ~~nodes~~ you place on the curve are there just to help you control the curve, they do not matter in the calculations – what matters is the curve's shape. ~~A node~~ in the bottom-left part ~~of this example~~ pushes the curve down: the ~~node~~ lies at 10% on the "input" axis, but at only 5% of the output axis – this causes dark tones to be made even darker. The next ~~node~~ lies at 40% on the input axis and 60% on the output axis - those mid-tones will be made brighter. Since only the curve's shape matters, even though there are no more ~~nodes~~ in this example, the curve at input=60% has output=95%, which means that the bright areas will be made very bright, almost white. The curve at input=20% also has output=20%, so those dark tones won't change between the input and output.		As an example, look at the "Standard curve" (screenshot to the right) in the [[Exposure]] tool. There are grid lines in the background at every 10% interval. The left end of the horizontal (input) axis represents pure black, then the shadows, then the mid-tones, then the highlights, and finally the right end represents pure white. Likewise, the vertical (output) axis represents pure black at the bottom, pure white at the top, and the same graduation between the two. If the curve is linear, i.e. a diagonal straight line from bottom-left to top-right, then the curve has no effect – every point on the curve has an output value identical to its input value. For the curve to have an effect, the line must be non-linear so some point's output value does not match its input value. The ''control points'' you place on the curve are there just to help you control the curve, they do not matter in the calculations – what matters is the ''curve's'' shape. In the example screenshot, a control point in the bottom-left part pushes the curve down: the control point lies at 10% on the "input" axis, but at only 5% of the output axis – this causes dark tones to be made even darker. The next control point lies at 40% on the input axis and 60% on the output axis - those mid-tones will be made brighter. Since only the curve's shape matters, even though there are no more control points in this example, the curve at input=60% has output=95%, which means that the bright areas will be made very bright, almost white. The curve at input=20% also has output=20%, so those dark tones won't change between the input and output.

	There are multiple types of curves at your disposal:		There are multiple types of curves at your disposal:

DrSlony: updating text

2018-12-25T23:52:52Z

updating text

← Older revision		Revision as of 23:52, 25 December 2018
Line 40:		Line 40:
	== Curves ==		== Curves ==

	RawTherapee has three ~~categories~~ of curve widgets:		RawTherapee has three kinds of curve widgets:
	* Tone curves		* Tone curves
	* Equalizer curves		* Equalizer curves
	* Threshold curves		* Threshold curves

	~~Tone~~ and equalizer ~~curves come in several types~~, ~~where each type plots~~ the curve ~~differently~~ based on ~~the position of~~ the control points you ~~placed~~. The type ~~can be selected using~~ the drop-down, ~~where "linear" means that the~~ curve ~~has no effect~~, ~~effectively turned off~~. You can also click the type ~~drop-down~~ to toggle the visibility of the curve, to make the most of limited screen space. If a curve is not linear and the tool within which it lies is enabled, then that curve has an effect on the image regardless whether it's visible or not.		<div align="center">
			<gallery caption="Three general kinds of curves" perrow="3">
			File:Rt55 curve type tone.png\|The tone curve.
			File:Rt55 curve type equalizer.png\|The equalizer curve
			File:Rt55 curve type threshold.png\|The threshold curve.
			</gallery>
			</div>

			[[File:Rt55 curves.png\|frame\|1- Curve type.<br>2- Curve mode.]]

			The shape of a tone curve and of an equalizer curve is defined based on control points which you create and position with the mouse. When a curve is linear, that means that the input matches the output, and so the curve has no effect. When a curve is not linear, it has an effect on the image.

			A curve is plotted based on the control points which you create and position. The same control points can lead to different curve shapes by changing the underlying math, and you can control this math by choosing a tone curve type in the drop-down list:
			* [[File:curve-linear-small.png]] Linear,
			* [[File:curve-spline-small.png]] Standard,
			* [[File:curve-catmullrom-small.png]] Flexible,
			* [[File:curve-parametric-small.png]] Parametric,
			* [[File:curve-nurbs-small.png]] Control cage.

			You can also click the curve type button to toggle the visibility of the curve. This allows you to make the most of the limited vertical screen space. If a curve is not linear and the tool within which it lies is enabled, then that curve has an effect on the image regardless whether it is visible or not.

	Each curve can be reset [[File:Undo-small.png]] to the default value. Some curves come in groups, such as the [[Lab Adjustments]] curves. There is one reset button for the whole group, and it applies to the currently selected curve. Click on the curve type drop-down button to select that curve.		Each curve can be reset [[File:Undo-small.png]] to the default value. Some curves come in groups, such as the [[Lab Adjustments]] curves. There is one reset button for the whole group, and it applies to the currently selected curve. Click on the curve type drop-down button to select that curve.
Line 53:		Line 72:
	=== Color Picker ===		=== Color Picker ===

	[[~~image~~:~~rt pipette 2~~ lab ba.~~jpg~~\|thumb~~\|900px~~\|The color picker pinpointed the exact hue of the purple flower to easily ~~make~~ it ~~more red using the HH curve~~.]]		[[File:Rt55 lab hh color picker.png\|thumb\|The color picker pinpointed the exact spot which corresponds to the hue of the purple flower, allowing you to easily manipulate it.]]

	Most curves in RawTherapee have a color picker button [[File:Crosshair-node-curve.png]]. This feature is a great way to target specific hues, tones and areas of a particular saturation, and using it will make tweaking your images easier and faster. Let's say you want to change the purple hue of a flower, to make it more red. Without the color picker, you ~~would have~~ to ~~guess~~ the exact ~~shade of the hue, else the affected range of hues would be too wide and you might end up changing something you did not want~~ to ~~change. With~~ the ~~color picker,~~ you ~~simply click~~ on the ~~flower, and a point appears in the relevant curve. You can adjust this point to your liking, knowing it represents the exact hue you want affected~~.		Most curves in RawTherapee have a color picker button [[File:Crosshair-node-curve.png]]. The color picker enables you to place a control point in a curve at the exact spot which corresponds to the area you're hovering over on the preview.

	~~The~~ color picker ~~must be activated for each curve~~, ~~simply by clicking on it. Now when~~ you ~~hover~~ the ~~cursor over~~ the ~~main preview you will notice that a vertical line (or even four~~ of ~~them) appears in~~ the ~~curve panel. This line represents~~ the ~~value~~ of ~~interest of the pixels~~ you~~'re hovering over~~. ~~To place an adjustment point in~~ the ~~curve for the value~~ you~~'re hovering over, Ctrl+leftclick in~~ the ~~preview~~, and a ~~dot~~ appears in the curve. You can adjust that point without leaving the preview area, just keep holding the left mouse button after you placed the curve point, and moving the mouse up and down moves the point up and down. Remember that holding Ctrl while editing a curve point decreases your mouse speed so that you can very finely adjust points, but usually you will not need this, so after Ctrl+leftclicking to place the point, let go of Ctrl, but keep holding the left mouse button.		Let's say you want to change the hue of a purple flower, to make it more blue. Without the color picker, you would have to guess the exact spot on the curve which corresponds hue of the flower, else the affected range of hues would be too wide and you might end up changing something you did not want to change. Using the color picker you simply click on the flower, and a control point appears on the curve which corresponds to that exact hue. You can adjust that control point as needed.

	To deactivate the color picker, either right-click anywhere in the preview area or ~~left-~~click on the same color picker button again.		When the color picker button is clicked, the color picker is activated for the currently selected curve. Now when you hover the cursor over the preview you will notice that a vertical or horizontal line appears in the selected curve. This line represents the value of the pixels you're hovering over. To place a control point in the curve for the value you're hovering over, {{k\|Ctrl}}+{{k\|click}} the preview - a node will appear in the curve. You can adjust that node without leaving the preview area, just keep holding the left mouse button after you place the control point, and moving the mouse up and down moves the point up and down in the curve. Holding {{k\|Ctrl}} while editing a control point decreases your mouse speed so that you can very finely adjust that point. You will usually not require this precision, so after adding a new control point via {{k\|Ctrl}}+{{k\|click}}, let go of {{k\|Ctrl}} but keep holding the left mouse button.

			To deactivate the color picker, either {{k\|right-click}} anywhere in the preview area or {{k\|click}} on the same color picker button again.

	You do not need to deactivate the previous curve's color picker to use it on a new curve, just activate it as usual, and the old one automatically deactivates.		You do not need to deactivate the previous curve's color picker to use it on a new curve, just activate it as usual, and the old one automatically deactivates.

	~~<br style="clear: both">~~

	==== Curve Node In/Out Value ====		==== Curve Node In/Out Value ====

DrSlony: Updating, WIP

2018-12-25T16:02:29Z

Updating, WIP

Show changes

DrSlony: updated icon

2018-12-25T14:19:40Z

updated icon

← Older revision		Revision as of 14:19, 25 December 2018
Line 88:		Line 88:
	Introduced in version 4.2.192, each curve has a node in/out value input tool. You can use this tool for example to match node values on a photo of a color target with known patch values.		Introduced in version 4.2.192, each curve has a node in/out value input tool. You can use this tool for example to match node values on a photo of a color target with known patch values.

	The tool works with nodes, and the most likely way you will create these nodes is by using the pipette. For this example, we will start with a curve without any nodes and create some using the pipette. Click the node value editor button [[~~image~~:~~Gtk~~-~~edit~~.png]] next to the curve, and also click the pipette's button [[File:Crosshair-node-curve.png]]. You will now see "I" (in) and "O" (out) values displayed under the curve. They correspond to the point under the mouse cursor if you hover it over the curve. Hover the cursor over the image preview. Since you activated the pipette, you can Ctrl+click on a spot in the preview area to place a node which corresponds to that spot's value in the curve (whatever that value may be - for example for the L* curve, the value is the internal value of the pixel you've placed the spot over at that point in RawTherapee's internal pipeline, and the output value is that value affected by your curve). Do that, Ctrl+click on a spot in the preview. A node appears in the curve. To edit the node's in/out values, right-click on the node. It turns red with a red ring around it. Now you can edit the in/out values and see the node move in real-time. Once you are done editing, either right-click anywhere inside the curve area other than on the node to go out of node editing mode, or just click the node value editor button again to deactivate it.		The tool works with nodes, and the most likely way you will create these nodes is by using the pipette. For this example, we will start with a curve without any nodes and create some using the pipette. Click the node value editor button [[File:Edit-point.png]] next to the curve, and also click the pipette's button [[File:Crosshair-node-curve.png]]. You will now see "I" (in) and "O" (out) values displayed under the curve. They correspond to the point under the mouse cursor if you hover it over the curve. Hover the cursor over the image preview. Since you activated the pipette, you can Ctrl+click on a spot in the preview area to place a node which corresponds to that spot's value in the curve (whatever that value may be - for example for the L* curve, the value is the internal value of the pixel you've placed the spot over at that point in RawTherapee's internal pipeline, and the output value is that value affected by your curve). Do that, Ctrl+click on a spot in the preview. A node appears in the curve. To edit the node's in/out values, right-click on the node. It turns red with a red ring around it. Now you can edit the in/out values and see the node move in real-time. Once you are done editing, either right-click anywhere inside the curve area other than on the node to go out of node editing mode, or just click the node value editor button again to deactivate it.

	=== Tone Curves ===		=== Tone Curves ===

DrSlony: updated icon

2018-12-25T14:17:53Z

updated icon

← Older revision		Revision as of 14:17, 25 December 2018
Line 129:		Line 129:
	** [[HSV Equalizer#V\|V]]		** [[HSV Equalizer#V\|V]]

	It's very simple to use once you understand it, so let's use the [[HSV Equalizer]] in the [[File:Color-circles.png]] Color tab as an example. Click on the drop-down icon [[image:Drop-down.png]] next to the H(ue) button and choose "''Minima/Maxima control points''" [[~~image~~:~~CurveType~~-~~controlPoints~~.png]]. You'll see six dots on the horizontal line in the middle and six vertical lines that cross these dots. Notice that those lines are colored; from left to right: red, yellow, green, aqua, blue and magenta. Now click on the very left dot (the cursor changes into a little hand) and move it slightly upward and downward. Result: red colors quickly change to green, blue and magenta as the cursor is moved up, and to pink, blue and green when moved down.		It's very simple to use once you understand it, so let's use the [[HSV Equalizer]] in the [[File:Color-circles.png]] Color tab as an example. Click on the drop-down icon [[image:Drop-down.png]] next to the H(ue) button and choose "''Minima/Maxima control points''" [[File:Curve-controlpoints-small.png]]. You'll see six dots on the horizontal line in the middle and six vertical lines that cross these dots. Notice that those lines are colored; from left to right: red, yellow, green, aqua, blue and magenta. Now click on the very left dot (the cursor changes into a little hand) and move it slightly upward and downward. Result: red colors quickly change to green, blue and magenta as the cursor is moved up, and to pink, blue and green when moved down.

	Notice that a new horizontal line appears when you start dragging a color point, and see how its color changes. The vertical axis represents input colors, and the horizontal axis output colors.		Notice that a new horizontal line appears when you start dragging a color point, and see how its color changes. The vertical axis represents input colors, and the horizontal axis output colors.

DrSlony: updated icon

2018-12-25T14:14:16Z

updated icon

← Older revision		Revision as of 14:14, 25 December 2018
Line 74:		Line 74:
	[[image:rt pipette 2 lab ba.jpg\|thumb\|900px\|The pipette tool pinpointed the exact hue of the purple flower to easily make it more red using the HH curve.]]		[[image:rt pipette 2 lab ba.jpg\|thumb\|900px\|The pipette tool pinpointed the exact hue of the purple flower to easily make it more red using the HH curve.]]

	Most curves in RawTherapee have a pipette button [[~~image~~:~~editmodehand~~.png]]. This feature is a great way to target specific hues, tones and areas of a particular saturation, and using it will make tweaking your images easier and faster. Let's say you want to change the purple hue of a flower, to make it more red. Without the pipette, you would have to guess the exact shade of the hue, else the affected range of hues would be too wide and you might end up changing something you did not want to change. With the pipette, you simply click on the flower, and a point appears in the relevant curve. You can adjust this point to your liking, knowing it represents the exact hue you want affected.		Most curves in RawTherapee have a pipette button [[File:Crosshair-node-curve.png]]. This feature is a great way to target specific hues, tones and areas of a particular saturation, and using it will make tweaking your images easier and faster. Let's say you want to change the purple hue of a flower, to make it more red. Without the pipette, you would have to guess the exact shade of the hue, else the affected range of hues would be too wide and you might end up changing something you did not want to change. With the pipette, you simply click on the flower, and a point appears in the relevant curve. You can adjust this point to your liking, knowing it represents the exact hue you want affected.

	The pipette tool must be activated for each curve, simply by clicking on it. Now when you hover the cursor over the main preview you will notice that a vertical line (or even four of them) appears in the curve panel. This line represents the value of interest of the pixels you're hovering over. To place an adjustment point in the curve for the value you're hovering over, Ctrl+leftclick in the preview, and a dot appears in the curve. You can adjust that point without leaving the preview area, just keep holding the left mouse button after you placed the curve point, and moving the mouse up and down moves the point up and down. Remember that holding Ctrl while editing a curve point decreases your mouse speed so that you can very finely adjust points, but usually you will not need this, so after Ctrl+leftclicking to place the point, let go of Ctrl, but keep holding the left mouse button.		The pipette tool must be activated for each curve, simply by clicking on it. Now when you hover the cursor over the main preview you will notice that a vertical line (or even four of them) appears in the curve panel. This line represents the value of interest of the pixels you're hovering over. To place an adjustment point in the curve for the value you're hovering over, Ctrl+leftclick in the preview, and a dot appears in the curve. You can adjust that point without leaving the preview area, just keep holding the left mouse button after you placed the curve point, and moving the mouse up and down moves the point up and down. Remember that holding Ctrl while editing a curve point decreases your mouse speed so that you can very finely adjust points, but usually you will not need this, so after Ctrl+leftclicking to place the point, let go of Ctrl, but keep holding the left mouse button.
Line 88:		Line 88:
	Introduced in version 4.2.192, each curve has a node in/out value input tool. You can use this tool for example to match node values on a photo of a color target with known patch values.		Introduced in version 4.2.192, each curve has a node in/out value input tool. You can use this tool for example to match node values on a photo of a color target with known patch values.

	The tool works with nodes, and the most likely way you will create these nodes is by using the pipette. For this example, we will start with a curve without any nodes and create some using the pipette. Click the node value editor button [[image:Gtk-edit.png]] next to the curve, and also click the pipette's button [[~~image~~:~~editmodehand~~.png]]. You will now see "I" (in) and "O" (out) values displayed under the curve. They correspond to the point under the mouse cursor if you hover it over the curve. Hover the cursor over the image preview. Since you activated the pipette, you can Ctrl+click on a spot in the preview area to place a node which corresponds to that spot's value in the curve (whatever that value may be - for example for the L* curve, the value is the internal value of the pixel you've placed the spot over at that point in RawTherapee's internal pipeline, and the output value is that value affected by your curve). Do that, Ctrl+click on a spot in the preview. A node appears in the curve. To edit the node's in/out values, right-click on the node. It turns red with a red ring around it. Now you can edit the in/out values and see the node move in real-time. Once you are done editing, either right-click anywhere inside the curve area other than on the node to go out of node editing mode, or just click the node value editor button again to deactivate it.		The tool works with nodes, and the most likely way you will create these nodes is by using the pipette. For this example, we will start with a curve without any nodes and create some using the pipette. Click the node value editor button [[image:Gtk-edit.png]] next to the curve, and also click the pipette's button [[File:Crosshair-node-curve.png]]. You will now see "I" (in) and "O" (out) values displayed under the curve. They correspond to the point under the mouse cursor if you hover it over the curve. Hover the cursor over the image preview. Since you activated the pipette, you can Ctrl+click on a spot in the preview area to place a node which corresponds to that spot's value in the curve (whatever that value may be - for example for the L* curve, the value is the internal value of the pixel you've placed the spot over at that point in RawTherapee's internal pipeline, and the output value is that value affected by your curve). Do that, Ctrl+click on a spot in the preview. A node appears in the curve. To edit the node's in/out values, right-click on the node. It turns red with a red ring around it. Now you can edit the in/out values and see the node move in real-time. Once you are done editing, either right-click anywhere inside the curve area other than on the node to go out of node editing mode, or just click the node value editor button again to deactivate it.

	=== Tone Curves ===		=== Tone Curves ===

DrSlony: updated icon

2018-12-19T13:16:59Z

updated icon

← Older revision		Revision as of 13:16, 19 December 2018
Line 129:		Line 129:
	** [[HSV Equalizer#V\|V]]		** [[HSV Equalizer#V\|V]]

	It's very simple to use once you understand it, so let's use the [[HSV Equalizer]] in the [[~~image~~:~~colour~~.png]] Color tab as an example. Click on the drop-down icon [[image:Drop-down.png]] next to the H(ue) button and choose "''Minima/Maxima control points''" [[image:CurveType-controlPoints.png]]. You'll see six dots on the horizontal line in the middle and six vertical lines that cross these dots. Notice that those lines are colored; from left to right: red, yellow, green, aqua, blue and magenta. Now click on the very left dot (the cursor changes into a little hand) and move it slightly upward and downward. Result: red colors quickly change to green, blue and magenta as the cursor is moved up, and to pink, blue and green when moved down.		It's very simple to use once you understand it, so let's use the [[HSV Equalizer]] in the [[File:Color-circles.png]] Color tab as an example. Click on the drop-down icon [[image:Drop-down.png]] next to the H(ue) button and choose "''Minima/Maxima control points''" [[image:CurveType-controlPoints.png]]. You'll see six dots on the horizontal line in the middle and six vertical lines that cross these dots. Notice that those lines are colored; from left to right: red, yellow, green, aqua, blue and magenta. Now click on the very left dot (the cursor changes into a little hand) and move it slightly upward and downward. Result: red colors quickly change to green, blue and magenta as the cursor is moved up, and to pink, blue and green when moved down.

	Notice that a new horizontal line appears when you start dragging a color point, and see how its color changes. The vertical axis represents input colors, and the horizontal axis output colors.		Notice that a new horizontal line appears when you start dragging a color point, and see how its color changes. The vertical axis represents input colors, and the horizontal axis output colors.

DrSlony: /* Curve Editors */

2018-12-17T15:54:09Z

Curve Editors

← Older revision		Revision as of 15:54, 17 December 2018
Line 44:		Line 44:
	RawTherapee has three types of curve editors – for Threshold Curves, Tone Curves and Flat Curves. They are discussed below along with some general pointers.		RawTherapee has three types of curve editors – for Threshold Curves, Tone Curves and Flat Curves. They are discussed below along with some general pointers.

	===Threshold Curves===		=== Threshold Curves ===

	Threshold Curves are the simplest. They are used to tell a RawTherapee tool the tones (or hues or saturations values) that you want processed (or processed differently).		Threshold Curves are the simplest. They are used to tell a RawTherapee tool the tones (or hues or saturations values) that you want processed (or processed differently).

Line 57:		Line 58:
	You may have noticed that Threshold Curves actually consist of a few straight lines rather than a curve. If this bothers you, you might want to take a break before moving on to Flat Curves.		You may have noticed that Threshold Curves actually consist of a few straight lines rather than a curve. If this bothers you, you might want to take a break before moving on to Flat Curves.

	===General Comments on Tone and Flat Curves===		=== General Comments on Tone and Flat Curves ===

	Tone and Flat Curves are more powerful than Threshold Curves and have some controls that aren’t needed on Threshold Curves.		Tone and Flat Curves are more powerful than Threshold Curves and have some controls that aren’t needed on Threshold Curves.

Line 69:		Line 71:

	==== Pipette ====		==== Pipette ====

	[[image:rt pipette 2 lab ba.jpg\|thumb\|900px\|The pipette tool pinpointed the exact hue of the purple flower to easily make it more red using the HH curve.]]		[[image:rt pipette 2 lab ba.jpg\|thumb\|900px\|The pipette tool pinpointed the exact hue of the purple flower to easily make it more red using the HH curve.]]

	Most curves in RawTherapee have a pipette button [[image:editmodehand.png]]. This feature is a great way to target specific hues, tones and areas of a particular saturation, and using it will make tweaking your images easier and faster. Let's say you want to change the purple hue of a flower, to make it more red. Without the pipette, you would have to guess the exact shade of the hue, else the affected range of hues would be too wide and you might end up changing something you did not want to change. With the pipette, you simply click on the flower, and a point appears in the relevant curve. You can adjust this point to your liking, knowing it represents the exact hue you want affected.		Most curves in RawTherapee have a pipette button [[image:editmodehand.png]]. This feature is a great way to target specific hues, tones and areas of a particular saturation, and using it will make tweaking your images easier and faster. Let's say you want to change the purple hue of a flower, to make it more red. Without the pipette, you would have to guess the exact shade of the hue, else the affected range of hues would be too wide and you might end up changing something you did not want to change. With the pipette, you simply click on the flower, and a point appears in the relevant curve. You can adjust this point to your liking, knowing it represents the exact hue you want affected.

Line 81:		Line 85:

	==== Curve Node In/Out Value ====		==== Curve Node In/Out Value ====

	Introduced in version 4.2.192, each curve has a node in/out value input tool. You can use this tool for example to match node values on a photo of a color target with known patch values.		Introduced in version 4.2.192, each curve has a node in/out value input tool. You can use this tool for example to match node values on a photo of a color target with known patch values.

	The tool works with nodes, and the most likely way you will create these nodes is by using the pipette. For this example, we will start with a curve without any nodes and create some using the pipette. Click the node value editor button [[image:Gtk-edit.png]] next to the curve, and also click the pipette's button [[image:editmodehand.png]]. You will now see "I" (in) and "O" (out) values displayed under the curve. They correspond to the point under the mouse cursor if you hover it over the curve. Hover the cursor over the image preview. Since you activated the pipette, you can Ctrl+click on a spot in the preview area to place a node which corresponds to that spot's value in the curve (whatever that value may be - for example for the L* curve, the value is the internal value of the pixel you've placed the spot over at that point in RawTherapee's internal pipeline, and the output value is that value affected by your curve). Do that, Ctrl+click on a spot in the preview. A node appears in the curve. To edit the node's in/out values, right-click on the node. It turns red with a red ring around it. Now you can edit the in/out values and see the node move in real-time. Once you are done editing, either right-click anywhere inside the curve area other than on the node to go out of node editing mode, or just click the node value editor button again to deactivate it.		The tool works with nodes, and the most likely way you will create these nodes is by using the pipette. For this example, we will start with a curve without any nodes and create some using the pipette. Click the node value editor button [[image:Gtk-edit.png]] next to the curve, and also click the pipette's button [[image:editmodehand.png]]. You will now see "I" (in) and "O" (out) values displayed under the curve. They correspond to the point under the mouse cursor if you hover it over the curve. Hover the cursor over the image preview. Since you activated the pipette, you can Ctrl+click on a spot in the preview area to place a node which corresponds to that spot's value in the curve (whatever that value may be - for example for the L* curve, the value is the internal value of the pixel you've placed the spot over at that point in RawTherapee's internal pipeline, and the output value is that value affected by your curve). Do that, Ctrl+click on a spot in the preview. A node appears in the curve. To edit the node's in/out values, right-click on the node. It turns red with a red ring around it. Now you can edit the in/out values and see the node move in real-time. Once you are done editing, either right-click anywhere inside the curve area other than on the node to go out of node editing mode, or just click the node value editor button again to deactivate it.

	===Tone Curves===		=== Tone Curves ===
	Tone Curves are somewhat misnamed since, while some are used to adjust tones, others are used to adjust saturation, chromaticity or other properties. Their purpose is to map an input value (on the horizontal or X axis) to an output value (measured on the vertical or Y axis). If Math isn’t your first language, don’t worry – after a little playing with them, everyone seems to quickly develop an intuitive understanding.

	[[~~Image~~:~~Tone_Curve~~.png\|right\|frame\|~~Tone Curve showing type drop down~~]]		[[File:Rt55 curve linear.png\|frame\|right\|Linear curve.]]
			[[File:Rt55 curve standard.png\|frame\|right\|Standard curve.]]
			[[File:Rt55 curve flexible.png\|frame\|right\|Flexible curve.]]
			[[File:Rt55 curve parametric.png\|frame\|right\|Parametric curve.]]
			[[File:Rt55 curve control cage.png\|frame\|right\|Control cage curve.]]

	As an ~~example, consider~~ the ~~figure~~ to the ~~right – part of the [[Exposure]] tool~~. ~~The left part of the graph represents the darker tones~~, ~~the right part represents the brighter tones of the photo~~. ~~You~~ can ~~see that the bottom left of the curve has been moved up. This will cause dark areas to be boosted. Similarly~~ the ~~top right of the curve has been pulled down, cutting back~~ the ~~bright areas~~.		Tone curves serve to map an input value (on the horizontal or X axis) to an output value (on the vertical or Y axis). Though they may seem intimidating at first, after a little playing everyone seems to quickly develop an intuitive understanding. Curves can do everything "Levels" can do and much more, so the sooner you grasp how they work the better.

	The ~~figure shows~~ the curve ~~type drop~~ down. ~~Tone curves allow four different ways of manipulating~~ the curve:		As an example, consider the "Standard curve" screenshot to the right – part of the [[Exposure]] tool. There are grid lines in the background at every 10% interval. The left end of the horizontal (input) axis represents pure black, then the shadows, then the mid-tones, then the highlights, and finally the right end represents pure white. Likewise, the vertical (output) axis represents pure black at the bottom, pure white at the top, and the same graduation between the two. If the curve is linear, i.e. a diagonal straight line from bottom-left to top-right, then the curve has no effect – every point on the curve has an output value identical to its input value. For the curve to have an effect, the line must be bent so that any given point's output value does not match its input value. The nodes you place on the curve are there just to help you control the curve, they do not matter in the calculations – what matters is the curve's shape. A node in the bottom-left part of this example pushes the curve down: the node lies at 10% on the "input" axis, but at only 5% of the output axis – this causes dark tones to be made even darker. The next node lies at 40% on the input axis and 60% on the output axis - those mid-tones will be made brighter. Since only the curve's shape matters, even though there are no more nodes in this example, the curve at input=60% has output=95%, which means that the bright areas will be made very bright, almost white. The curve at input=20% also has output=20%, so those dark tones won't change between the input and output.
	* '''Linear:''' The default type - a straight line that results in no change to input values. The mathematically inclined may observe that it is a graph of y=x. The rest of us just set the control to linear to “turn off” the curve.
	* '''~~Custom:~~''' The type most commonly seen in other software. Click to drop a control point anywhere on the curve and then drag the control point to change the ~~curve’s~~ shape. The top-right point represents the brightest areas in the photo. Drag that point vertically down to make the highlights less bright; move it horizontally to the left to make bright areas brighter, perhaps at the cost of some overexposure. The bottom-left point represents the darkest areas in the photo. Move that point horizontally to the right to make the photo darker, perhaps at the cost of some underexposure. Move it vertically up to make the darks lighter.		There are multiple types of curves at your disposal:
	* '''Parametric:''' Allows you to use sliders rather than dragging the curve directly. For the Parametric curve type, clicking the right mouse button over the zone selector ([[Image:Parametric_curve_bar.png]]) will reset the handles' position to their default values. (The global reset button will reset them too.)		* '''Linear'''
	* '''Control Cage:''' At first sight this curve type looks very much like the Custom curve, but there are some differences. With the Custom curve, the curve touches all the control points. This is not the case with the control cage curve – the control points attract the curve towards them but the curve doesn’t actually go through them. Another difference is that the control cage allows for a straight section of the curve, while you can't do this with the custom curve. The cage curve needs at least three points for that (so five in total). Holding down the Shift key while dragging a point will help you to easily create a straight line by snapping the point to the line made by the previous and next point (displayed in red by the 'snap to' tool). Many users prefer Control Cage type curves to the alternatives.		: The default type - a straight line that results in no change to input values. The mathematically inclined may observe that it is a graph of y=x. The rest of us just set the control to linear to “turn off” the curve.
			* '''Standard'''
			: The type most commonly seen in other software. Click to drop a control point anywhere on the curve and then drag the control point to change the curve's shape. The top-right point represents the brightest areas in the photo. Drag that point vertically down to make the highlights less bright; move it horizontally to the left to make bright areas brighter, perhaps at the cost of some overexposure. The bottom-left point represents the darkest areas in the photo. Move that point horizontally to the right to make the photo darker, perhaps at the cost of some underexposure. Move it vertically up to make the darks lighter.
			* '''Flexible'''
			: A characteristic of the "Standard" cubic spline curve is that editing one node could have a huge impact on what happens to the curve in relation to the other nodes. The "Flexible" centripetal Catmull–Rom spline curve allows you to make adjustments to any part of the curve with little impact on the other parts.
			* '''Parametric'''
			: Allows you to use sliders rather than dragging the curve directly. For the Parametric curve type, clicking the right mouse button over the zone selector ([[Image:Parametric_curve_bar.png]]) will reset the handles' position to their default values. (The global reset button will reset them too.)
			* '''Control Cage'''
			: At first sight this curve type looks very much like the Custom curve, but there are some differences. With the Custom curve, the curve touches all the control points. This is not the case with the control cage curve – the control points attract the curve towards them but the curve doesn’t actually go through them. Another difference is that the control cage allows for a straight section of the curve, while you can't do this with the custom curve. The cage curve needs at least three points for that (so five in total). Holding down the Shift key while dragging a point will help you to easily create a straight line by snapping the point to the line made by the previous and next point (displayed in red by the 'snap to' tool). Many users prefer Control Cage type curves to the alternatives.

	=== The Flat Curve ===		=== The Flat Curve ===

	[[image:Flat curve justcurve.png\|frame\|The input color green (vertical line) was changed to the output color blue (horizontal line).]]		[[image:Flat curve justcurve.png\|frame\|The input color green (vertical line) was changed to the output color blue (horizontal line).]]
	A number of tools in RawTherapee use the ''flat curve'':		A number of tools in RawTherapee use the ''flat curve'':