Photoshop Masking and Compositing Chapter 2 Selection Strategies and Essentials
pathfinder
Super Moderators Posts: 14,708 moderator
Chapter 2 - Selection Strategies and Essentials
The author begins by stating that there are usually three to five ways of accomplishing anything in Photoshop. The longer I work with and learn PS, the more verity I discover in her statement. In other words, we need to know more than one way to skin a cat, or make a selection in an image.
Chapter 2 will teach us how Photoshop creates selections from our inputs. We will learn how to analyze an image to create the easiest path to a selection. We will learn about the Marquee, Elliptical, Lasso tools, and the Magic Wand and the Quick Mask mode. And the value of combining more than one tool or technique to accomplish our selections.
What on Earth is a Selection, ANYWAY!!??
You can edit an image either one of two ways, Globally OR Locally. A Global edit is a change that is applied uniformly to the whole image - like a Photo Filter for example, found by typing Image>Adjustments>Photo Filter which then brings up this box
Here is an image of an egret of mine
Here is the image after a global filter with the Photo Filter command of the 85A warming filter at 75% to the whole image - notice the change in color of all of the bird and the sky
And here is the filter applied LOCALLY to the bird ONLY, that I selected by using the Color Select Command
Notice how the bird’s white feathers have been warmed, but the sky and the beak have not been changed because the effect was applied to ONLY the LOCAL selection. Here is the local selection complete with the marching ants displayed
So local selections can be useful things to know how to do. But what are they really, in Photoshop??
When you make a selection in PS using any of the typical selection tools, the selection is outlined by “Marching Ants” - a series of blinking dashes, but Photoshop does not see things that way.
Photoshop actually references parts of the image to an active or an inactive area in the grey scale layers of the image. Selected areas are WHITE, and Deselected areas are Black.
So the area inside the “Marching Ants” is White or active, and the area outside your selection is Black or inactive. The dividing line between selected and non-selected can be a sharp black line or a faded grey gradient depending on how you set up your selection tools with the Feather command.
A Feather of ‘0’ will give a very sharp border, but a feather of 10 may create a soft border on a small image with just a few pixels, or a sharper border on a larger image with lots of Megapixels. So try to think of your selections inside the marching ants as a white image on a black background, because that is how Photoshop will display it later when you get to Quick Masks.
The author then spends a little time discussing Shape and Form and how they can be used to decide which Selection tools to utilize. Shape selections are usually geometric - squares, circles, rectangle, polygons etc - and are usually manmade. Forms are more organic structures with smooth edges and flowing contours.
Tone and Color can also be used for selections, as I did with the egret images above. Some times it is easier to select what you do not want, and then Invert the selection with the Invert command in PS. That is how I selected the egret - I selected the blue sky and then Inverted the selection.
Edges and Fine Detail like wisps of hair give most Photoshop editors the willies. Soft edged images like moving automobiles or blurred out of focus images are other details that can challenge your selecting skills. As are Translucency and Light and wisps of smoke.
Geometric Shape Selections
The Marquee, Polygon Lasso and Pen tools are the tools for Geometric selecting. It would be tedious indeed to try outlining the feathers in the egret I posted with any of the geometric tools. The Pen tool deserves its own chapter, and will be covered in detail in Chapter 3.
The Marquee tool can be found in the Tools palette on the upper left side
Outlining the Prestolite sign in this image should be rather easy.
.
The Polygon selection tool will select it with 4 quick clicks. Or the Marquee tool can select it with a click and a drag of the mouse. The round wheel could be selected by the Marquee tool, by pressing the [Option and Shift] keys while dragging with the mouse from the center.
The author then goes on and spends four pages describing the various modalities and key strokes of the Marquee tool and the Polygon tool. For example, to select a perfect square, hold the SHIFT key while dragging the Rectangular or Elliptical marquee tool. Press the Option or Alt key to start from the center point.
I am not going to describe in detail each and every keystroke needed to use the Marquee and Polygon Lasso tools as they need to be practiced and used until they become second nature. I urge the reader to spend the time learning the keystrokes required to use the Rectangular and Elliptical selection tools.
I find I use the Polygonal Selection tool much more frequently as the selections from photographic images are usually not perfect squares or rectangle or circles, but more polygonal shapes that I can walk around clicking the Polygonal selection tool as I go to gather the form.
If you click outside of your selection, you are beginning a new selection, and have discarded the old selection. The key board manner of discarding your selection is [ctrl+D] or [command+d] on the Mac.
The author describes a neat way of selecting circles and ovals without guesswork. Select View>Show Rulers. Drag out four guides that just touch the edge of the needed selection. With the Elliptical Marquee tool, click the upper left corner of the intersection of the guides and drag to the lower-right intersection of the guides. If necessary, you may need to use the Select>Select Transform to scale and shape the selection outline.
Selection tool Options
When using a tool, it is a good idea to inspect the tool bar at the top of the screen to verify the setting of the tool utilized.
Feather
Feathering softens the edges of a selection to both the inside and the outside of the initial selection. Feathering creates a gradient in the grayscale image that represents the area of selection. The author goes on the say that she does not recommend using a Feather amount in the Options bar, because you cannot see the results of the feathering with the selection tool. She recommends using the Gaussian blur tool in the Quick Mask mode so that you can visually see the effect on the Mask, which she will discuss further in Chapter 3.
Anti-Aliasing
Its best to leave Anti-Aliasing on unless you know why you want to turn it off, for example, tiny icons for the WEB or graphical drawing created by an artist.
Style
When the Rectangular or Elliptical Marquee tool is active, you can choose three different styles of actions. Normal, or Constrained Aspect Ratio, and Fixed Size.
Normal style lets you make a rectangle of any size you wish. Constrain Aspect ratio lets you specify the ratio between the height and width of the rectangle, 1 to 1 would be a perfect square. A ratio of 2 height by 3 width will create a perfect 35mm aspect ratio of 24 by 36 mm. Fixed size is very useful as it allows you to specify a final image size such as 4 by 5 inches that will match standard 8x10 printing paper.
Selecting Non-Geometric Shape-Based Subjects
Not all shapes are perfect squares or rectangles as I mentioned earlier. The Polygon Lasso tool and the Pen Tool are very useful in these situations.
The Polygon tool makes perfectly straight lines between clicks of the mouse. When your selection is competed, double clicking the end where you began competes the selection and starts the marching ants, or you can hit the Return Key..
The author suggests using the Polygon Tool on the image at its full size by hitting [ctrl+0(zero key)+Alt] or Command+Option+0 on the Mac which brings up the image at 100% size. For more detail hit command and the plus key simultaneously, to step up the magnification. Hit command and the minus key simultaneously to reduce the image magnification.
If you run out of space on the screen, press and hold the space bar and the selection tool transforms to the Hand tool which lets you grab the image and move it around as needed. After an initial selection with the Polygon tool, you will need to inspect the edges of the selection at higher magnification and use the Lasso tool to free hand add or subtract from your selection. Holding down the shift key adds to your selection if you begin in the area already selected. Holding down the alt/option key subtracts the selection from your already selected area. Once the selection is complete it can be copied and pasted with ctrl-C and ctrl-V. It can be moved in the image by holding down the V key. And best of all, it can be saved as an Alpha channel if the file is saved as a PSD or a TiFF.
Form Based Selections
The Standard Lasso tool lets you select objects that are organically shaped without straight lines. Click and hold the mouse button down to let you draw like a pen around the object selected. You can turn the Lasso tool into the Polygon tool by Option-clicking (Alt-clicking) your way around an objects using straight lines and then back to curved lines again with the Lasso tool. Again the reader needs to spend some time practicing using the Lasso and the Polygon tool making selections until they are second nature. This is more like riding a bicycle than thinking in some ways.
Adding, Subtracting, and Intersecting Selections
Moving your selection tool inside your selection changes the appearance of the tool to a rectangle with an arrow pointing to it. If it is outside your selection, your selection tool remains unchanged.
If you want to add and area to your selection, hold down the Shift Key and draw from your selection to the area outside that needs to be included. If you want to exclude an area, hold down the option/alt key to remove part of your selection beginning from within the selection.
Intersecting with a Selection
You can begin a selection with the Magic Wand and then use the Marquee tool to choose a smaller rectangular area of the first selection. When using the Marquee or Lasso tools to add, subtract, or intersect a selection, be sure that the feather amount in the Options bar is the same, or the edges of your selections will vary, and look funky as a result.
Color and Tone Selections
There are three tools useful for selecting on the basis of color. The Magic Wand tool, the Magnetic Lasso Tool, and the Color Select Command.
The Magic Wand tool
The Magic Wand is a quick tool for selecting when the background is a uniform color that is not in the area of selection. Unfortunately, in real world photographs this rarely happens. The Magic wand tool can be used if the subject stands out clearly a different color than the background. There are four settings for the Magic Wand Tool, Tolerance, Contiguous, Use All Layers, and the Sample Size for the Eye Dropper Tool.
The Tolerance setting sets the range of brightness levels from 1 to 255 that it allows. Although it is called the Magic Wand, it really selects ranges of Brightness, instead of color, as the Magic Wand does not really look at Color, but only Brightness levels. (Maybe it would work better in the Lightness Channel of LAB ?? as there is little variation in the A and B channels there)
The Magic Wand selects based on an average reading of all three channels in RGB or four channels in CMYK, which makes the Wands performance difficult to predict sometimes. It works well sometimes, but awful at others. As a result, the author suggest inspecting each of the three RBG channels, and finding the channel with the greatest contrast in the area of the needed selection to make the selection with the Magic Wand in that channel. This is a really good tip!! After selecting in the Red channel for instance as in the book, she then types [Cmd+~] or [Ctrl+~} to review the composite three channel color image again.
Again she suggests leaving anti-aliasing on at all times, unless selecting flat graphic colors from a drawing rather than a photograph.
Contiguous is on by default, and means that the color/tonality must be in contact - contiguous - throughout the area of selection. Turning Contiguous OFF, means that the selected color will be picked through out the whole image - Globally.
Use ALL Layers determines whether the Magic Wand uses only the visible layer or the whole stack of layers of the document. This can be helpful in selecting a particular tone that exists on multiple layers.
The Sample Size of the EYE DROPPER Tool helps determine how large the area the Magic Wand uses for its calculations. The 3x3 eye dropper size seems to work better than a single pixel which can be unintended chosen poorly and not represent what you thought you were choosing.
The Magnetic Lasso Tool
The Magnetic Lasso is a tool that gets used a lot, sometimes for quick and dirty trial runs, and sometimes for detailed work. It is easier to use than the Lasso or Polygon Lasso tool also.
To use the Magnetic Lasso tool, start with an area of sharp contrast in your image and click the mouse button. The Magnetic Lasso will enter a point on the image and then lay down a line of marching ants that tend to follow the line of contrast established by your first click. Then keep the cursor where you want the selection to be and click as you gradually move along and the Magnetic Wand will lay down a series of dots and lines following your cursor path, even if you are a little off the actual track in the image. It tends to follow the area of contrast that you identify when you click each time on the selection.
The Feather and Anti-Aliasing works as with the other selection tools.
Width tells the Magnetic Lasso how far from its center point (from 1-40 pixels) to detect an image contrast line. Use lower settings to increase the precision, and prevent the tool from selecting areas nears your selection that might be similar in contrast.
Edge Contrast constrains the Magnetic Lasso to look for a minimum degree of contrast between the selection and the background. Use higher settings >30% for images that are quite different from the background, and lower settings for low contrast images.
Frequency determines the rate at which points are anchored by the Magnetic Lasso tool. The higher the frequency, the faster points are put down. For simple smooth lines lower frequency may be adequate, but for complex images, higher frequencies may be more useful.
Style Pressure is helpful if you use a Pressure Sensitive tablet for selections.
Hitting the Escape key aborts the Selection, but hitting the delete simply deletes your last point in your selection, allowing you to begin again with your last previous point. This is a very useful tip - you will use it frequently.
Here is an image of a tombstone I wish to select
Here is the image after using the Magnetic Lasso Tool very quickly selecting the rough outline of the stone.
Notice the grass included along the top and bottom of the selection and the error on the right side of the stone. Just a few moments with the Magic Wand Tool in the Blue Channel accomplished this
Notice how the grass along the bottom and top of the stone are now subtracted from the selection? I also use the Lasso Tool at a high magnification of 200% to walk around the edge of the image using the Lasso Tool while holding down the Shift or Alt Keys adding or subtracting from my selection as needed to finally complete my selection.
Now I can alter the selected area to my heart’s content - It can be sharpened and turned purple, without affecting the grass along the bottom of the stone.
HITTING THE CAPS LOCK KEY, changes the Magnetic Lasso cursor to a circle with a cross-hair in the center that helps center your line of selection and identifies how far afield the Width Settings is looking for contrast to select. This is another great tip!
Use higher Width and Edge Contrast settings on images with more clearly defined images, and lower values for lower contrast less clearly defined images.
Pressing the right and left bracket keys - [ or ] - makes the cursor increase or decrease one pixel, just as it does with the Brush tool. Pressing Shift+[ or Shift +], changes the cursor size by 10 pixels.
Again, pressing the Escape Key aborts the selection and removes the line and dots, but the Delete Key only deletes that last most point selected by the Magnetic Lasso Tool.
SELECTION ultimately is made by using a series of tools that initially begin a rough selection and gradually refine the selection by adding or subtracting elements , by using other alternative tools as needed. I use the Magnetic Lasso and the Color Select Command, and the Polygonal Lasso quite frequently. The Marquee tools I use less for selection for editing images, but more for creating vignettes and gradients for editing.
The author begins by stating that there are usually three to five ways of accomplishing anything in Photoshop. The longer I work with and learn PS, the more verity I discover in her statement. In other words, we need to know more than one way to skin a cat, or make a selection in an image.
Chapter 2 will teach us how Photoshop creates selections from our inputs. We will learn how to analyze an image to create the easiest path to a selection. We will learn about the Marquee, Elliptical, Lasso tools, and the Magic Wand and the Quick Mask mode. And the value of combining more than one tool or technique to accomplish our selections.
What on Earth is a Selection, ANYWAY!!??
You can edit an image either one of two ways, Globally OR Locally. A Global edit is a change that is applied uniformly to the whole image - like a Photo Filter for example, found by typing Image>Adjustments>Photo Filter which then brings up this box
Here is an image of an egret of mine
Here is the image after a global filter with the Photo Filter command of the 85A warming filter at 75% to the whole image - notice the change in color of all of the bird and the sky
And here is the filter applied LOCALLY to the bird ONLY, that I selected by using the Color Select Command
Notice how the bird’s white feathers have been warmed, but the sky and the beak have not been changed because the effect was applied to ONLY the LOCAL selection. Here is the local selection complete with the marching ants displayed
So local selections can be useful things to know how to do. But what are they really, in Photoshop??
When you make a selection in PS using any of the typical selection tools, the selection is outlined by “Marching Ants” - a series of blinking dashes, but Photoshop does not see things that way.
Photoshop actually references parts of the image to an active or an inactive area in the grey scale layers of the image. Selected areas are WHITE, and Deselected areas are Black.
So the area inside the “Marching Ants” is White or active, and the area outside your selection is Black or inactive. The dividing line between selected and non-selected can be a sharp black line or a faded grey gradient depending on how you set up your selection tools with the Feather command.
A Feather of ‘0’ will give a very sharp border, but a feather of 10 may create a soft border on a small image with just a few pixels, or a sharper border on a larger image with lots of Megapixels. So try to think of your selections inside the marching ants as a white image on a black background, because that is how Photoshop will display it later when you get to Quick Masks.
The author then spends a little time discussing Shape and Form and how they can be used to decide which Selection tools to utilize. Shape selections are usually geometric - squares, circles, rectangle, polygons etc - and are usually manmade. Forms are more organic structures with smooth edges and flowing contours.
Tone and Color can also be used for selections, as I did with the egret images above. Some times it is easier to select what you do not want, and then Invert the selection with the Invert command in PS. That is how I selected the egret - I selected the blue sky and then Inverted the selection.
Edges and Fine Detail like wisps of hair give most Photoshop editors the willies. Soft edged images like moving automobiles or blurred out of focus images are other details that can challenge your selecting skills. As are Translucency and Light and wisps of smoke.
Geometric Shape Selections
The Marquee, Polygon Lasso and Pen tools are the tools for Geometric selecting. It would be tedious indeed to try outlining the feathers in the egret I posted with any of the geometric tools. The Pen tool deserves its own chapter, and will be covered in detail in Chapter 3.
The Marquee tool can be found in the Tools palette on the upper left side
Outlining the Prestolite sign in this image should be rather easy.
.
The Polygon selection tool will select it with 4 quick clicks. Or the Marquee tool can select it with a click and a drag of the mouse. The round wheel could be selected by the Marquee tool, by pressing the [Option and Shift] keys while dragging with the mouse from the center.
The author then goes on and spends four pages describing the various modalities and key strokes of the Marquee tool and the Polygon tool. For example, to select a perfect square, hold the SHIFT key while dragging the Rectangular or Elliptical marquee tool. Press the Option or Alt key to start from the center point.
I am not going to describe in detail each and every keystroke needed to use the Marquee and Polygon Lasso tools as they need to be practiced and used until they become second nature. I urge the reader to spend the time learning the keystrokes required to use the Rectangular and Elliptical selection tools.
I find I use the Polygonal Selection tool much more frequently as the selections from photographic images are usually not perfect squares or rectangle or circles, but more polygonal shapes that I can walk around clicking the Polygonal selection tool as I go to gather the form.
If you click outside of your selection, you are beginning a new selection, and have discarded the old selection. The key board manner of discarding your selection is [ctrl+D] or [command+d] on the Mac.
The author describes a neat way of selecting circles and ovals without guesswork. Select View>Show Rulers. Drag out four guides that just touch the edge of the needed selection. With the Elliptical Marquee tool, click the upper left corner of the intersection of the guides and drag to the lower-right intersection of the guides. If necessary, you may need to use the Select>Select Transform to scale and shape the selection outline.
Selection tool Options
When using a tool, it is a good idea to inspect the tool bar at the top of the screen to verify the setting of the tool utilized.
Feather
Feathering softens the edges of a selection to both the inside and the outside of the initial selection. Feathering creates a gradient in the grayscale image that represents the area of selection. The author goes on the say that she does not recommend using a Feather amount in the Options bar, because you cannot see the results of the feathering with the selection tool. She recommends using the Gaussian blur tool in the Quick Mask mode so that you can visually see the effect on the Mask, which she will discuss further in Chapter 3.
Anti-Aliasing
Its best to leave Anti-Aliasing on unless you know why you want to turn it off, for example, tiny icons for the WEB or graphical drawing created by an artist.
Style
When the Rectangular or Elliptical Marquee tool is active, you can choose three different styles of actions. Normal, or Constrained Aspect Ratio, and Fixed Size.
Normal style lets you make a rectangle of any size you wish. Constrain Aspect ratio lets you specify the ratio between the height and width of the rectangle, 1 to 1 would be a perfect square. A ratio of 2 height by 3 width will create a perfect 35mm aspect ratio of 24 by 36 mm. Fixed size is very useful as it allows you to specify a final image size such as 4 by 5 inches that will match standard 8x10 printing paper.
Selecting Non-Geometric Shape-Based Subjects
Not all shapes are perfect squares or rectangles as I mentioned earlier. The Polygon Lasso tool and the Pen Tool are very useful in these situations.
The Polygon tool makes perfectly straight lines between clicks of the mouse. When your selection is competed, double clicking the end where you began competes the selection and starts the marching ants, or you can hit the Return Key..
The author suggests using the Polygon Tool on the image at its full size by hitting [ctrl+0(zero key)+Alt] or Command+Option+0 on the Mac which brings up the image at 100% size. For more detail hit command and the plus key simultaneously, to step up the magnification. Hit command and the minus key simultaneously to reduce the image magnification.
If you run out of space on the screen, press and hold the space bar and the selection tool transforms to the Hand tool which lets you grab the image and move it around as needed. After an initial selection with the Polygon tool, you will need to inspect the edges of the selection at higher magnification and use the Lasso tool to free hand add or subtract from your selection. Holding down the shift key adds to your selection if you begin in the area already selected. Holding down the alt/option key subtracts the selection from your already selected area. Once the selection is complete it can be copied and pasted with ctrl-C and ctrl-V. It can be moved in the image by holding down the V key. And best of all, it can be saved as an Alpha channel if the file is saved as a PSD or a TiFF.
Form Based Selections
The Standard Lasso tool lets you select objects that are organically shaped without straight lines. Click and hold the mouse button down to let you draw like a pen around the object selected. You can turn the Lasso tool into the Polygon tool by Option-clicking (Alt-clicking) your way around an objects using straight lines and then back to curved lines again with the Lasso tool. Again the reader needs to spend some time practicing using the Lasso and the Polygon tool making selections until they are second nature. This is more like riding a bicycle than thinking in some ways.
Adding, Subtracting, and Intersecting Selections
Moving your selection tool inside your selection changes the appearance of the tool to a rectangle with an arrow pointing to it. If it is outside your selection, your selection tool remains unchanged.
If you want to add and area to your selection, hold down the Shift Key and draw from your selection to the area outside that needs to be included. If you want to exclude an area, hold down the option/alt key to remove part of your selection beginning from within the selection.
Intersecting with a Selection
You can begin a selection with the Magic Wand and then use the Marquee tool to choose a smaller rectangular area of the first selection. When using the Marquee or Lasso tools to add, subtract, or intersect a selection, be sure that the feather amount in the Options bar is the same, or the edges of your selections will vary, and look funky as a result.
Color and Tone Selections
There are three tools useful for selecting on the basis of color. The Magic Wand tool, the Magnetic Lasso Tool, and the Color Select Command.
The Magic Wand tool
The Magic Wand is a quick tool for selecting when the background is a uniform color that is not in the area of selection. Unfortunately, in real world photographs this rarely happens. The Magic wand tool can be used if the subject stands out clearly a different color than the background. There are four settings for the Magic Wand Tool, Tolerance, Contiguous, Use All Layers, and the Sample Size for the Eye Dropper Tool.
The Tolerance setting sets the range of brightness levels from 1 to 255 that it allows. Although it is called the Magic Wand, it really selects ranges of Brightness, instead of color, as the Magic Wand does not really look at Color, but only Brightness levels. (Maybe it would work better in the Lightness Channel of LAB ?? as there is little variation in the A and B channels there)
The Magic Wand selects based on an average reading of all three channels in RGB or four channels in CMYK, which makes the Wands performance difficult to predict sometimes. It works well sometimes, but awful at others. As a result, the author suggest inspecting each of the three RBG channels, and finding the channel with the greatest contrast in the area of the needed selection to make the selection with the Magic Wand in that channel. This is a really good tip!! After selecting in the Red channel for instance as in the book, she then types [Cmd+~] or [Ctrl+~} to review the composite three channel color image again.
Again she suggests leaving anti-aliasing on at all times, unless selecting flat graphic colors from a drawing rather than a photograph.
Contiguous is on by default, and means that the color/tonality must be in contact - contiguous - throughout the area of selection. Turning Contiguous OFF, means that the selected color will be picked through out the whole image - Globally.
Use ALL Layers determines whether the Magic Wand uses only the visible layer or the whole stack of layers of the document. This can be helpful in selecting a particular tone that exists on multiple layers.
The Sample Size of the EYE DROPPER Tool helps determine how large the area the Magic Wand uses for its calculations. The 3x3 eye dropper size seems to work better than a single pixel which can be unintended chosen poorly and not represent what you thought you were choosing.
The Magnetic Lasso Tool
The Magnetic Lasso is a tool that gets used a lot, sometimes for quick and dirty trial runs, and sometimes for detailed work. It is easier to use than the Lasso or Polygon Lasso tool also.
To use the Magnetic Lasso tool, start with an area of sharp contrast in your image and click the mouse button. The Magnetic Lasso will enter a point on the image and then lay down a line of marching ants that tend to follow the line of contrast established by your first click. Then keep the cursor where you want the selection to be and click as you gradually move along and the Magnetic Wand will lay down a series of dots and lines following your cursor path, even if you are a little off the actual track in the image. It tends to follow the area of contrast that you identify when you click each time on the selection.
The Feather and Anti-Aliasing works as with the other selection tools.
Width tells the Magnetic Lasso how far from its center point (from 1-40 pixels) to detect an image contrast line. Use lower settings to increase the precision, and prevent the tool from selecting areas nears your selection that might be similar in contrast.
Edge Contrast constrains the Magnetic Lasso to look for a minimum degree of contrast between the selection and the background. Use higher settings >30% for images that are quite different from the background, and lower settings for low contrast images.
Frequency determines the rate at which points are anchored by the Magnetic Lasso tool. The higher the frequency, the faster points are put down. For simple smooth lines lower frequency may be adequate, but for complex images, higher frequencies may be more useful.
Style Pressure is helpful if you use a Pressure Sensitive tablet for selections.
Hitting the Escape key aborts the Selection, but hitting the delete simply deletes your last point in your selection, allowing you to begin again with your last previous point. This is a very useful tip - you will use it frequently.
Here is an image of a tombstone I wish to select
Here is the image after using the Magnetic Lasso Tool very quickly selecting the rough outline of the stone.
Notice the grass included along the top and bottom of the selection and the error on the right side of the stone. Just a few moments with the Magic Wand Tool in the Blue Channel accomplished this
Notice how the grass along the bottom and top of the stone are now subtracted from the selection? I also use the Lasso Tool at a high magnification of 200% to walk around the edge of the image using the Lasso Tool while holding down the Shift or Alt Keys adding or subtracting from my selection as needed to finally complete my selection.
Now I can alter the selected area to my heart’s content - It can be sharpened and turned purple, without affecting the grass along the bottom of the stone.
HITTING THE CAPS LOCK KEY, changes the Magnetic Lasso cursor to a circle with a cross-hair in the center that helps center your line of selection and identifies how far afield the Width Settings is looking for contrast to select. This is another great tip!
Use higher Width and Edge Contrast settings on images with more clearly defined images, and lower values for lower contrast less clearly defined images.
Pressing the right and left bracket keys - [ or ] - makes the cursor increase or decrease one pixel, just as it does with the Brush tool. Pressing Shift+[ or Shift +], changes the cursor size by 10 pixels.
Again, pressing the Escape Key aborts the selection and removes the line and dots, but the Delete Key only deletes that last most point selected by the Magnetic Lasso Tool.
SELECTION ultimately is made by using a series of tools that initially begin a rough selection and gradually refine the selection by adding or subtracting elements , by using other alternative tools as needed. I use the Magnetic Lasso and the Color Select Command, and the Polygonal Lasso quite frequently. The Marquee tools I use less for selection for editing images, but more for creating vignettes and gradients for editing.
Pathfinder - www.pathfinder.smugmug.com
Moderator of the Technique Forum and Finishing School on Dgrin
Moderator of the Technique Forum and Finishing School on Dgrin
0
Comments
Working with Quick Mask
Quick Mask is really the power behind the selection tools. Quick Mask lets you easily see the areas selected in White, and the areas not selected in Black. Any areas of translucency or gradients are displayed as a fading grey line of transition.
Before beginning with Quick Mask Mode, you must bring up the Quick Mask Mode dialogue box to make certain it is configured correctly. Press the QM Dialogue Box button in the Tool Palette well as shown here
And you should see the following box...
Make sure your radio buttons are as shown. Then, when you have a selection done complete with ‘marching ants’, and you type “q”, you should see the following
The area selected is clearly seen, and the area NOT selected is in red. The color indicating the area NOT chosen can be changed in the QM dialogue box shown above. Now, we can paint on this mask with a brush set to NORMAL mode, and with black ink, to further remove parts from your selection, or with a white brush to add to your selection. The brush with Black ink will seem to lay paint with red ink in this selection mode of Quick Mask.
When you are done editing your mask, hitting ‘q’ again will revert you back to your image with the selection outlined in ‘marching ants’ again. The author suggests always checking your selections in the Quick Mask mode before finally accepting the selection as correct to help identify areas that might not have been noticed as selected or not selected in error.
Here is the Quick Mask mode of the rough version of my selection of the tombstone
You can see the smooth edge along the bottom where the grass was not yet removed from my mask.
Here is the Channel Palette displaying the Mask by clicking on the EYE of the RGB channels and turning them off to show only the MASK image as a a grayscale image as seen above.
Some times there are small bits and pieces included where they should not be, like dirt or small areas of color deselected within the area of selection that were the color of the surrounding area. These can be painted over or removed by applying a Dust &Scratches Filter from the Drop Down Filter Menu. I generally prefer to just paint over them with the White brush to paint them into my accepted area of the mask.
Starting Without A Selection
For the artists among us, who prefer to do their selections freehand, the Quick Mask mode offers the ability to paint in and out your selections directly. Open the Quick Mask Mode dialogue box, and switch the buttons as shown here.
Note that the radio buttons now show Selected Areas as pushed, and the color has been altered by clicking on the colored box directly and then choosing a new color when the Color Picker Box pops up as a result of the click on the colored box.
Now, the artists among us ( You Know Who You Are:): ) can paint with a white or a black colored brush in Normal Mode and select areas in black, and deselect areas in white ( the areas selected button was pushed this time, remember??).
Myself and the rest of us non-artists, will continue to use the Magic Wand, the Magnetic Lasso, and all the other selection tools that Photoshop has provided for us.
A Final Note from Pathfinder
There is no way to just read chapter 2 and learn these skills.
You will need to spend the time making selections and learning the KEY commands down cold.
The Key commands seem daunting to beginners in PS, who find the menus easier to understand at first. But speed will only come when the KEY commands are in your blood and in your fingers, and you can make these selections without the menu commands.
The KEY shortcuts are the real secret weapon of the Photoshop gurus, and for me at least, I only learn them by doing them over and over and over, until they are second nature to my fingers. This then frees my mind to think about the image I am trying to improve.
I am still learning new ways to skin a cat and select portions of my images better, thanks to Katrin Eismann and Chapter 2.
Moderator of the Technique Forum and Finishing School on Dgrin
Awesome writeup. Thanks for doing this. It adds so much to the writeup when you take your own shots and show us examples of what's being discussed. I know that takes a lot of extra time to do, so thanks for doing that.
I've linked in your writeup to the master chapter listing too.
Homepage • Popular
JFriend's javascript customizations • Secrets for getting fast answers on Dgrin
Always include a link to your site when posting a question
Moderator of the Technique Forum and Finishing School on Dgrin
Real Body Integrated Arts
GMT -5