Friday, 21 December 2007
Selections Using Photoshop
Selections are areas within the canvas that you set apart from the rest of the canvas. You can apply special effects to these areas or other wise modify, copy, cut, flip, move, rotate or scale them.
It is important to understand that Photoshop is different from other programs in which you select things. Typical reasons to make selections include:
• Editing a portion of your canvas
• Creating a mask or layer
• Cropping
• Applying filters and special effects to portions of your image
To select a portion of your canvas, you will have to use one of the selection tools that we will look at later. But all selection tools do the same basic task, they draw an outline around some bit of your canvas with a little flashy marquee that looks like a dashed line or a row of little parading ants.
Once you have selected an area, you can manipulate that area in many cool ways. We will do a lot of manipulation of selections over today and tomorrow, so it is crucial that we get a good sense of how to select areas.
Modifying a Selection
Deselecting a selection Click outside
We will talk about several tools to make an initial selection however we should mention here that all selections share several properties.
To add to a selection
Hold down the SHIFT key and use the selection tool to add to the existing outline.
To subtract from a selection
Hold down the OPTION or ALT key and use the selection tool to remove from the existing selection.
To create an intersection selection
Hold down the ALT and SHIFT and use a selection tool to deselect all but the overlapping portions of two selections.
SELECT Menu
There are also several built in selection modification tools in the SELECT menu item. These include Grow, Similar, Border, Smooth, and Expand/Contract. These all modify the selection in predefined ways.
Grow
includes all adjacent pixels falling within the tolerance range specified in the magic wand options.
Similar
include pixels throughout the image, not just adjacent ones, falling within the tolerance range.
Border
creates an anti-aliased selection. To paint a hard-edged border around a selection
Smooth
cleans up stray pixels left inside or outside a color-based selection
Expand
Increases the selection
Contract
Decreases the selection
The Marquee Tool - The list of tools that you can use to create selections.
The Marquee tool is the most basic of selection tools and often the one most useful. This tool is used to draw selections based on geometric shapes. Specifically, the marquee tool allows you to draw rectangular and elliptical selections. To form the selection, simply click and drag the mouse.
You can easily choose the geometrical form by changing the value for Shape in the options palette. A fast way to access the Marquee tool is the "M" key. The "M" also allows you to cycle between the rectangle and the ellipse
• get a square from a rectangular marquee or a circle from an elliptical marquee, simply hold the SHIFT key while you drag out your selection
• press and. use the EDIT --> FILL or EDIT -->STROKE menu item to either fill or outline the shape.
• To draw the selection out from the center, press and hold the ALT key while dragging out the selection.
• to anti-alias your selection, you can use the Anti-alias checkbox or the Feather checkbox or both. The feathering checkbox simply affords an extra degree of anti-aliasing.
The Lasso Tool
The Marquee tool is certainly cool and when you use the SHIFT and ALT keys to add or subtract from the selection, you can create some pretty complex selections. However, often times, a free form selection tool is what you really want. A freeform tool like the Lasso, allows you to draw out a selection area much like you were tracing over an image through tracing paper.
To create a free form selection, simply choose the Lasso tool and click and drag on the canvas. The selection will follow your drag. Obviously, it is unlikely that you will succeed in making a free form selection right the first time since it is very easy for your mouse to slip. Fortunately, you can use the SHIFT and ALT keys to add or subtract from a selection as well as use the ALT key down while you drag with the Lasso to create polygons much like you would do to create lines using one of the paint tools
Note that if you do not perfectly align up the beginning and the ending of a lasso selection, Photoshop will complete it for you by drawing a line from the end to the beginning as the crow flies.
The Magic Wand Tool
I wanted to select the black area in the sample above. "Lasso Select" would have been too tedious and time consuming. The "Magic Wand" is the tool of choice here. With the right settings, the "Magic Wand" tool can select a complex area with just one click. I played around with different Tolerance settings.
The Move Tool
The Move Tool is quite handy indeed. This tool allows you to take any selection and move it to a different location on the canvas. It is also very easy to use. Simply click and hold on the selection and then drag the mouse to move the selection.
Note
You can also move a selection pixel by pixel by using the arrow keys. this gives more precisemovement but is less convenient for large moves. Note also that you can get the exact screen positions by looking at the info palette.
The Crop Tool
The cropping tool does exactly what you would expect, it crops out a rectangular portion of your canvas and throws away the pixels outside the crop. To create a crop marquee, simply select the Crop Tool, click on the canvas and drag out an area.
It is important to understand that Photoshop is different from other programs in which you select things. Typical reasons to make selections include:
• Editing a portion of your canvas
• Creating a mask or layer
• Cropping
• Applying filters and special effects to portions of your image
To select a portion of your canvas, you will have to use one of the selection tools that we will look at later. But all selection tools do the same basic task, they draw an outline around some bit of your canvas with a little flashy marquee that looks like a dashed line or a row of little parading ants.
Once you have selected an area, you can manipulate that area in many cool ways. We will do a lot of manipulation of selections over today and tomorrow, so it is crucial that we get a good sense of how to select areas.
Modifying a Selection
Deselecting a selection Click outside
We will talk about several tools to make an initial selection however we should mention here that all selections share several properties.
To add to a selection
Hold down the SHIFT key and use the selection tool to add to the existing outline.
To subtract from a selection
Hold down the OPTION or ALT key and use the selection tool to remove from the existing selection.
To create an intersection selection
Hold down the ALT and SHIFT and use a selection tool to deselect all but the overlapping portions of two selections.
SELECT Menu
There are also several built in selection modification tools in the SELECT menu item. These include Grow, Similar, Border, Smooth, and Expand/Contract. These all modify the selection in predefined ways.
Grow
includes all adjacent pixels falling within the tolerance range specified in the magic wand options.
Similar
include pixels throughout the image, not just adjacent ones, falling within the tolerance range.
Border
creates an anti-aliased selection. To paint a hard-edged border around a selection
Smooth
cleans up stray pixels left inside or outside a color-based selection
Expand
Increases the selection
Contract
Decreases the selection
The Marquee Tool - The list of tools that you can use to create selections.
The Marquee tool is the most basic of selection tools and often the one most useful. This tool is used to draw selections based on geometric shapes. Specifically, the marquee tool allows you to draw rectangular and elliptical selections. To form the selection, simply click and drag the mouse.
You can easily choose the geometrical form by changing the value for Shape in the options palette. A fast way to access the Marquee tool is the "M" key. The "M" also allows you to cycle between the rectangle and the ellipse
• get a square from a rectangular marquee or a circle from an elliptical marquee, simply hold the SHIFT key while you drag out your selection
• press and. use the EDIT --> FILL or EDIT -->STROKE menu item to either fill or outline the shape.
• To draw the selection out from the center, press and hold the ALT key while dragging out the selection.
• to anti-alias your selection, you can use the Anti-alias checkbox or the Feather checkbox or both. The feathering checkbox simply affords an extra degree of anti-aliasing.
The Lasso Tool
The Marquee tool is certainly cool and when you use the SHIFT and ALT keys to add or subtract from the selection, you can create some pretty complex selections. However, often times, a free form selection tool is what you really want. A freeform tool like the Lasso, allows you to draw out a selection area much like you were tracing over an image through tracing paper.
To create a free form selection, simply choose the Lasso tool and click and drag on the canvas. The selection will follow your drag. Obviously, it is unlikely that you will succeed in making a free form selection right the first time since it is very easy for your mouse to slip. Fortunately, you can use the SHIFT and ALT keys to add or subtract from a selection as well as use the ALT key down while you drag with the Lasso to create polygons much like you would do to create lines using one of the paint tools
Note that if you do not perfectly align up the beginning and the ending of a lasso selection, Photoshop will complete it for you by drawing a line from the end to the beginning as the crow flies.
The Magic Wand Tool
I wanted to select the black area in the sample above. "Lasso Select" would have been too tedious and time consuming. The "Magic Wand" is the tool of choice here. With the right settings, the "Magic Wand" tool can select a complex area with just one click. I played around with different Tolerance settings.
The Move Tool
The Move Tool is quite handy indeed. This tool allows you to take any selection and move it to a different location on the canvas. It is also very easy to use. Simply click and hold on the selection and then drag the mouse to move the selection.
Note
You can also move a selection pixel by pixel by using the arrow keys. this gives more precisemovement but is less convenient for large moves. Note also that you can get the exact screen positions by looking at the info palette.
The Crop Tool
The cropping tool does exactly what you would expect, it crops out a rectangular portion of your canvas and throws away the pixels outside the crop. To create a crop marquee, simply select the Crop Tool, click on the canvas and drag out an area.
Using Adobe Photoshop CS Fundamentals
Adobe Photoshop is one of the most popular tools for digital image enhancement, photo retouching, and image composition.
NOTE: While creating or editing graphics in Photoshop, it is important to remain aware of the issues surrounding Intellectual Property, Copyright, and Fair Use Resources.
Adobe Photoshop is an image manipulation/production software, and is designed particularly for working with photo-based images. While you can certainly generate images from scratch, the Photoshop software is particularly useful for altering pre-existing digital images or scanned photo images. Today's introductory workshop will focus on pre-existing images.
Getting Started
In order to begin to familiarize ourselves with some of the basic operations of Photoshop we are going to open a practice image from the Samples,(that come with the software). First, open Adobe Photoshop under the Start menu in the lower left corner of the screen.
Under the pull-down File menu in Photoshop, choose Open.
In the dialogue box that pops up, the Samples folder should already be open with a list of available images.
Select an image to experiment with from those listed. Choose one that has a .psd or a .tif file extension.
In order to ready yourself to do some basic work with Photoshop you should make sure that the Tools and the Layers dialogue boxes, (pictured left), are visible.
In order to ready yourself to do some basic work with Photoshop you should make sure that the Tools and the Layers dialogue boxes, (pictured left), are visible.
If they are not visible, go to the pulldown Window menu at the top of the screen. Select Show Tools and Show Layers in that list. Click on them to make those tools available on screen.
In the Tool bar, (pictured above and to the left), the icon at the upper left that looks like a box made out of dashes, is the Linear Marquee tool. It is used to select portions of the image for cropping or copying. If you click once on the Linear Marquee icon box, it will pop out a row of other selection tools.
Click once on that tool, then position your mouse in the upper left corner of the image. Hold the mouse button down and use the cross that appears to draw a box around the area that you want to keep. Do this by holding the mouse button and dragging the mouse down and to the right. When you have finished selecting the area that you want to save, you will notice that if you point to the selection and hold the mouse button down you can reposition the selection by moving it around. You can also change its dimensions by placing the cursor, (or arrow), over any of the square handles on the box, holding the mouse button down, and dragging.
Try using the rectangular selection tool, (pictured below),
or the circular selection tool to select a portion of the image. Once it is selected, click Copy, and then Paste, under the pull-down Edit menu.
At first, you will not see the selection because it will be pasted directly over the portion of the image that you just copied.
To save your image
To save your image go to File, then Save As. Next, name your image and save it in the My Documents folder, (which should be visible in the pull-down Look in menu, in the Save As dialogue box). The default file extension will be .psd. This is what you want for now because it will preserve all the layers separately.
Layers Palette
Look at the Layers palette.
All of the layers are listed in hierarchical order. The one at the top is the foreground image, and those below are closest to the foreground in descending order. You can change the order of the layers, (i.e. what is in front and what is behind), by clicking on any layer + holding the mouse down + and dragging that layer up or down in the hierarchy.
You should see a background layer and any additional layers you have added when you were selecting and copying portions of your image. Those new layers will have generic names like Layer 1, and Layer 2.
NOTE: Remember that the selected layer will always be highlighted in dark blue. Any editing or changes you make on your images will only be applied to the layer that is selected at the time that you add those changes.
Naming the existing layers:
First let's name the existing layers:
Double click on Layer 1 to open a dialogue box:
Change the name from Layer 1 to something descriptive.
This is useful as your image grows so you can quickly identify each layer by just looking at the name.
Editing Layers
1. Or you can adjust the opacity of the layer by clicking on the arrow at the right of the opacity box in the Layers palette and sliding the fulcrum from right to left (and vice versa) to increase or decrease transparency.
2. You can move a layer closer to the foreground or the background of an image by clicking on it and dragging it up or down in the palette hierarchy.
3. You can delete a layer by dragging it into the trash can at the bottom of the palette. Wish you hadn't? Click Undo delete under the pulldown Edit menu
4. You can temporarily hide a layer by clicking on the eyeball to the left of the layer name in the palette.
Adding Text
Then click once on the image you are editing and this will open a dialogue box.
Click on the color box in the dialogue box in order to select a Text Color that will contrast with your image and be visible.
Type your text in the box.
Highlight the text so that when you choose different fonts or font sizes, those changes will be reflected.
Select a font, a font size and a type style (bold, italic etc.)
Select orientation for the text (center, left justified, right justified--these are selected using the icons that look like pages with lines of text on them). Also insert any line breaks in the text as you want them to appear on your image. Once you are satisfied with your font and size, click OK.
You can then use the move tool to reposition your text on your image.
Note that adding the text to your image has created a new layer and that the name of that layer is the contents of your text. If later you want to change that text, double click on the text in the text layer in the layers palette.
A Few Things about Colour
In your tool box you will notice at the bottom two color blocks. These are the foreground color (the one in front) and the background color.
The foreground color is the one that will be used when you use any of the painting or drawing tools in the toolbox or when you add text.
The background color will be picked up if you create a new image from scratch and you select Background Color as the color for your new image. (If you want to see this click on New under the pulldown File menu and note that, in the dialogue box, in addition to asking you for size info for the new image, the program will also allow you to choose whether the new image has a transparent background, a white background or whether it uses the background color from the toolbar).
To change the foreground (or the background) color in the toolbar you can double click on the foreground (or background) color box in the toolbar. This will open a color picker dialogue box in which you can select a shade by clicking anywhere in the color palette. Note that the hexadecimal # for that shade (which is what web pages use to specify colors) is shown at the bottom of the color picker dialogue box. It will look something like this: #FFOOOO
Once you have selected your colors you can switch them back and forth (swapping background for foreground and vice versa) by clicking on the little arrow in the upper right corner of the color selection box (pictured above).
You can also change the foreground or the background color using the eyedropper tool.
With this tool you can select a color from an image you have opened by clicking on any area in this image. That color you click on will become the foreground color in the toolbox (or the background color if you have selected to change the background--same process).
Once you have selected your colors you can switch them back and forth (swapping background for foreground and vice versa) by clicking on the little arrow in the upper right corner of the color selection box (pictured above).
You can also change the foreground or the background color using the eyedropper tool.
With this tool you can select a color from an image you have opened by clicking on any area in this image. That color you click on will become the foreground color in the toolbox (or the background color if you have selected to change the background--same process).
Drawing Tools & Brushes
In your toolbar you will notice some tools that look like paint brushes, pencils, etc. These can be used for creating new images or for editing existing images. Because it is somewhat difficult to draw freehand with a mouse, these tools are often best used as editing tools.
Under the pull-down Window menu select Show Brushes. This is the palette that will help you select the thickness and the strike style for the drawing and painting tools.
Pencil tool
Change the foreground color to black.
Select a small brush size from the Brushes palette.
Select the background layer in your image.
Use the Pencil tool to draw a black mark on your draw.
Magnifying glass
Click on the black mark with the Magnifying glass to zoom in on it.
Now select the eyedropper tool from the tool box:
Colour Picker
Click on the colored pixels adjacent to the black mark to select that color as the foreground color in the tool box.
Select the pencil tool again and this time write over the black mark with the adjacent color.
Eraser tool
If you like you can experiment now with some of the other brushes and with the eraser tool which will remove pixels from the image (like an eraser):
Image Size
Image size can be adjusted by using the pull down menu under Image.
Click on Image Size.
In the dialogue box you can adjust the image size by pixels or by percentage.
So, for example, if you know you want to reduce the image by half you can change the percentage from 100 to 50.
If you know that you want an image that is 300 pixels wide you can type that into the pixel width box and the height will automatically be adjusted.
It is a good idea to check the box that says Constrain Proportions so that if you adjust the height or the width the other will be adjusted automatically to maintain the aspect ratio of the image so it will not appear distorted. Remember its usually OK to shrink an image a little without interfering with the appearance--but if you shrink it or increase it too much, the quality may be noticeably reduced.
Filters
You can play with altering your image using filters under the pull-down Filter menu.
Again, if you add a filter and don't like it you can go to the Edit menu and click Undo to undo your LAST operation. Most filters will offer a preview of sorts.
Some Filters will ask you to render the text first--just click OK.
Remember that the filter will only be applied to the layer that is selected.
Save
You should first save a .psd version of your image because this will preserve all of the layers discretely so that you can further edit them.
After you do that, then, if you are creating this image for the Web choose Save for Web.
You can note the image size and the download time at this point (look in the lower left corner of the dialogue box) and if it seems too large, go back and make it smaller.
For the web,PNG JPG GIF are the preferred formats.
PNG is usually preferred for Flash and for images that contain transparent areas
JPG tends to produce a smaller file size (good for quick downloads) and is also preferable in general for photo-realistic or photo-based images.
GIF is usually preferred for simple drawings and for images that contain transparent areas
NOTE: While creating or editing graphics in Photoshop, it is important to remain aware of the issues surrounding Intellectual Property, Copyright, and Fair Use Resources.
Adobe Photoshop is an image manipulation/production software, and is designed particularly for working with photo-based images. While you can certainly generate images from scratch, the Photoshop software is particularly useful for altering pre-existing digital images or scanned photo images. Today's introductory workshop will focus on pre-existing images.
Getting Started
In order to begin to familiarize ourselves with some of the basic operations of Photoshop we are going to open a practice image from the Samples,(that come with the software). First, open Adobe Photoshop under the Start menu in the lower left corner of the screen.
Under the pull-down File menu in Photoshop, choose Open.
In the dialogue box that pops up, the Samples folder should already be open with a list of available images.
Select an image to experiment with from those listed. Choose one that has a .psd or a .tif file extension.
In order to ready yourself to do some basic work with Photoshop you should make sure that the Tools and the Layers dialogue boxes, (pictured left), are visible.
In order to ready yourself to do some basic work with Photoshop you should make sure that the Tools and the Layers dialogue boxes, (pictured left), are visible.
If they are not visible, go to the pulldown Window menu at the top of the screen. Select Show Tools and Show Layers in that list. Click on them to make those tools available on screen.
In the Tool bar, (pictured above and to the left), the icon at the upper left that looks like a box made out of dashes, is the Linear Marquee tool. It is used to select portions of the image for cropping or copying. If you click once on the Linear Marquee icon box, it will pop out a row of other selection tools.
Click once on that tool, then position your mouse in the upper left corner of the image. Hold the mouse button down and use the cross that appears to draw a box around the area that you want to keep. Do this by holding the mouse button and dragging the mouse down and to the right. When you have finished selecting the area that you want to save, you will notice that if you point to the selection and hold the mouse button down you can reposition the selection by moving it around. You can also change its dimensions by placing the cursor, (or arrow), over any of the square handles on the box, holding the mouse button down, and dragging.
Try using the rectangular selection tool, (pictured below),
or the circular selection tool to select a portion of the image. Once it is selected, click Copy, and then Paste, under the pull-down Edit menu.
At first, you will not see the selection because it will be pasted directly over the portion of the image that you just copied.
To save your image
To save your image go to File, then Save As. Next, name your image and save it in the My Documents folder, (which should be visible in the pull-down Look in menu, in the Save As dialogue box). The default file extension will be .psd. This is what you want for now because it will preserve all the layers separately.
Layers Palette
Look at the Layers palette.
All of the layers are listed in hierarchical order. The one at the top is the foreground image, and those below are closest to the foreground in descending order. You can change the order of the layers, (i.e. what is in front and what is behind), by clicking on any layer + holding the mouse down + and dragging that layer up or down in the hierarchy.
You should see a background layer and any additional layers you have added when you were selecting and copying portions of your image. Those new layers will have generic names like Layer 1, and Layer 2.
NOTE: Remember that the selected layer will always be highlighted in dark blue. Any editing or changes you make on your images will only be applied to the layer that is selected at the time that you add those changes.
Naming the existing layers:
First let's name the existing layers:
Double click on Layer 1 to open a dialogue box:
Change the name from Layer 1 to something descriptive.
This is useful as your image grows so you can quickly identify each layer by just looking at the name.
Editing Layers
1. Or you can adjust the opacity of the layer by clicking on the arrow at the right of the opacity box in the Layers palette and sliding the fulcrum from right to left (and vice versa) to increase or decrease transparency.
2. You can move a layer closer to the foreground or the background of an image by clicking on it and dragging it up or down in the palette hierarchy.
3. You can delete a layer by dragging it into the trash can at the bottom of the palette. Wish you hadn't? Click Undo delete under the pulldown Edit menu
4. You can temporarily hide a layer by clicking on the eyeball to the left of the layer name in the palette.
Adding Text
Then click once on the image you are editing and this will open a dialogue box.
Click on the color box in the dialogue box in order to select a Text Color that will contrast with your image and be visible.
Type your text in the box.
Highlight the text so that when you choose different fonts or font sizes, those changes will be reflected.
Select a font, a font size and a type style (bold, italic etc.)
Select orientation for the text (center, left justified, right justified--these are selected using the icons that look like pages with lines of text on them). Also insert any line breaks in the text as you want them to appear on your image. Once you are satisfied with your font and size, click OK.
You can then use the move tool to reposition your text on your image.
Note that adding the text to your image has created a new layer and that the name of that layer is the contents of your text. If later you want to change that text, double click on the text in the text layer in the layers palette.
A Few Things about Colour
In your tool box you will notice at the bottom two color blocks. These are the foreground color (the one in front) and the background color.
The foreground color is the one that will be used when you use any of the painting or drawing tools in the toolbox or when you add text.
The background color will be picked up if you create a new image from scratch and you select Background Color as the color for your new image. (If you want to see this click on New under the pulldown File menu and note that, in the dialogue box, in addition to asking you for size info for the new image, the program will also allow you to choose whether the new image has a transparent background, a white background or whether it uses the background color from the toolbar).
To change the foreground (or the background) color in the toolbar you can double click on the foreground (or background) color box in the toolbar. This will open a color picker dialogue box in which you can select a shade by clicking anywhere in the color palette. Note that the hexadecimal # for that shade (which is what web pages use to specify colors) is shown at the bottom of the color picker dialogue box. It will look something like this: #FFOOOO
Once you have selected your colors you can switch them back and forth (swapping background for foreground and vice versa) by clicking on the little arrow in the upper right corner of the color selection box (pictured above).
You can also change the foreground or the background color using the eyedropper tool.
With this tool you can select a color from an image you have opened by clicking on any area in this image. That color you click on will become the foreground color in the toolbox (or the background color if you have selected to change the background--same process).
Once you have selected your colors you can switch them back and forth (swapping background for foreground and vice versa) by clicking on the little arrow in the upper right corner of the color selection box (pictured above).
You can also change the foreground or the background color using the eyedropper tool.
With this tool you can select a color from an image you have opened by clicking on any area in this image. That color you click on will become the foreground color in the toolbox (or the background color if you have selected to change the background--same process).
Drawing Tools & Brushes
In your toolbar you will notice some tools that look like paint brushes, pencils, etc. These can be used for creating new images or for editing existing images. Because it is somewhat difficult to draw freehand with a mouse, these tools are often best used as editing tools.
Under the pull-down Window menu select Show Brushes. This is the palette that will help you select the thickness and the strike style for the drawing and painting tools.
Pencil tool
Change the foreground color to black.
Select a small brush size from the Brushes palette.
Select the background layer in your image.
Use the Pencil tool to draw a black mark on your draw.
Magnifying glass
Click on the black mark with the Magnifying glass to zoom in on it.
Now select the eyedropper tool from the tool box:
Colour Picker
Click on the colored pixels adjacent to the black mark to select that color as the foreground color in the tool box.
Select the pencil tool again and this time write over the black mark with the adjacent color.
Eraser tool
If you like you can experiment now with some of the other brushes and with the eraser tool which will remove pixels from the image (like an eraser):
Image Size
Image size can be adjusted by using the pull down menu under Image.
Click on Image Size.
In the dialogue box you can adjust the image size by pixels or by percentage.
So, for example, if you know you want to reduce the image by half you can change the percentage from 100 to 50.
If you know that you want an image that is 300 pixels wide you can type that into the pixel width box and the height will automatically be adjusted.
It is a good idea to check the box that says Constrain Proportions so that if you adjust the height or the width the other will be adjusted automatically to maintain the aspect ratio of the image so it will not appear distorted. Remember its usually OK to shrink an image a little without interfering with the appearance--but if you shrink it or increase it too much, the quality may be noticeably reduced.
Filters
You can play with altering your image using filters under the pull-down Filter menu.
Again, if you add a filter and don't like it you can go to the Edit menu and click Undo to undo your LAST operation. Most filters will offer a preview of sorts.
Some Filters will ask you to render the text first--just click OK.
Remember that the filter will only be applied to the layer that is selected.
Save
You should first save a .psd version of your image because this will preserve all of the layers discretely so that you can further edit them.
After you do that, then, if you are creating this image for the Web choose Save for Web.
You can note the image size and the download time at this point (look in the lower left corner of the dialogue box) and if it seems too large, go back and make it smaller.
For the web,PNG JPG GIF are the preferred formats.
PNG is usually preferred for Flash and for images that contain transparent areas
JPG tends to produce a smaller file size (good for quick downloads) and is also preferable in general for photo-realistic or photo-based images.
GIF is usually preferred for simple drawings and for images that contain transparent areas
Extracting a Complicated image using Channels in Photoshop
An RGB file starts with three channels: one each for red, green, and blue. Photoshop also displays a composite, one for all of the channels combined, although this composite isn't actually a channel itself. You can view and edit each channel individually, giving you total control over your image.
Now the trees are extracted from the background.
You use any tool, run any adjustment or effect on a channel.
Click ok.
Using the brush tool set to overlay paint over the trees to strengthen the contrast, notice that the white values are unaffected by the paint strokes.
Open the channels palette and pick the channel with the most contrast.
Duplicate the Channel by dragging down to the new channel icon.
Use levels to boost the contrast on the duplicated channel.
Click on the load selection icon or command click on the Green Channel. The image should now be selected. Choose select inverse. Return back to the layers palette. Now the dark pixels are selected.
Click on the layer mask icon at the bottom of the layers palette.
The Shapes Palette
The Shapes Palette
Adobe Photoshop makes it easy to add shapes to an image: you can draw them using a variety of shape tools, or select from a large assortment of predawn shapes. You can arrange vector shapes on separate layers for easy modification and overlay effects. In this tutorial, you'll add both background and foreground shapes to an image and create some flair with gradient and layer effects.
Click on the rectangle tool to reveal the shapes. To create a rectangle for example click and drag to create a rectangle covering the right half of the image. The rectangle uses the foreground color by default. To change the color, double-click the layer thumbnail to bring up the color picker and select a new color.
To create a custom shape select the custom shape tool
Since it's a vector shape on its own level, the sunburst is easy to move or resize. Select the layer and then use the Move tool to move the shape, or choose Edit > Free Transform to resize rotates, flip, or skew it.
Fill the custom shape with a pattern.
Next we'll apply one of Photoshop's pattern effects to make our shape more interesting. Select the new shape in the layers palette, and then choose Layer > Change Layer Content > Pattern. Click the pattern in the Pattern Fill dialog box to open the Patterns palette. Click the black triangle to open the palette menu.
The palette menu shows different sets of patterns--Artist Surfaces, Color Paper, Nature Patterns, and so on--that you can add to your basic patterns palette. Select a set, and then click Append. Click a pattern to apply it to the custom shape. To change your shape back to a solid color or to a gradient, choose the Layer > Change Layer Content command again.
Making your own shape library Making a Shape Path.
Select the pen tool which is next to the shape tool.
You can use a background image to trace around. This will automatically create a new shape layer. You should be able to turn down the opacity of the layer to see the trace properly and then turn it back up gain when you have finished. Turn off the background layer and there you have your custom shape.
To save your shape
Choose edit define custom shape, give it a descriptive name and click ok
Your new shape will now be in the shapes palette.
Adobe Photoshop makes it easy to add shapes to an image: you can draw them using a variety of shape tools, or select from a large assortment of predawn shapes. You can arrange vector shapes on separate layers for easy modification and overlay effects. In this tutorial, you'll add both background and foreground shapes to an image and create some flair with gradient and layer effects.
Click on the rectangle tool to reveal the shapes. To create a rectangle for example click and drag to create a rectangle covering the right half of the image. The rectangle uses the foreground color by default. To change the color, double-click the layer thumbnail to bring up the color picker and select a new color.
To create a custom shape select the custom shape tool
Since it's a vector shape on its own level, the sunburst is easy to move or resize. Select the layer and then use the Move tool to move the shape, or choose Edit > Free Transform to resize rotates, flip, or skew it.
Fill the custom shape with a pattern.
Next we'll apply one of Photoshop's pattern effects to make our shape more interesting. Select the new shape in the layers palette, and then choose Layer > Change Layer Content > Pattern. Click the pattern in the Pattern Fill dialog box to open the Patterns palette. Click the black triangle to open the palette menu.
The palette menu shows different sets of patterns--Artist Surfaces, Color Paper, Nature Patterns, and so on--that you can add to your basic patterns palette. Select a set, and then click Append. Click a pattern to apply it to the custom shape. To change your shape back to a solid color or to a gradient, choose the Layer > Change Layer Content command again.
Making your own shape library Making a Shape Path.
Select the pen tool which is next to the shape tool.
You can use a background image to trace around. This will automatically create a new shape layer. You should be able to turn down the opacity of the layer to see the trace properly and then turn it back up gain when you have finished. Turn off the background layer and there you have your custom shape.
To save your shape
Choose edit define custom shape, give it a descriptive name and click ok
Your new shape will now be in the shapes palette.
Friday, 12 January 2007
THE LAYERS PALETTE
The layers palette allows you to experiment freely with the different elements of an image until you decide on your final presentation and merge the layers.
Images with layers or with transparent backgrounds can only be saved in the photoshop file format.
You can have up to 100 layers if the computer has enough ram.
Layers allow you to make changes to an image without altering your original image data. For example, you might store photographs or elements of photographs on separate layers and then combine them into one composite image. Think of layers as sheets of acetate stacked one on top of the other. Where there is no image on a layer (that is, in places where the layer is transparent), you can see through to the layers below.
THE LAYERS PALETTE (WINDOW/SHOW LAYERS)
The layers palette lists all of the layers, a thumbnail image appears on the left and is updated as you edit it.
You can use the layers palette to CREATE, COPY, MERGE, HIDE, DISPLAY and DELETE layers. You can also create layer sets and change the viewing options.
Only one layer can be edited at a time, the active layer. Make a layer active by clicking on it's name in the layers palette, a paintbrush icon appears to the left and the layer name appears on the title bar of the image window.
SELECTING A LAYER
Click on the layer name in the layers palette OR Using the move tool (v), CONTROL-CLICK the element in the image window and choose it from the context layer which appears next to your cursor.
Thursday, 11 January 2007
Inputting images from typical sources into Photoshop
HOW SCANNERS WORK
Scanners operate by shining light at the object or document being digitized and directing the reflected light (usually through a series of mirrors and lenses) onto a photosensitive element. In most scanners, the sensing medium is an electronic, light-sensing integrated circuit known as a charged coupled device (CCD). Anything that can fit on a scanner can be scanned in and directly imported into Photoshop for manipulation.
HOW DIGITALCAMERAS WORK
The digital camera has all the same physical parts as the analogue camera, such as lens, shutter and focusing mechanism, but rather than simply having film to react to the light that makes up the image, the camera must have internally all of the electronics necessary to capture the light and change it into a digital image file. In most cameras, the sensing medium is an electronic, light-sensing integrated circuit known as a charged coupled device (CCD). Cameras are connected to a computer and opened in Photoshop for manipulation.
HOW DIGITAL DRAWING TABLETS WORK
The tablet consists of two parts, a flat surface for drawing, and a pen that is programmed to work with the tablet surface. Artists and illustrators use this as an ergonomic method of input into Photoshop
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