This document provides an introduction and overview of key concepts in Photoshop including: - Photoshop allows editing of raster graphics and was created in 1988. - There are two main graphic types: bitmap images made of pixels and vector images made of geometric objects. - Photoshop has selection tools like the marquee, lasso, and magic wand to select parts of an image for editing. - Images can be transformed by resizing, rotating, flipping, skewing, and distorting selections. - Layers allow stacking images and selectively editing their content.

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Photoshop 7.0
Introduction
Adobe Photoshop, or simply Photoshop, is a graphics editor. Adobe Photoshop is a
raster graphics editor developed and published by Adobe Systems for macOS and
Windows. Photoshop was created in 1988 by Thomas and John Knoll.
Computer Graphics Types
Computer graphics is a sub-field of computer science and is concerned with digitally
synthesizing and manipulating visual content. Although the term often refers to
three-dimensional computer graphics, it also encompasses two-dimensional
graphics and image processing. Computer graphics is often differentiated from the
field of visualization, although the two have many similarities.
Bitmap Graphic: - A bitmap image is one of the two major graphic types. Bitmap-
based images are comprised of pixels in a grid. Each pixel or "bit" in the image
contains information about the color to be displayed. Bitmap images have a fixed
resolution and cannot be resized without losing image quality. Common bitmap-
based formats are JPEG, GIF, TIFF, PNG, PICT, and BMP.
Vector Graphic: - Vector graphics is also called geometric modelling or object-
oriented graphics and it is all about the use of geometrical primitives such as points,
lines, curves, and polygons, which are all based upon mathematical equations to
represent images in computer graphics.
RESOLUTION: - In computers, resolution is the number of pixels (individual points
of color) contained on a display monitor, expressed in terms of the number of pixels
on the horizontal axis and the number on the vertical axis. The sharpness of the
image on a display depends on the resolution and the size of the monitor.
SELECTING IMAGES
Selections are the areas within the canvas that you set apart from the rest on which
you can apply special effects to or otherwise modify, copy, cut, flip, move, rotate or
scale. It is important to understand that Photoshop is different from other programs
in which you select things.
Marquee Tool
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.

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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, many 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 tool the canvas. The selection will follow
your drag.
Magic Wand Tool
This tool allows you to create a selection just by clicking on Magic Wand icon and
then clicking on the canvas. The selected area is created by adding all adjacent
similarly colored pixels to the selection. The range of hues selected is controlled by
the “Tolerance” level. The Larger the tolerance, the more shades of the color will be
selected.
MODIFYING SELECTION
Whenever we complete our selection we can modify the selected area. There are
certain modifications that we can do but some of them that we normally do are:
➢ Smoothing
➢ Condensing
➢ Expanding
➢ Cutting
➢ Copying
➢ Moving
➢ Cropping
TRANSFORMING IMAGES
Image transformation is an art to fit an image in such a format that is required. As
sometimes we get an image that is not of desired size, shape and resolution. There
we need the transforming of images. There are certain tasks that we can do in
transforming such as:
❖ Resizing
❖ Rotating
❖ Flipping
❖ Skewing

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❖ Distorting
❖ Changing perspective of selections
RESIZING IMAGES
In Photoshop we can change the size of the size of the image according to our
needs. Steps required to resized the image are as follows:
Step 1. Open the image file that to be resized.
Step 2. Select the option of Image → Image Size
Step 3. Select the unit of measurement from the list.
Step 4. Enter the width and height of the picture.
ROTATING IMAGES
Photoshop allows us to rotate an image with respect to a reference point, rotate an
image we have to specify the angle of rotation.
FREE TRANSFORM
Using this option we can resize and rotate the selected are from the image.
Following step are to be followed :
Step 1. Select an area from the image.
Step 2. Select the option of Edit → Free Transform from menu bar.
Step 3. Apply the desired action on the selected area.
Step 4. Press Enter key to apply the changes.
The Gradient Tool
The Gradient tool allows you to specify a gradient of color. Using it is fairly easy, you
simply choose the gradient tool from the toolbox and click on the canvas and drag
out an area to fill with the gradient.
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.
COLOR MODELS
A color mode determines the color model used to display and print images.
Photoshop bases its color modes on established models for describing and

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reproducing color. Common models include HSB (hue, saturation, brightness); RGB
(red, green, blue).
HSB Model
Based on HSB stands for HUE, SATURATION and BRIGHTNESS. human
perception of color, the HSB model describes three fundamental characteristics of
color:
• Hue is the color reflected from or transmitted through an object. It is measured
as a location on the standard color wheel, expressed as a degree between 0°
and 360°. In common use, hue is identified by the name of the color such as
red, orange, or green.
• Saturation, sometimes called chroma, is the strength or purity of the color.
Saturation represents the amount of gray in proportion to the hi measured as a
percentage from 0% (gray) to 100% (fully saturated). On the standard color
wheel, saturation increases from the center to the edge.
• Brightness is the relative lightness or darkness of the color, usually measured
as a percentage from 0%(black) to 100%(white).
RGB Model
A large percentage of the visible spectrum can be represented by mixing red, green,
and blue (RGB) colored light in various proportions and intensities.
CYMK Model
The CMYK model is based on the light-absorbing quality of ink printed paper. As
white light strikes translucent inks, certain visible wavelengths are absorbed while
others are reflected back to your eyes. In theory, pure cyan (C) magenta (M), and
yellow (Y) pigments should combine to absorb all light an produce black. For this
reason these colors are called subtractive colors.
PAINTING AND DRAWING TOOLS
In Photoshop, you can use the Paint Tools to draw freehand and to create your own
images and graphics. Photoshop's paint tools consist of the Pencil tool, the
Paintbrush, the Airbrush, and the Paint Bucket.
Using Painting Tools

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Painting with Brush:- Photoshop uses the generic term "brush" to represent any of
the drawing tools. Thus, the "paint brush" tool will have a brush. Actually, it helps to
think of a brush as the "drawing edge" of whatever drawing tool you are using.
Using Eraser
The eraser tool is a particularly intuitive tool. Click on the eraser icon and then click
on an area on the canvas and while holding the mouse button down, start dragging
the cursor around the canvas. You will quickly see why they call it the eraser tool, it
erases.
Magic Eraser
The magic eraser tool is a combination of eraser tool and magic wand tool. It just
erases the pixels with similar color values to that pixel, where the mouse has been
clicked on the image. The use clicks on the image area and similar pixels are erased
as per the opacity of the too. Opacity means strength of erasing.
Using Air Brush
The airbrush works a lot like the paintbrush except that it continues to apply paint as
long as the mouse button. Actually, with the exception of the Pressure slider, the
options for airbrush are the same as for paintbrush.
Using Pencil
To use the pencil tool, simply select it from the toolbar by depressing the pencil tool
icon. When you do so, you can draw on the canvas. However, the pencil tool also
has several options which are not generic modifications as well.
Using Paint Bucket Tool
The paint bucket tool is another very useful tool. To use the paint bucket tool, simply
click on the pouring paint bucket icon in the toolbox.
LAYERS
A layer is simply one image stacked on top of another. Imagine we have a piece of
paper and we paint it red. Then we take a piece of clear cellophane and paint a
yellow circle, and lay it over the paper.
Layers Palette

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The Layers palette is used to control our layer. It may be for creating, adding
deleting, hiding, and showing. The small versions of our images on the left of the
palette are called thumbnails. Each of these small rectangles represent a separate
layer.
Background Layer
When we create a new image with a white background or a colored background,
the bottommost image in the Layers palette is Background. An image can have one
and only one background.
Adding Layers
• Create a new layer by clicking on the Creates New Layer icon. A new layer will
be created above the active layer.
• Create a copy of a layer by dragging it to the Create New Layer icon. A
duplicate layer will be created above the original layer.
• Create a copy of the active layer by clicking on the Create New Layer icon. A
blank layer will be created above the active layer.
How to view/hide layers
Using Photoshop we can hide all the other layers of the image when we are working
on a particular part of the image. Just click on the eye near to the thumbnail of the
layer to hide a layer.