Working with Image Areas (Lesson 1)

Working with Image Areas

Introduction

Now you are familiar with exploring the Photoshop environment and the components in it. You would like to create a drawing and work on it. In this lesson, you will select image areas using the various selection tools in Photoshop.

While working with an image, you might need to work on its specific areas. Your selection may be different according to your requirement. However, you can easily make the most complex selections using the built-in tools in Photoshop.

Image Resolution

Image resolution is the sharpness and clarity of an image. It is the number of pixels in the horizontal or vertical direction and is measured in pixels per inch (ppi). The greater the ppi of an image, the higher is its resolution and quality.

Image resolution is used to determine the image data value along with its pixel dimension.

Color Mode

Color mode is defined as the mode that is used for displaying and printing images. It determines the number of colors, channels, and the image file size. The color mode is based on the color models used by images during publishing.

Example:

Different Color Modes in Photoshop

Photoshop images can be classified into different color modes based on the color information they contain. Some of these modes are specific to black and white images.

The table below describes the various color modes in Photoshop

Color Mode	Description
RGB Color	It uses three channels to represent color. Each color component is red, green, or blue can use 256 shades. The RGB color mode is most commonly used for images distributed electronically. It is also used by monitors and scanners.
CMYK Color	It uses four channels to represent color. The color component is Cyan, Magenta, Yellow, and Black. The four channels result in over 4 billion available colors. This mode is used by printers.
Multichannel	It contains 256 levels of gray in each channel. It is used for specialized printing. Multichannel mode support many file formats.
Bitmap	It uses a single channel that results in two shades of brightness that is black and white. This mode does not contain any intermediary gray levels. This mode is used for creating simple logos, line art, and special effect such as mezzotints.
Grayscale	It uses single 8-bit channels. This results in 256 brightness level ranging from 0 (for pure black) to 255 (for pure white)
Duotone	It uses a single 8-bit channel. This mode allows you to use two to four inks to print certain tones of the image in different colors. It is typically used to print tinted images with special ink requirements.
Indexed Color	It uses a single channel to represent color. The bit depth can be set from 1 to 8 bits. A color table is used to determine the available colors.
Lab Color	It uses three channels to represent color. This color mode defines colors mathematically and is not device specific. The color component are L- luminance component ranging from black to white, A – chromatic component ranging from green to red, B – chromatic component ranging from blue to yellow.

Navigation Tools in Photoshop

One may find it necessary to have a closer look at an image to select or edit a part of it. Using Photoshop, you can save time zooming out or switching between documents without scrolling palettes. Photoshop offers tools, commands, keyboard shortcuts, and floating palette to view images easily. 

The Zoom Tool

The zoom tool allows you to vary the magnification of an image. The Zoom In tool is used to increase the magnification of the image, the Zoom Out tool also decreases the magnification of an image. You can zoom to a maximum over 3200 percent by using the tool. Moreover you can further improve the good quality of the zooming process by using the zoom tool options bar. The keyboard shortcut key of Zoom tool is (Z). While using the Zoom In tool, you can also hold on the Alt key to Zoom Out the entire image.

The Navigator Palette

Now let’s move onto the navigator palette further more. The Navigator palette allows you to find the right way to deal with complicated situation through a document by providing a number of options. The view box in this palette shows a very small detailed view of the entire image. This palette also provides a Zoom Slider that can be used to quickly choose a magnification level without selecting the Zoom tool while using different tool. You can even specify a particular magnification value using the magnification text box is red in a square shape; you can drag it to select a specific portion of entire image by dragging the magnification text box.

The very small detailed view of the document as displayed in the Navigator palette.

The New Dialog Box

The New dialog box contains options that allow you to set the Width and the Height of an image. It allows you to choose the Resolution and Color Mode for the image. You can also choose values from the Preset drop down list to automatically specify the dimensions and settings for the image. You can set the background contents to be White, Background Color or Transparent.

The settings of the Flower of the Day Film Banner file as displayed in the New dialog box

  

File Information Box

Once you create a new document, the status bar of the document window displays the file information box. The file information box allows you to view and check document sizes. In this box, the data on the left side represents the size of the document with one layer information. The data on the right side shows the size of the image as Photoshop saves it, with all the extra layers and channels affecting file size. 

Info Palette

The Info palette provides document status information. It also displays information related to the current selected tool. The color values for the current mode appear on the left side of the Info palette, and CMYK values appear to the right.

 

The very small detailed view of the Info palette.