Photoshop: Getting Started
The Photoshop is a software tool developed by Adobe, for enhancing picture qualities and adding effects to them. It comes with a host of bundled features to give you stunning results.
Photoshop is used for rafter images. In computer jargon, there are two types of images, rafter and vector images. While the vector images are formed by predefined lines and curves, the rafter images are formed by a grid of tiny squares, called pixels.
All bitmap images are nothing but a collection of colored squares (pixels) spread across the screen,. When magnified these look like nothing but original squares, it is only when they are blended together that they take the form of an image. Quality of an image is based on the number of pixels per inch. It is called as ppi. Higher the ppi sharper is the image quality.
Another important fundamental of images is pixel depth. This is the measurement of the number of bits of stored information per pixel. That is the amount of color information that can be loaded per pixel. It is referred in terms of powers of two. For e.g. a bit depth of 8 shall refers to 2**8, or 256 possible values (colors).
Image resolution/size refers to physical dimension of an image; image resolution is the number of pixels per linear inch. An image with 72 ppi (pixels per inch) – gets you 5,184 pixels per square inch.
Opening or saving images for the purpose of Photoshop is something not very different. All you have to do for opening existing images in CD-ROM or hard disk is to use File->Open.
Creating new images is not difficult either just choose File->New to bring up New dialog box and in case Clipboard contains an image, the Width, Height and Resolution option boxes shall automatically show the size and resolution of that image.
To scan new images, the acquire command can be used from the fikle menu. Determining the scan resolution shall depend on the capability of your output device. If the image is used on screen, the best is 96 ppi for PC compatibles, or 72 to 120 pixels per inch for a Macintosh monitor.
Scan resolution determines the size of the scanned file. For example, the size of an image with a resolution of 200 ppi shall be four times greater than an image of identical dimensions and a resolution of 100 ppi.
Screen frequency is the screen resolution that you will use when printing your final image.
As a general rule, always keep the image resolution as twice the screen frequency to achieve the best printed results.
The software itself comes with a plethora of tools. For e.g., the marquee tool shall allow you to select rectangular or elliptical areas by dragging over an area of the image. By default, the marquee is dragged from its corner. Another handy tool is the “lasso” tool. It allows you to make a selection by dragging a freehand outline around an area. You can also constrain all or part of the outline to straight-edged segments.
Then there are others like the airbrush and the paintbrush that allow you to give color effects. Ranging from gentle brush strokes to traditional airbrush techniques, it allows you to perform a host of styling effects.