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PIXELSPIXEL = PICTURE ELEMENTIt’s the smallest unit of picture that can be controlled.

The number of distinct colors that can be represented by a pixel depends on the number of bits per pixel (bpp). A 1 bpp image uses 1-bit for each pixel, so each pixel can be either on or off. Each additional bit doubles the number of colors available, so a 2 bpp image can have 4 colors, and a 3 bpp image can have 8 colors:

1 bpp, 21 = 2 colors (monochrome)

2 bpp, 22 = 4 colors

3 bpp, 23 = 8 colors

...8 bpp, 28 = 256 colors

16 bpp, 216 = 65,536 colors ("Highcolor" )

24 bpp, 224 ≈ 16.8 million colors ("Tricolor")

MEGAPIXELA megapixel (MP or Mpx) is one million pixels,

and is a term used not only for the number of pixels in an image, but also to express the number of image sensor elements of digital cameras or the number of display elements of digital displays. For example, a camera with an array of 2048×1536 sensor elements is commonly said to have "3.1 megapixels" (2048 × 1536 = 3,145,728).

Print size (cm) Megapixels On-screen size

5.3 x 4 0,3 640 x 480

10.8 x 8 1,2 1280 x 960

13.4 x 10 2,0 1600 x 1200

17.2 x 13 3,0 2048 x 1536

25.4 x 16.5 5,3 3008 x 1960

26 x 17.2 6,3 3088 x 2056

34.2 x 23 11,1 4064 x 2704

BITMAP AND VECTOR IMAGES

BITMAP IMAGES (ALSO RASTER IMAGES) COMBINE DIFFERENT-COLORED PIXELS TO MAKE THE IMAGE. THESE IMAGES ARE RESOLUTION-DEPENDENT. IMAGES SAVED FOR ON-SCREEN DISPLAY HAVE A RESOLUTION OF 72 PPI AND IMAGES FOR PRINT SHOULD HAVE 300 PPI.

VECTOR IMAGES ARE NOT CREATED PIXEL BY PIXEL. THEY USE MATHEMATICAL EQUATIONS TO CALCULATE A LINE’S SHAPE. THESE ARE NOT RESOLUTION-DEPENDENT. THEY ARE GREAT FOR ILLUSTRATIONS AND LOGOS THAT NEED TO BE SCALED TO DIFFERENT SIZES.

FILTERSAre used to clean up or retouch your images,

apply special art effects that give your image the appearance of a sketch or pastel painting, and apply distortions and lighting effects.

As with many PS features, though, you should take care NOT to OVERUSE filters, as too many filters can make an image look busy or unprofessional.

Each filter has a range of settings. You can preview these before you apply them.

LIQUIFY FILTERThe liquify filter is another interesting filter you

can apply to images. It causes the image to appear melted.

Using tje liquify filter, you can push, pull, rotate, reflect, pucker, or bloat any area of an image.

WATERMARKWhen showing others your work, it’s a good idea to

apply a watermark to your images so your intellectual property (the image you worked hard to create) is protected.

A watermark is a partly visible message that marks the image as belonging to you.

You can apply a watermark by placing the watermark in a layer above the image itself and reducing its opacity.

Opacity refers to a layer’s degree of transparency.

GRADIENT MAPSThe gradient map command maps the tonal range

of an image to the colors of a gradient fill.

Tonal range describes the image’s colors, with the lightest color (usually white) at one end and the darkest color (usually black) at the other end. Every color in between can be expressed in a shade of gray. This tonal range is known as grayscale range.

A gradient fill is a blend of two or more colors.

ADJUSTMENT LAYER

As you apply color to an image, you will usually want to preserve your original image.

One way is to save a copy of your original image (this is always a good idea)

An adjustment layer applies changes to your image without changing the image’s pixels permanently.

HUE & SATURATION

Hue identifies easily named colors such as red, orange, and pink and simply refers to the color’s specific place on the color wheel.

Saturation describes relative intensity or dullness of a color from the inside to the outside of the wheel.

For hue, values reflect the number of degrees of rotation around the wheel from the pixel’s original color.A positive value indicates clockwise rotation.A negative value indicates counterclockwise.Values can range from -180 to +180.In other words, when you change hue positively, blues become more purple, yellows more green and so on.As you decrease hue, the opposite happens.