File Formats

what is the standard resolution for web?

72 ppi

Smallest file size for photos on the web?

JPEG

Worst choice for logos/graphics/line art?

JPG smears text, lines, and edges, and adds artifacts

JPEG

Joint Photographic Experts Group Designed for compression full color or greyscale images. Preferred to the GIF for photos. Pros: (a) good for photos (b)good for photos with LOTS of color info/tonal qualities Cons: (a) LOSSY-- some info is lost during compression (b) Every time you resave it some info is lost

TIFF

Tag Image File Format Pros: (a) format of choice for archiving photos (b) for high quality images (c) good for high resolution stock photos (d) used in commercial printing environments Cons: (a) VERY LARGE

what is the standard resolution for print?

300 ppi

CMYK

-"Cyan-Magenta-Yellow-Black" -USED FOR PRINT -SUBTRACTIVE (meaning the higher the tonal value, the lighter it gets) -0 is the ABSENCE of color (white) while 255 is BLACK

Greyscale

-"black and white" -additive -used for screen output and print -black (0) to white (255), 256 shades total

RGB

-"red-green-blue" -used primarily for screen output -similar to greyscale in that each color "channel" contains tones from black (0) to white (255) and a gradient of shades in between, except gray shade translates to the tonal strength of the particular colour

Vector-Based Graphics

-composed of PATHS (lines curves and shapes that are MATHEMATICALLY DEFINED) -resolution INDEPENDENT -SCALABLE (visual clarity not lost with resizing) -illustrator, freehand, flash, coreldraw -.al,.cdr,.swf,.svg

Raster (Bitmap) Graphics

-composed of pixels -resolution dependent -resizing REDUCES QUALITY -best used for photos -photoshop, scanned images, and images from camera -.jpg, .png, .tiff, .bmp (only .gif and .png support transparency)

What formats must a file be saved in to be visible on the web?

GIF TIF JPEG or PNG

Worst choice for photos?

GIF because it only supports 256 colors and is a really large file

Best choice for logos/graphics/line art on the web?

GIF or PNG

GIF

Graphic Interchange Format. Best for line art, logos, and illustrations. Benefits: (a)LOSSLESS; image is just compressed. (b)BEST USED FOR IMAGES WITH LIMITED COLOR (c)no blurry edges (good for vector images) (d) supports transparency (e)supports animations Cons: (a)Limited palette of 256 colors (b) not good for PHOTOS or STORAGE

Which format is better, GIF or PNG and why?

PNG is better because it has 24-bit color support, compression, anti-aliasing capabilities. The only disadvantage is that it is not supported by some browsers.

PNG

Portable Network Graphics Pros: (a) lossless (b)supports MILLIONS of colors (c)supports transparency (d)no jagged edges (e)good for vector images Cons: (a) not supported by some browsers (b)slow downloading speed

Best formats for logos/graphics/line art for print?

TIF or PNG (lossless compression and no JPG artifacts)

What are the two best formats for photographic images for print and why?

TIF or PNG because they are lossless and there are no JPG artifacts

what are the two ways of measuring image resolution?

ppi- pixels per inch (refers to pixels) dpi- dots per inch (refers to PRINTER ONLY)