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Unformatted text preview: Edited by Foxit Reader Copyright(C) by Foxit Software Company,2005-2007 For Evaluation Only. GRAPHIC FILE FORMATS
VECTOR IMAGES VS BITMAP IMAGES Vector Element A mathematical outline which uses curves to create a shape points and beziers Resolution independant , can be scaled up or down without compromising quality Fonts, Illustrator Files, and PhotoShop close crop Paths are all examples of vector data Bitmap Element Images are broken into pixels . These pixels can be 1 bit data (line), 8 bit (B&W haltone), 24 bit (RGB colour) or 32 bit (CMKY colour) Resolution dependent, cannot be without compromising quality scaled up or down Scanned images are examples of bitmap elements
Page 1 of 7 CGRA 013 - INTRODUCTION TO ELECTRONIC PREPRESS Edited by Foxit Reader Copyright(C) by Foxit Software Company,2005-2007 For Evaluation Only. Graphic formats for continuous tone images (i.e. scans) are always bitmap, however they can hold vector data (such as a PhotoShop EPS file with a clipping path ). Conversely, Vector formats can have a combination of vector and bitmap data (such as an Illustrator file with a PhotoShop EPS scan placed in it). Page Assembly programs, such as Quark XPress, specialize in combining both formats in a WYSIWYG environment. Vector File Formats EPSF - Encapsulated PostScript File ( Adobe Illustrator ) Adobe Type I, II, III PrinterFonts TrueType Fonts Bitmap (Scanned Image) File Formats TIFF - Tagged Image File Format 24 (RGB) & 32 (CMYK) bit are opaque 1 bit (LINE), 8 bit (GREY SCALE) are transparent Saved as MAC or PC -the difference is the low res preview that is created for placement in Quark ( Pict for Mac, Tiff for PC ) Saved as "PC" should have no compatibility issue EPS - Encapsulated PostScript - Composite - regular EPS file EPS ( DCS expansion ) - separates CMYK data into separate files linked to a low res preview which is embedded in the QUARK DOCUMENT Can be problematic when output in a composite workflow ie. Apogee 1, 8, 24, 32 bit ALL opaque
CGRA 013 - INTRODUCTION TO ELECTRONIC PREPRESS Page 2 of 7 Edited by Foxit Reader Copyright(C) by Foxit Software Company,2005-2007 For Evaluation Only. Bitmap (Scanned Image) File Formats - Con't Scitex CT - Very similar to TIFF GIF - Graphic Interchange Format Indexed Colour ( 250 colors only - Internet use PICT - Macintosh low res picture format BMP - Windows low res picture format Compressed Formats - JPEG - CMYK or RGB Smaller file size due to compression JPEG compression is lossy - the greater the compression, the more data is lost (Max 3:1 industry recommendation) Compatibility issues - Postscript Level II or greater RIP required - LZW, ZIP, FLATE Lossless compression ) Compatibility issues ( PSI ) CGRA 013 - INTRODUCTION TO ELECTRONIC PREPRESS Page 3 of 7 ...
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