The right resolution � Depends on � Image type � What is output device capable of? � There is no “universal” scan. � Too high saves immense amounts of data without improving image � Too low results in poor image quality
The right resolution - Print � Line copy � Use the full resolution of the output device � Printers range from 300 dpi to 1440 � Anything over 400 is hard to see the difference See Page 7
The right resolution - Print Color or Greyscale Printers simulate colors and shades of grey by “halftoning”
Halftoning � Color printers work this way also � Except with four layers of color
The right resolution - Print Color or Grey One and a half to two times the printer’s “halftone frequency” � 125 to 200 dots per inch See Page 9
The right resolution - Print � Be sure to specify final size of the image. � Resolution (dots per inch) changes if the number of inches changes. � i.e. if you resize in the final application
The right resolution - The screen � Monitors and projectors can display any color for each pixel � The size of monitors and projectors is commonly expressed in numbers of pixels rather than physical size � 640 x 480, 800 x 600, 1024 x 768
The right resolution - The screen � Treat line copy, “graphic” images, grey scale and color the same. � Use indexed color or grey scale instead of 1-bit for line copy images. 1-bitgreyscale
The right resolution - The screen � Powerpoint � Assume you will be using a 1024 x 768 projector. � Powerpoint thinks its slides are 10 x 7.5 inches � Acquiring 10 x 7.5 inches at 100 dpi gives you the right number of pixels � if your image is intended to fill the screen
The right resolution - The screen � The web � Web browsers ignore any information that refers to physical size. � Only dimensions in pixels are taken into account
The right resolution - The screen � The web � Different users may have different sized monitors at different resolution. � Assume a browser window 750 pixels wide. � It won’t always be right, but it’s the most common.
The right resolution - The screen � The web � You can resize images with HTML commands � But it’s a really bad idea.
Digital Camera resolution 6 Megapixels – 2832 x 2128 3 Megapixels – 2048 x 1536 1 Megapixel – 1280 x 960 VGA – 640 x 480
File formats - TIFF Supports any size, resolution or color depth. Best format for “desktop publishing” Modest file compression (LZW)
File formats - JPEG Use for “natural” pictures: photographs, drawings For print applications use highest quality For internet, medium quality is OK “Lossy” compression - don’t use if you’re going to manipulate image
File formats - GIF Use for “graphic” pictures: charts, diagrams Requires indexed color Only format that features transparency and interlace.
Embedded files When you place a file in PowerPoint… your file size increases by the size of the placed files.
Linked files When you place a file in Pagemaker… your file size increases only slightly but, you have keep the image file in the same place for Pagemaker to use when it needs to display or print the file Put everything in a folder If you move it, move the whole folder.
Optical Character Recognition � Requires scanner and OCR program � Results are pretty good but not perfect � Images and text saved as separate files � Make sure original is placed in scanner straight.