ES 101. Module 14 Other Graphics File Formats

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ES 101. Module 14 Other Graphics File Formats
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Last Lecture(s)

• Color Pallettes
• Graphics Interchange Format - GIF
• Joint Photographic Experts Group JPEG
• Tagged Image File Format TIFF

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This Lecture

• More Graphical Image Formats
• Bitmapped Images BMP
• Portable Network Graphics PNG
• Windows Icon ICO
• Photo CD PCD
• Paintbrush PCX
• and other miscellaneous formats
• Graphics viewers
• Web browsers
• OLE applications
• Windows accessories

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This Lecture (contd)

• Graphics editors
• Paint Shop Pro vs. Adobe Photoshop
• Image Capture
• Scanning

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Bit Mapped Image - BMP

• BMP is the native Microsoft Windows format
• It can be used for wallpapers, backgrounds, and
  other graphics
• BMP files describe an image at the bit, or pixel,
  level and are generally not compressed
• As a result, BMP files tend to be large
• This makes them unsuitable for web pages

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Why arent BMP Images Compressed?

• They werent designed for transmission via a
  network
• They were designed to be used by the OS to
  refresh a video display
• Transmission time was not a consideration
• In general the back plane of the PC and the video
  graphics circuitry provide very high performance

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BMP Internals

• As in all other graphics formats, a BMP file
  contains a header which describes the file,
  containing
• Dimensions in pixels
• Color depth
• Compression type
• Number of colors actually used in the bit map
• Number of colors considered important in the bit
  map
• The last sub-bullet deals with the problem of
  using a monitor that cant display the full color
  palette
• The video card knows which colors can be thrown
  away
• This is different for each image

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BMP Color Depth

• BMPs can have 1, 4, 8, or 24 bit color depth
• For every level except the 24-bit, the
  information header defines the color palette
• The main file consists of a string of indexes to
  the palette
• For 24-bit color depth, no palette is required
• Full color information is provided for each pixel

So, for a 1024 X 768 BMP, and 24-bit depth,
how big would the image file be?
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18.9 Megabits!
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BMP Compression

• Only 4 and 8 bit images can be compressed
• BMP uses a lossless compression technique called
  Run Length Encoding (RLE), which is quite
  different from GIF and JPEG
• It replaces strings of identical bytes with a
  token indicating how many bytes of what color
  were replaced
• This is a lossless technique
• To decompress the data, you expand the tokens

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Device Independent Bit Maps - DIB

• Sometimes BMPs are referred to as a Device
  Independent Bitmap
• All BMPs are device independent, since they are
  stored in such a way that they can be displayed
  on any monitor

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Creating BMPs

• MS Paint can create simple BMPs
• Most other graphics editors can as well, but MS
  Paint is included with your OS

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Other BMP Information

• There are many sources of BMPs on the web, since
  they are most times used for wallpapers
• Google BMP and cruise around
• You can also find a lot of specs and more
  detailed descriptions on the web

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Portable Network Graphics - PNG

• As mentioned previously, the PNG format is now
  appearing on the web
• Replacing GIF due to legal problems with the
  compression algorithm licensing
• PNG is pronounced ping
• It offers much greater color depth, and an
  improved grayscale
• 48 bit color depth
• Slightly better data compression than GIF,
  although not as good as JPEG
• Better interlacing and transparency

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Windows Icon - ICO

• If you want to fool around with the icons and
  title bars of your desktop, you can develop your
  own icons
• An icon is a 4-bit, 32 X 32 pixel image stored in
  ICO format
• ICOs can have a transparent color that adapts to
  the color selected for your screen
• To create ICOs, you have to have an icon editor

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Photo CD - PCD

• If you go to a film processor, you have the
  option of receiving a CD of your photos
• These are not JPEGs, but PCDs
• The PCD format was invented by Kodak, and yields
  the highest possible image quality
• Much higher than ordinary desktop scanners
• PCDs are scanned directly from film
• One CD-ROM can hold about 100 photographs
• You normally dont need this quality for a web
  site
• The image would take forever to load

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PCD Internals

• When a photo is scanned, each image is digitized
  at six resolution levels
• 128 X 192 pixels, up to
• 4096 X 6144 pixels
• The highest resolution image contains so much
  detail that it is nearly indistinguishable from
  the original photo
• Each PCD file contains the entire range of
  resolution levels for a single picture
• Most fully featured graphics viewers and editors
  can handle the PCD format, but it can go slowly
• Paint Shop Pro

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Other File Formats
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Compression and Encoding

• Sometimes you download an image file from email
  or the Internet, and it has been either encoded
  and/or compressed for transmission
• It this case, you must decode/expand the file
  before you can access the image file itself
• Most times the file has been zipped and must
  therefore be unzipped
• Be aware that these compression techniques
  achieve very little reduction in file size if you
  have already used a compression technique

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Unknown File Format

• What do you do if you receive a graphic from a
  source, but do not know the file format
• First, look at the file extension
• Example .pps is the format for Paint Shop Pro
• Open the file with a text editor like Notepad
• It will look like gibberish
• However, the beginning of the file may have some
  revealing information
• GIF Files contain GIF89a
• JFIF Files contain JFIF
• BMP Files contain BM

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Graphics Viewers

• Web browsers
• All will open GIFs and JPEGs
• You can open local files on your hard drive
• Office applications
• Object Linking and Embedding (OLE) compatible
• OLE is a feature of many MS Windows applications
  that allow insertion of foreign files
• This is done by the Inserf Object command
• Windows accessories
• Paint BMP and PCX files
• WordPad OLE client

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Graphics Editors

• Graphics editors allow you to view, crop, resize,
  convert, and add text and other effects to an
  image
• There are two workhorse applications that are
  widely used
• JASC Paint Shop Pro - 105
• Adobe PhotoShop - 650
• As can be seen, PSP is the least expensive
• However, you get a very sophisticated editor for
  the money
• So, lets take a look at Paint Shop Pro

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What can PPS do?

• Create new graphics from scratch
• View and edit existing graphics formats
• Retouch photos
• Capture graphics from your computer screen
• Screen scrape
• Useful for importing graphics from Adobe pdf
  documents into MS Office applications
• Convert between graphical file formats
• Create animated GIFs, using JASC Animation Pro
• All for only 105!!

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Basic PPS Editing Tools

• Resizing
• Cropping
• Flipping
• Rotating
• Adjusting colors
• Increasing and decreasing color depth

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Web Sites

• By now, you should have created your web site,
  and gotten it hosted on the webdev server
• The requirements are as previously stated
• Frames page with 3 frames
• 10 subpages
• Content of your choice
• However, you must be willing to publish this work
  on the web
• No improper content
• Those of you who are working on existing web
  sites must rehost your web on the server in order
  to receive a grade
• These web sites will be archived in the VSC-IT
  library at the end of the semester as examples of
  your work

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Web Sites (contd)

• If you dont rehost your existing web site, or
  fail to create a web site on the webdev server,
  I will not be able to give you a grade, since
  this is the only work that you will do this
  semester
• You will receive a grade of incomplete or I
• At the point in time that you meet the
  requirements of the class, I will fill out a
  grade card to change your grade
• It is my intention to have a design jury for
  these web sites and rank the web sites
  accordingly
• Best in Show
• Most creative theme
• etc.

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Next Lecture(s)

• Paint Shop Pro
• Animated GIFs
• Semester wrapup