Digital Image Printing

Digital Image Printing 101 

• For each different type of output, a differnt processing is required to fit that output.
• Regardless of size or quality, there are two main printing branches. A continuous tone printing such as a photo finishing print and a digital halftoning print such as a magazine or book.
• What are some considerations?
  1. desired audience
  2. quality expectation
  3. cost
  4. output medium
  5. durability of output
  6. processing complexity

Scenerio 1 

• Here is my recommendation:
  1. You download the images to your computer.
  2. You go into Picasa application and browse through each image and perform some basic adjustments (brightness/contrast, rotate/cropping, sharpening) and export to a folder. By the way, you don't need more than 3 MegaPixels (2000x1500) for this output.
  3. Upload the JPG files to a photo finishing site such as Snapfish.
  Snapfish
  4. Order the prints and quantities (number of copies) and that is it. Your prints will arrive in the mail in about 3-5 days.
  5. This is the cheapest and best for these type of images. It cost 12 cents per print plus some shipping.
  However, if you are in a big hurry, you can always go to your local CVS or Wal-mart and get a print in about 1 hour (19 cents per print).

Scenerio 2 

Some background information... 

• RGB - Color in imaging is represented by RGB (red/green/blue) triplet to create all the various shades of color you see on your display. This is the additive color system where the 3 primary color components add and mix to create all the various shades of color - a possible 16 Million combinations in a 24 bit color system.
  
• CMYK - In printing, color is represented by the subtractive system of inks on paper. CMYK represents cyan, magenta, yellow and black. The key to quality color printing is mapping the RGB input to a CMYK output for printing. This conversion process is sometimes referred to as screening or halftoning.
  
  This is a zoom image of a rosette (detail of most prints).
• Screen angle -
• dot gain -
• dpi -
• color separation -
• halftoning -
• moire -

Some examples of prints... 

Here is a sample monochrome digital print from TIME magazine:

Here is a zoomed view through a 10x magnifier:
(Notice the dots arranged at 45 degrees screen angle)

Here is a color print from TIME magazine:

Here is a zoomed view thru a 10x magnifier:
(noticed the rosette pattern)

Here is an example of a traditional Kodak print:

Here is a 10x zoom view of the above image. Noticed the lack of dots. This is a continuous tone print.