Scanning 101 and Beyond Media & Instructional Technology Services Darryl Simcoe, Instructor Scanning: process of converting images to digital data files Display on computer monitor Reprint on paper or overhead transparency Expose on photographic film Scanning: process of converting images to digital data files Display on computer monitor Reprint on paper or overhead transparency Expose on photographic film

Class Goal Convey essential information for productive scanning. Convey essential information for productive scanning. Build on basics as time permits.

Where do I begin? Start with the best quality original print or transparency available! --- "Golden Rule" of computing applies: GIGO (garbage in, garbage out) --- "Golden Rule" of computing applies: GIGO (garbage in, garbage out)

I have my original, now what? Choose the right scanner! --- Optimized for either reflective art or transparencies transparencies -- Resolution varies (number of pixels per inch -- Resolution varies (number of pixels per inch they can differentiate) they can differentiate) -- Ability to differentiate gradations in -- Ability to differentiate gradations in shadow areas varies shadow areas varies Choose the right scanner! --- Optimized for either reflective art or transparencies transparencies -- Resolution varies (number of pixels per inch -- Resolution varies (number of pixels per inch they can differentiate) they can differentiate) -- Ability to differentiate gradations in -- Ability to differentiate gradations in shadow areas varies shadow areas varies --- Given a choice, use a transparency scanner for 35mm slides or film negatives; scanner for 35mm slides or film negatives; use a flatbed scanner for reflective artwork use a flatbed scanner for reflective artwork --- Given a choice, use a transparency scanner for 35mm slides or film negatives; scanner for 35mm slides or film negatives; use a flatbed scanner for reflective artwork use a flatbed scanner for reflective artwork

Where can I find a scanner? Flatbed scanners: ITS Computing Lab - O'Connor Campus Center ITS Computing Lab - O'Connor Campus Center Media & Instructional Technology Services - Media & Instructional Technology Services - McGregory SB-8 (two available) Keck Humanities Resource Center - Lawrence Hall Keck Humanities Resource Center - Lawrence Hall Flatbed scanners: ITS Computing Lab - O'Connor Campus Center ITS Computing Lab - O'Connor Campus Center Media & Instructional Technology Services - Media & Instructional Technology Services - McGregory SB-8 (two available) Keck Humanities Resource Center - Lawrence Hall Keck Humanities Resource Center - Lawrence Hall Slide/transparency scanner: Media & Instructional Technology Services - Media & Instructional Technology Services - McGregory SB-8 McGregory SB-8 Slide/transparency scanner: Media & Instructional Technology Services - Media & Instructional Technology Services - McGregory SB-8 McGregory SB-8

Terminology Basic Terminology (see handout) Bitmapvs.Vector (object-oriented) graphics Bitmap vs. Vector (object-oriented) graphics Halftonevs.Contoneimages Halftone vs. Contone images Resolution & Image size Image Tone Image Tone Bit depth Bit depth

Bitmapvs.Vector (object-oriented) graphics Bitmap vs. Vector (object-oriented) graphics A bitmap image consists of pixels, whose color and location on a grid determine the appearance of the image. When editing bitmapped images, we edit individual pixels. A vector graphic is defined by mathematical objects called vectors, which determines the geometric characteristics of the graphic. When working with vector graphics, we edit shapes and objects rather than groups of pixels. Bitmap images are good at reproducing the subtle shading found in continuous-tone images, such as photographs. However, they are resolution dependent and thus can show jagged edges when magnified or printed at a higher resolution then they were created for. 3:1 zoom24:1 zoom Vector graphics display or print at the resolution available on output device (printer, monitor, film recorder). As a result, vector graphics enlarge well and are good at reproducing crisp outlines and details. 3:1 zoom24:1 zoom

Example of halftone grid representing grayscale image. White Light gray spot Dark gray spot Black (all dots off) (18.8%) (75%) (all dots on) Halftonevs. Halftone vs. Contoneimages Contone images

Example of a contone image: Continuous-tone (contone) image: the color or gray shade of each pixel can be varied (each has its own specific color definition made by building up varying densities of primary colors in the same spot) Halftonevs.Contoneimages Halftone vs. Contone images

Bit Depth Bit Depth Bit Depth: the particular number of bits (zeros and/or ones) making up each pixel in a bitmapped image; bit depth dictates the range of possible values for each pixel, and hence the total number of colors (or shades gray) that the image can contain.

Example of various bit depths:

Resolution is the measure of detail in an image, usually given in dots per inch (dpi) or pixels per inch (ppi). Resolution & Image size Image size is conferred upon a bitmapped image. With size comes resolution. An image's resolution changes as the image's (physical) size is altered. When making the image larger the pixels are simply displayed larger; when making an image smaller, the pixels are crammed into a smaller amount of space and each pixel is smaller.

Image pixel dimensions: 640 x 480 pixels Print size: 288 ppi (2.22" x 1.67") 13" Monitor: 640 x 480 setting 15" Monitor: 640 x 480 setting15" Monitor: 832 x 624 setting 21" Monitor: 1024 x 768 setting21" Monitor: 640 x 480 setting Regardless of specified print size, on-screen image size is determined by the pixel dimensions of the image, the monitor size, and the monitor resolution setting. Physical Size of Images on a Monitor

Image tone is the brightness, range, and balance of reds, greens, and blues in an image; tone varies depending on color balance, contrast between highlights and shadows, and dimness or brightness of midtones (gamma variations) Tonal manipulation is the key to setting the right contrast for images. Image Tone

Things to know before you scan ! What is the intended use? What size (dimensions) do you want the image to be when delivered? What size (dimensions) do you want the image to be when delivered? What image type are you scanning? What file format should the image be saved as? Knowing the following will help you set up your software for best results: Knowing the following will help you set up your software for best results:

Intended use... What "imaging" process will be used to What "imaging" process will be used to print, expose, or display the image? print, expose, or display the image? To be printed, exposed, or displayed?To be printed, exposed, or displayed? Continuous tone or halftone process? Continuous tone or halftone process? (see handout) (see handout) Resolution of printer, film recorder or monitor? Resolution of printer, film recorder or monitor? Type of paper if printing? Type of paper if printing? What "imaging" process will be used to What "imaging" process will be used to print, expose, or display the image? print, expose, or display the image? To be printed, exposed, or displayed?To be printed, exposed, or displayed? Continuous tone or halftone process? Continuous tone or halftone process? (see handout) (see handout) Resolution of printer, film recorder or monitor? Resolution of printer, film recorder or monitor? Type of paper if printing? Type of paper if printing?

Intended use... Printing black-and-white line art Limit scan resolution to maximum resolution of the printing device Experiment with lower settings Best compromise betweem file size and quality High resolution imagesetters: use 800 ppi minimum, preferably ppi Exception: 400 to 600 ppi usually adequate if printing to newsprint or other porous paper Printing black-and-white line art Limit scan resolution to maximum resolution of the printing device Experiment with lower settings Best compromise betweem file size and quality High resolution imagesetters: use 800 ppi minimum, preferably ppi Exception: 400 to 600 ppi usually adequate if printing to newsprint or other porous paper

Intended use... Printing grayscale & color bitmapped images on halftone devices (e.g., laser printer or imagesetter) Limit scan to 2 times the printer's default screen frequency Often 1.5 times the screen frequency or less will give adequate results (especially on porous, uncoated paper or newsprint) Printing grayscale & color bitmapped images on halftone devices (e.g., laser printer or imagesetter) Limit scan to 2 times the printer's default screen frequency Often 1.5 times the screen frequency or less will give adequate results (especially on porous, uncoated paper or newsprint)

Intended use... Displaying on a computer monitor Limit image resolution to what the screen can display Default screen resolution is usually 72 ppi on Mac monitors and 96 ppi on PC monitors Rule of thumb: Use 75 ppi Displaying on a computer monitor Limit image resolution to what the screen can display Default screen resolution is usually 72 ppi on Mac monitors and 96 ppi on PC monitors Rule of thumb: Use 75 ppi

Intended use... Exposing or printing to continuous-tone output devices (e.g., film recorders or dye- sublimation printers) Ideally, match scan resolution to output device resolution Practically, doing so may result in an unrealistically large file to work with Seek an adequate compromise between resolution and file size. (i.e., experiment!) Exposing or printing to continuous-tone output devices (e.g., film recorders or dye- sublimation printers) Ideally, match scan resolution to output device resolution Practically, doing so may result in an unrealistically large file to work with Seek an adequate compromise between resolution and file size. (i.e., experiment!)

Intended use... Polaroid digital film recorder Import image into Powerpoint for exposing to film Match the image dimensions to the PowerPoint slide dimensions Format slide background to black Polaroid digital film recorder Import image into Powerpoint for exposing to film Match the image dimensions to the PowerPoint slide dimensions Format slide background to black

What physical size (dimensions)? Remember, image size is conferred Remember, image size is conferred upon a bitmapped image. They have upon a bitmapped image. They have no physical size (just a set number of no physical size (just a set number of pixels) until you specify the height and pixels) until you specify the height and width. width. Determine the desired output size and Determine the desired output size and specify it in the software settings. specify it in the software settings.

What image type is being scanned... Select software setting appropriately Select software setting appropriately for the type of image desired for the type of image desired Often the same as the original, but Often the same as the original, but there are some exceptions there are some exceptions

What file format to save in? Know which file formats can be imported into the software program you'll use to print the final image. Know which file formats can be imported into the software program you'll use to print the final image.

What makes a good scan... (and why you should care…) Image tone Image tone Color balance Color balance Resolution Resolution

Examples of software setup: Apple Color Onescanner via Adobe Photoshop

Examples of software setup: Sprintscan 35 (slide/transparency scanner)

Some tips... Tip: Don't use "brightness" or "contrast" controls on images… too much data is lost. Use on channels or masks only. Instead, use levels or curves on images… less data loss.

Some tips... Tip: Don't upsample unless using as a method of doubling your scanner's line art resolution. Interpolation adds data, but not detail (information), resulting in soft or blurry images.

Some tips... Tip: Lose noise introduced by the scanner by scanning at the maximum optical resolution, then downsampling to the resolution you need. (Noise tends to show up as single pixels. Downsampling creates new pixels by averaging surrounding pixels, so noise is reduced significantly.)

Some tips... Tip: Scan b&w line art in grayscale mode then use various techniques (sharpening, thresholding) to massage the image. Finally, convert the image mode back to b&w.

Some tips... Tip: When rescreening a screen (scanning a halftone image), scan at high resolution, downsample using Bicubic Interpolation, print at smaller size than original.