Digital Photo Correction & Manipulation Tonya Hines, CMI Certified Medical Illustrator Art Director, Mayfield Clinic

Today you will learn  Resolution What is dpi? How much resolution for specific uses  File formats jpg, gif, tif, pdf, psd Which file format to use and why  How to correct and manipulate Color photos Newspaper clippings Diagnostic scans (MRI, CT, angio)

If you only learn 1 thing!  Relationship of resolution and image size

garbage in = garbage out Digital imaging Image capture: steps taken to digitize an image Image correction: steps taken to correct hardware interference with color and resolution Image manipulation: steps taken to artistically change an image for a desired effect

Before you acquire images  What is the final use of the image? On-screen/web (PowerPoint, MySpace, , wallpaper, digital photo frame) Laser or inkjet prints (scrapbooks, handouts) Photo printing or publication  Answer tells us Resolution and file size needed Best method to capture it shopping without knowing shirt size

72 dpi 150 dpi What is resolution? Number of pixels per inch (blocks of color or gray that make a picture) More pixels per inch = higher res = more detail But also = bigger file size! pixel per inch (ppi)= dot per inch (dpi)

Resolution & image size are directly proportional = 20 Mb file 8” x 10” 300dpi 41.6” x 33.3” 72dpi 2400 pixels 3000 pixels

Resolution & image size are directly proportional 20 Mb file > 1.2 Mb file 8” x 10” 300dpi 8” x 10” 72dpi 2400 pixels 3000 pixels 576 pixels 720 pixels

Why would I ever want small file size?  Reduce system resources and time in processing and printing  Too large to as an attachment  Fill up recipients boxes (over quota)  Maximize storage  More resolution beyond your purpose is waste bigger is not always better Resolution is Height x width Dots per inch File size

Resolution by usage/output Output or printerDPI needed Web72 Computer monitor96 Black and white laser printer150 Color inkjet printer Photo inkjet printer Newspaper Offset printing (brochures, books) don’t confuse image res with printer res

Common resolutions Usagedpifile size PowerPoint 10” x 7.5” MB Laser / inkjet prints 8” x 10” MB Photo prints 4” x 6” MB 5” x 7” MB 8” x 10” MB

But I don’t know today all the possible uses of my image… 300 magic number 5 x 300 dpi

Problem with publication PowerPoint or web image 10” x 96 dpi 1.98 MB Publication image 6” x 300 dpi 6.18 MB can’t publish with web images

When resolution is too low  Scaling - doesn't change the number of pixels, just the resolution Height x width Dots per inch File size 4 x dpi 6.18 MB 8 x dpi 6.18 MB

When resolution is too low  Resampling - changes the number of pixels Downsample - delete pixels; cut file size Upsample - add pixels; increases file size upsampling doesn’t add detail = fuzzy 4 x dpi 6.18 MB 4 x dpi 3 MB 4 x dpi 6.18 MB 8 x dpi 20 MB very common interpolation

If you only learn 1 thing!  Relationship of resolution and image size BREAK?

Capture devices Cell phone camera Point-n-shoot camera SLR digital camera Flatbed scanner Digital video camera

Garbage in = garbage out Cell phone Point-n-shootSLR

Image editing software Beginner Google Picasa free Adobe Photoshop Album free Mid-level - home / business use Adobe PhotoShop Elements$100 Corel Paint Shop Pro $100 Advanced - graphics professional Adobe PhotoShop CS3 $650 don’t buy CS3 - invest in a better camera

Demos  Portrait photos Remove red eye / flash reflections in glasses Too dark - too light Remove date stamp  Landscape photos Straighten horizon line Remove telephone lines  Group photos  Diagnostic scans  Newspaper clippings

Image correction steps 1. Crop 2. Resize # of pixels 3. Adjust highlights and shadows (levels) 4. Adjust color balance 5. Sharpen filters 6. Save as appropriate file format (master) 7. Remove blemishes 8. Convert to grayscale or CMYK if appropriate 9. Save as appropriate file format (output version)

Crop & resize # of pixels  Crop tool No restriction Aspect ratio > select size (5 x 7 in)  Image > Resize > Image size dialog box Resampling changes # of pixels

Black point White point Tonal correction  Histogram based on 256 levels of gray Black point (0) White point (255) Mid-range slider  Enhance > Adjust lighting > Levels

Color correction  Color correct by adding or removing color complements

About color management  RGB  sRGB  CMYK

Over sharpen = halo artifacts and aliasing Sharpening  Filter > sharpen > unsharp mask Amount = ~ 100% Radius = 1.5 Threshold = 4

Remove blemishes  Eraser  Clone  Healing brush  Red eye removal corrected

Save - File formats Applications.jpg.gif.png.pdf.tif.psd PowerPoint XXXXX XXXX Website XXX InDesign XXX PhotoShop XXXXXX Word XXXXX Use compression

File formats .jpg (joint photographic experts group) Compression options 1-12 Good for PowerPoint, web, and Caution: repeated saves degrades image quality .tif (tagged-image file format) Most popular, good for transfer Mac to PC Preferred format for publication Retains layers .psd (PhotoShop document) Retains layers Can only be opened by Photoshop

Save as  Select TIF from format menu  Name the file  Select location to “save as”  Click save  For JPEG  Select 7 (medium)

Photo printing  Online printing & sharing Kodak Gallery Snapfish Flickr  Print only services Photo kiosks at CVS, Walgreens, Kroger, Biggs

Image catalog/databases  Organization Subcollections Metadata File naming  Database software  Storage (with backup!)  Long-term expandability

Catalog & storage  Software (image preview, search functions) Picasa iPhoto ACDSee Photo Manager Extensis Portfolio  Storage (with backup!) CD or DVD Hard drive External hard drive Online