Images

Image Formats

Image Formats

Raster vs Vector

Raster - Image data stored as "pixels."

  • DPI - "dots per inch" is typically 300 for print, 72 for web (but doesn't matter).
  • Retina / "high DPI" - 2 pixels for every 1
  • Blurry when enlarged
  • Program of Choice: Adobe Photoshop
  • Best Formats: PNG & JPEG

Image Formats

Raster vs Vector

Vector - Draw shapes with math

  • Use math to draw shapes using points, lines and curves
  • Typically used for fonts and logos
  • Program of choice: Adobe Illustrator
  • Format of choice: SVG

Image Formats

Raster vs Vector

Image via tutorialspark.com 

JPG / JPEG

  • Raster
  • "Joint Photographic Experts Group"
  • Up to 10:1 compression
  • Best when many colors are present with smooth variations between the colors, like a photo or painting.

PNG

  • Raster
  • "Portable Network Graphics"
  • Different compression levels:
    • 8-bit (256 colors)
    • 24-bit RGB
    • 32-bit RGBA
  • A = Alpha (transparency)
  • Best for icons, logos, or when you need to use transparency (example)

webcomic via lbrandy.com

GIF

  • "Graphic Interchange Format"
  • 8-bit (256 colors)
  • Supports animation, but video formats (MPEG / WEBM) have better compression.

SVG

  • "Scaleable Vector Graphics"
  • Vector!
  • Create with Adobe Illustrator (preferred), Photoshop, or using HTML-style markup. Learn more here.
  • Complex animated example: slack.com (underlines and exclamation points)
  • Simple example (view online here): 
<svg height="210" width="400">
  <path d="M150 0 L75 200 L225 200 Z" />
</svg>

Additional Formats

  • TIFF - uncompressed (don't use)

  • BMP - BitMap - similar to JPG but less efficient

  • WEBP - Web Picture, great compression but not supported across all browsers (caniuse.com/webp)

Let's prepare an img

Adobe Photoshop --> preferred

pixlr.com/editor --> free online editor

Image Copyright

Everything is Copyrighted unless it tells you otherwise

Creative Commons

  • Copyright, but allows certain uses.
  • Three Variables:
    • Commercial / NonCommercial
    • Attribution
    • Derivatives (No Derivatives / Share Alike)
  • More info: creativecommons.org/licenses/

Resources page 1

Flickr advanced search

thenounproject.com

 

freevectorfinder.com

iconfinder.com

https://stocksnap.io/

http://www.gratisography.com/

http://www.splitshire.com/

http://littlevisuals.co/

http://www.lifeofpix.com/

http://images.superfamous.com/

https://picjumbo.com/

http://www.nypl.org/research/collections/digital-collections/public-domain

https://www.pexels.com/

http://www.freeimages.com/

http://deathtothestockphoto.com/

https://search.creativecommons.org/

https://unsplash.com/

http://www.imcreator.com/free

http://getrefe.tumblr.com/

http://lockandstockphotos.com/

http://snapwiresnaps.tumblr.com/

http://jaymantri.com/

Resources page 2

<img>



  <img src="images/image.jpg" alt="if image does not display" title="description on hover">

Semantic IMG

  <figure>
    <img src="img/album-eno.jpg" alt="Another Green World album cover" title="Another Green World">
    <footer>
      <!-- copyright typically goes in a small tag in a footer -->
      <small class="copyright">© Island Records, 1975</small>
    </footer>
    <figcaption>
      Another Green World by Brian Eno.
      Cover art is detail from the Tom Phillips painting
      <cite>After Raphael</cite>)
    </figcaption>
  </figure>

<picture>

  • Container for Responsive Images
  • Browser loads the image that best fits the screen size
  • Example via html5rocks
<picture>
  <source 
    media="(min-width: 650px)"
    srcset="images/kitten-stretching.png">
  <source 
    media="(min-width: 465px)"
    srcset="images/kitten-sitting.png">
  <img 
    src="images/kitten-curled.png" 
    alt="a cute kitten">
</picture>

CSS: background-image

body {
  background-image: url('img/myimg.png');
  background-repeat:repeat;
  background-size:50px;
}

Data URL

HTML/CSS Images

By Jason Sigal

HTML/CSS Images

  • 3,380