1. Common Bitmap Image File Types
bitmap = raster = pixel graphics (versus vector graphics)
File Size vs. Image Quality

2. JPEG, JPE, JPG Best for full-color photographs Lossy compression
Highly compressed
Encoded in full color
Lossy compression
Loses quality as you edit and save
JPG most universally used lossy format

3. GIF Good for fewer colors, such as a logo
Indexed format – uses up to 256 colors
256 = 28 referred to as 8-bit color
Advantages
Transparency
Animation
Poor choice for photographs; tr = can make an icon with clear background; pixels either fully transparent or not at all

4. PNG Two modes Full and partial transparency Doesn’t support animation
Indexed
Full color
Lossless compression
Full and partial transparency
Doesn’t support animation
full-color like jpg but not as efficient; indexed – as efficient as gif but can support more than 256 colors

5. XCF GIMP native format Saves layers and other information
Add gx or bx2 to file name to compress: xcf.gz or xcf.bz2

6. TIFF, TIF Full-color Non-lossy & lossless Various “dialects” of TIFF
Good for keeping originals
Handles a wider range of colors: can handle 16 bits per color channel

7. RAW BMP PSD ICO Proprietary camera formats
Windows format; huge files; no advantage over PNG or TIFF
PSD
Adobe’s proprietary format
ICO
Windows Icon format

8. Image File Characteristics
GIF, JPEG, PNG, TIFF

9. GIF

10. GIF

11. JPEG, JPG, JPE

12. PNG

13. TIFF, TIF

14. Compression

15. Bitmap File Formats

16. Bitmap, Raster, Pixel-based Images
Pixels Galore
Bitmap, Raster, Pixel-based Images