Design Tips: What is the best picture format?
- jpg loses a little compared to bmp, but not much. Use it if your colour set’s above 64. It’s highly compressible and gives very good quality at maximum (12) against a small file size when compared to .tiff or .psd.
- bmp is uncompressed and even lossless compression won't compare.
- png is lossless and generally has good compression ratios, it supports alpha channels and transparency, but is not widely supported in graphics programs and browsers.
- gif is great for low colour images as the 256 colour limit keep file sizes well below other formats whilst maintaining good quality (if you don't need more than 8-bit colour).
- tiff, with LZW compression gives a quality image and is a well "behaved" format for printing. If you want to change the dpi it's best to use Photoshop.
The size you need to end up with determines the format to start with. If you plan on making large prints above 5x7 then you need to use a base picture with a larger frame size to avoid grain and fuzzy details.
In printing, consider that using 800x600px for an 8x10" print or 1280x1024 for an 11x17 print" realises about 75dpi (pixelated and jagged). For quality, print above 150dpi, and if possible 300dpi. So a 5x7" will need 1500x2100px and an 8x10" will need 2400x3000px. For display on your PC screen, run 100% quality in JPG format and use:
- 640x480 for prints up to 3x5".
- 800x600 for prints up to 8x10" if maximum detail is not absolutely necessary.
- 1024x768 for detailed 8x10" prints, or 1280x1024 for 11x17".
Larger frame sizes let you save more in .jpg than .bmp or .tiff, but it’s not good professionally or for working on. So keep the original, especially if it’s a .tiff or .psd (Photoshop), then you can work magic and save in the same quality. Otherwise the law of diminishing returns means you lose a bit of quality each time you modify and successively save (lossy) .jpg’s.
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