User:Dbenbenn/Image tutorial

Here are some technical details that I've learned in the last few months.

Slogans

• Higher resolution is always better.
• Repeated lossy compression is evil.
• Always keep the original.

Digital camera

• Set your digital camera to the highest resolution possible.
• Set the JPEG compression to the highest quality possible.

Cropping

• Always upload the original, uncropped image first. Someone else might want to crop it differently.
• Don't use Photoshop or the Gimp to crop a JPEG file. The remaining part of the image will lose quality. Instead, use jpegtran, which can do various lossless transformations.

Other

• Use pnmpsnr to verify that two images are identical, for example when converting TIFF to PNG.
• Use pngcrush to losslessly reduce the size of a PNG file.
• Use pnmcrop to crop a diagram to its bounding box.
• Choose a good name for your image.
  • Avoid CamelCase.
  • For an artwork, use the title.
  • Otherwise, use something descriptive.