User:Dbenbenn/Image tutorial

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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.