PSD files are photoshop "work in progress" files. Other than the results of editing, you get out exactly what you put into it. If you want the files to be lossy, you make photoshop lose whatever you want it to. Otherwise, you don't, and nothing gets lost, making it lossless.
they are lossless...
Lossy
lossless
shush
plane waves in lossy dielectrics
lossless
Lossless. Compression techniques do not remove detail from the image.
Lossy= You lose somedata Lossless= You dont
GIF is a lossless compression introduced by CompuServe in 1987 using Lempel-Ziv-Welch (LZW) lossless data compression.
Pict files can use 2 different forms of compression. 1- RLE Compression (the default) is lossless. 2- JPEG compression (only on some systems/graphics programmes) is lossy.
Adobe Photoshop :)save images with layers in .psd format :)
Compression methods are used for images compression and most common compressions are JPEG which is lossy (you can lost some details or quality of image), LZW which is lossless, RLE and ZIP also lossless compressions.