Z-Scores and Pearson Correlation: If we have scores that are expressed as standardized scores -- Z-Scores with a mean of zero and a variance of one -- then the formula for the Pearson Correlation becomes particularly simple.
PNG Formats. .PNG files in logo design and when you should use them. PNG is an acronym for Portable Network Graphics. PNGs are bitmpapped (raster/pixel based) image formats that can be used instead of GIF images or JPGs. PNG logo images are superior to other pixel based formats as they employ a âlosslessâ data compression system.
PNG also preserves transparency in grayscale and RGB images. So letâs take at how each of the file formats fare using two different images. Iâve saved a logo and a photograph using Photoshopâs âSave For Web and Devicesâ command. Weâll start with the logo which is made up of only a few colors.