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.
It's a lossless bitmap image format that is popular on the World Wide Web and elsewhere. PNG was largely developed to deal with some of the shortcomings of the GIF format and allows storage of images with greater color depth and other important information. A PNG image with an 8-bit transparency layer (top), overlayed onto a chequered background (bottom).