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.
Portable Network Graphic. PNG or Portable Network Graphic format is a graphic file format that uses lossless compression algorithm to store raster images. It uses 2 stage compression methods. It is frequently used as web site images rather than printing as it supports only the RGB color model. So CMYK color images cannot be saved as PNG image.