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.
If you'll be using a logo with solid colors as your profile picture, PNG may offer the best quality and prevent noise from appearing in your image. If you size your image to precisely fit Facebook's 180-by-180-pixel image area, either format should be reasonably small in size.