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.
Key difference: PNG stands for Portable Network Graphics. It was created as an improved and non-patented replacement for Graphics Interchange Format (GIF). JPG is the file format for a JPEG image. JPEG is the most commonly used format for photographs. It is specifically good for color photographs or for images with many blends or gradients.