PNGOUT

{{Short description|Command-line PNG optimiser}}

{{Multiple issues|

{{refimprove|date=October 2011}}

{{Notability|Products|date=April 2011}}

{{primary sources|date=April 2011}}

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{{Infobox software

| name = PNGOUT

| screenshot = PNGOUT Screenshot.PNG

| caption = Two runs of PNGOUT with randomization in Microsoft Windows

| author = Ken Silverman

| developer = Ken Silverman

| latest release version = {{Start date and age|2015|02|13}}{{cite web |url=http://www.advsys.net/ken/utils.htm |title=Ken Silverman's Utility Page |work=advsys.net |accessdate=January 15, 2018}}{{cite web |url=http://www.jonof.id.au/kenutils |title=JonoF's Games and Stuff : Ken Silverman's Utilities |work=jonof.id.au |accessdate=January 15, 2018}}

|released = {{Start date and age|2002|01|15}}

| operating system = Microsoft Windows

| genre = Image optimizer

| license = Freeware

| website = {{URL|http://advsys.net/ken/utils.htm}}

}}

PNGOUT is a freeware command line optimizer for PNG images written by Ken Silverman. The transformation is lossless, meaning that the resulting image is visually identical to the source image. According to its author, this program can often get higher compression than other optimizers by 5–10%.{{cite web|url=http://advsys.net/ken/utils.htm#pngout |title=PNGOUT project homepage |publisher=Advsys.net |date= |accessdate=2013-11-19}} It is possible to compress some inflated PNGs to a size below 1% of the original file.{{Citation|last=JoKalliauer|title=English: A Screenshot of Ken Silverman's PNGOUT optimizing|date=2019-01-30|url=https://commons.wikimedia.org/wiki/File:Screenshot_PNGOUT.PNG#filehistory|access-date=2019-01-30}}

PNGOUT was also available as a plug-in for the freeware image viewer IrfanView and can be enabled as an option when saving files. It allows editing of various PNGOUT settings via a dialog box.[http://www.irfanview.com/plugins.htm IrfanView PlugIns] PNGOUT integration was removed in IrfanView version 4.58 in favour of OptiPNG.[https://www.irfanview.com/history_old.htm History of IrfanView changes/versions]

In 2006, a commercial version of PNGOUT with a graphical user interface, known as PNGOUTWin, was released by Ardfry Imaging, a small company Silverman co-founded in 2005. There is also a freeware GUI frontend to PNGOUT available, known as PNGGauntlet.[http://pnggauntlet.com/ pnggauntlet.com]