Difference between revisions of "PNG"
(New page: Description Usage Benefits Shortfalls How to Index) |
(→Transparency, decals, and PNG files) |
||
| (4 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
| − | + | = PNG file format = | |
| + | == Gamma Problem Saving PNG out of Photoshop == | ||
| + | [http://www.hash.com/forums/index.php?s=&showtopic=40012&view=findpost&p=350913 Source]: Yves Poissant addressed problems saving PNG from Photoshop a couple of years ago. It seems Photoshop (and perhaps other programs) sets the gamma of png images in some strange way. I think on Windows, the gamma is set to 2.2. Yves suggested removing the gamma information altogether using a program like PngCrush ( http://pmt.sourceforge.net/pngcrush/ ). | ||
| − | + | You can also use IrfanView to gamma correct a png image. Open the image in IrfanView and go to Image > Color Corrections. Then set "Gamma Correction" to 1.00. | |
| + | You can also Batch correct a bunch of png images at once. Open IrfanView and go to Fle > batch Conversion. For "Output Format", choose "png". Then hit the "Advanced" button. Then check the box for "Gamma Correction" and enter a value. | ||
| + | http://www.irfanview.com/ | ||
| − | + | The problem is more widespread in the web browser arena. Here is a brief overview of the problem web browsers have with correctly rendering png images. http://morris-photographics.com/photoshop/articles/png-gamma.html | |
| + | == Transparency, decals, and PNG files == | ||
| − | [ | + | PNG files with transparency sometimes do not render correctly. For PNG files, [http://www.hash.com/forums/index.php?s=&showtopic=39316&view=findpost&p=352301 mtpeak reports]: Open the image in gimp and resave with the "save background color" option unchecked. You can also just set the key color in the image properties. |
| − | + | TGA files work fine. | |
| − | |||
| − | |||
Latest revision as of 09:49, 25 March 2012
PNG file format
Gamma Problem Saving PNG out of Photoshop
Source: Yves Poissant addressed problems saving PNG from Photoshop a couple of years ago. It seems Photoshop (and perhaps other programs) sets the gamma of png images in some strange way. I think on Windows, the gamma is set to 2.2. Yves suggested removing the gamma information altogether using a program like PngCrush ( http://pmt.sourceforge.net/pngcrush/ ).
You can also use IrfanView to gamma correct a png image. Open the image in IrfanView and go to Image > Color Corrections. Then set "Gamma Correction" to 1.00.
You can also Batch correct a bunch of png images at once. Open IrfanView and go to Fle > batch Conversion. For "Output Format", choose "png". Then hit the "Advanced" button. Then check the box for "Gamma Correction" and enter a value. http://www.irfanview.com/
The problem is more widespread in the web browser arena. Here is a brief overview of the problem web browsers have with correctly rendering png images. http://morris-photographics.com/photoshop/articles/png-gamma.html
Transparency, decals, and PNG files
PNG files with transparency sometimes do not render correctly. For PNG files, mtpeak reports: Open the image in gimp and resave with the "save background color" option unchecked. You can also just set the key color in the image properties.
TGA files work fine.
