id	summary	reporter	owner	description	type	status	priority	milestone	component	resolution	keywords	cc	parents
823	Ugly previews of scaled indexed images	saul		"Previews of images using an indexed color mapping can become very ugly if the original image needs to be scaled down. For example:

[[Image(http://barn.kerosenecow.net/mgoblin_media/media_entries/435/indexed-degradation.png)]]

This degradation is inherent to scaling indexed images and though the result may vary depending on the scaling algorithm used (NEAREST, BILINEAR, BICUBIC, or ANTIALIAS), scaling will always result in degradation. 

Of the file types that Mediagoblin supports, PNG and TIFF files may or may not use indexed color mapping, while GIF files always use indexed colors.

One way to improve the quality of such scaled previews is to convert the image to the RGB color space before scaling. 

"	defect	accepted	minor		programming		small