The libmng homepage The libmng community on SourceForge The official MNG homepage The official PNG homepage

<< prev


next >>

Based on the PNGsuite.

The following samples test various delta-image variations on grayscale targets without an alpha channel.

In each sample the top row of images is displayed against a white background to show the original image that is used in delta-operations below it. A background for the remaining canvas is generated from a grayscale image with respectively 1,2,4,8 and 16 bits bit_depth (subsequent samples).

Below the original images, the first row shows a pixel-replace (4) operation and the second row shows a pixel-addition (1) operation.

The results will look bizar in certain cases!

The left side of each sample shows a screenshot of what the right side should look like. If they do not match, your MNG decoder doesn't handle delta-image variations very well. Note that this will be the case for implementations using libmng-1.0.4 or older!






Some or all of the following images were used:

basn6a16 & basi6a16 - 3x16 bits rgb color + 16 bit alpha-channel
basn6a08 & basi6a08 - 3x8 bits rgb color + 8 bit alpha-channel
basn4a16 & basi4a16 - 16 bit grayscale + 16 bit alpha-channel
basn4a08 & basi4a08 - 8 bit grayscale + 8 bit alpha-channel
basn3p08 & basi3p08 - 8 bit (256 color) paletted
basn3p04 & basi3p04 - 4 bit (16 color) paletted
basn3p02 & basi3p02 - 2 bit (4 color) paletted
basn3p01 & basi3p01 - 1 bit (2 color) paletted
basn2c16 & basi2c16 - 3x16 bits rgb color
basn2c08 & basi2c08 - 3x8 bits rgb color
basn0g16 & basi0g16 - 16 bit (64k level) grayscale
basn0g08 & basi0g08 - 8 bit (256 level) grayscale
basn0g04 & basi0g04 - 4 bit (16 level) grayscale
basn0g02 & basi0g02 - 2 bit (4 level) grayscale
basn0g01 & basi0g01 - black & white

Samples on this page are Copyright © G. Juyn
Images used in the samples are Copyright © Willem van Schaik

<< prev


next >>