codec: gif format (best effort comparison)

Should definitely be included as major legacy web format, despite palette
restrictions not present in other competitors.  Colour quantisation can be
graded as quality loss similar to 4:2:0 subsampling.

diff --git a/codec.inc.pl b/codec.inc.pl
index ab7e841e44a259392caf235bd1e3d727dacbfba9..6b6b4e09d0e582e8370dd303b87ddc8183efeb73 100644 (file)
--- a/codec.inc.pl
+++ b/codec.inc.pl
@@ -5,6 +5,10 @@ codec => {
                name => '<abbr title="Joint Photographic Experts Group">JPEG</abbr>',
                available => 1992,
        },
+       gif => {
+               name => '<abbr title="Graphics Interchange Format">GIF</abbr>',
+               available => 1987,
+       },
        png => {
                name => '<abbr title="Portable Network Graphics">PNG</abbr>',
                available => 1996,
@@ -38,6 +42,7 @@ feature => {
                name => 'compression (photo)',
                score => {
                        jpeg => 3,
+                       gif  => 1,
                        png  => 1,
                        jp2k => 4,
                        webp => 3,
@@ -52,6 +57,7 @@ feature => {
                name => 'thumbnails',
                score => {
                        jpeg => 2,
+                       gif  => 1,
                        png  => 1,
                        jp2k => 3,
                        webp => 4,
@@ -65,6 +71,7 @@ feature => {
                name => 'medium fidelity',
                score => {
                        jpeg => 3,
+                       gif  => 1,
                        png  => 1,
                        jp2k => 4,
                        webp => 3,
@@ -78,6 +85,7 @@ feature => {
                name => 'high fidelity',
                score => {
                        jpeg => 3,
+                       gif  => 1,
                        png  => 2,
                        jp2k => 4,
                        webp => 2,
@@ -91,6 +99,7 @@ feature => {
                name => 'lossless',
                score => {
                        jpeg => 1,
+                       gif  => 1,
                        png  => 2,
                        jp2k => 4,
                        webp => 3,
@@ -103,6 +112,7 @@ feature => {
                name => 'compression (other images)',
                score => {
                        jpeg => 2,
+                       gif  => 1,
                        png  => 3,
                        jp2k => 2,
                        webp => 4,
@@ -116,6 +126,7 @@ feature => {
                name => 'lossy non-photographic',
                score => {
                        jpeg => 2,
+                       gif  => 2,
                        png  => 3,
                        jp2k => 2,
                        webp => 4,
@@ -128,6 +139,7 @@ feature => {
                name => 'lossless non-photographic',
                score => {
                        jpeg => 1,
+                       gif  => 1,
                        png  => 4,
                        jp2k => 2,
                        webp => 5,
@@ -140,6 +152,7 @@ feature => {
                name => 'mixed photo/nonphoto',
                score => {
                        jpeg => 2,
+                       gif  => 1,
                        png  => 2,
                        jp2k => 2,
                        webp => 3,
@@ -151,6 +164,7 @@ feature => {
        speed => {
                score => {
                        jpeg => 5,
+                       gif  => 4,
                        png  => 4,
                        jp2k => 3,
                        webp => 4,
@@ -165,6 +179,7 @@ feature => {
                name => 'single-core encode',
                score => {
                        jpeg => 5,
+                       gif  => 3, # palette conversion
                        png  => 3,
                        jp2k => 4,
                        webp => 4,
@@ -178,6 +193,7 @@ feature => {
                name => 'single-core decode',
                score => {
                        jpeg => 5,
+                       gif  => 5,
                        png  => 5,
                        jp2k => 4,
                        webp => 5,
@@ -191,6 +207,7 @@ feature => {
                name => 'pararellizable',
                score => {
                        jpeg => 2,
+                       gif  => 2,
                        png  => 2,
                        jp2k => 4,
                        webp => 2,
@@ -202,6 +219,7 @@ feature => {
        limits => {
                score => {
                        jpeg => 3,
+                       gif  => 2,
                        png  => 4,
                        jp2k => 5,
                        webp => 2,
@@ -216,6 +234,7 @@ feature => {
                name => 'maximum image dimensions',
                score => {
                        jpeg => 3,
+                       gif  => 3,
                        png  => 4,
                        jp2k => 5,
                        webp => 1,
@@ -225,6 +244,7 @@ feature => {
                },
                data => {
                        jpeg => '65k²',  # 2**16
+                       gif  => '65k²',  # 2**16
                        png  => '2G²',   # 2**31
                        jp2k => '4G²',   # 2**32
                        webp => '16k²',  # 2**14
@@ -238,6 +258,7 @@ feature => {
                name => 'precision (max. bit depth)',
                score => {
                        jpeg => 2,
+                       gif  => 2,
                        png  => 4,
                        jp2k => 5,
                        webp => 2,
@@ -247,6 +268,7 @@ feature => {
                },
                data => {
                        jpeg => 8,
+                       gif  => 8,
                        png  => 16,
                        jp2k => 38,
                        webp => 8,
@@ -260,6 +282,7 @@ feature => {
                name => 'can do (lossy) 4:4:4',
                score => {
                        jpeg => 'y',
+                       gif  => 'y',
                        png  => 'y',
                        jp2k => 'y',
                        webp => 'n',
@@ -273,6 +296,7 @@ feature => {
                name => 'wide gamut/HDR',
                score => {
                        jpeg => 'n',
+                       gif  => 'n',
                        png  => 'y',
                        jp2k => 'y',
                        webp => 'n',
@@ -286,6 +310,7 @@ feature => {
                name => 'maximum number of channels',
                score => {
                        jpeg => 2,
+                       gif  => 1,
                        png  => 2,
                        jp2k => 5,
                        webp => 2,
@@ -295,6 +320,7 @@ feature => {
                },
                data => {
                        jpeg => 4, # cmyk
+                       gif  => 3,
                        png  => 4, # cmyk
                        jp2k => 2**15,
                        webp => 4,
@@ -306,6 +332,7 @@ feature => {
        features => {
                score => {
                        jpeg => 2,
+                       gif  => 2,
                        png  => 3,
                        jp2k => 4,
                        webp => 2,
@@ -320,6 +347,7 @@ feature => {
                name => 'supports animation',
                score => {
                        jpeg => 2,
+                       gif  => 'y',
                        png  => 4,
                        jp2k => 2,
                        webp => 'y',
@@ -338,6 +366,7 @@ feature => {
                name => 'progressive decoding',
                score => {
                        jpeg => 4,
+                       gif  => 2,
                        png  => 2,
                        jp2k => 5,
                        webp => 'n',
@@ -351,6 +380,7 @@ feature => {
                name => 'alpha transparency',
                score => {
                        jpeg => 'n',
+                       gif  => 3,
                        png  => 'y',
                        jp2k => 'y',
                        webp => 'y',
@@ -358,12 +388,16 @@ feature => {
                        avif => 'y',
                        jxl  => 'y',
                },
+               data => {
+                       gif => '1 bit',
+               },
        },
        depthmap => {
                parent => 'features',
                name => 'depth map',
                score => {
                        jpeg => 'n',
+                       gif  => 'n',
                        png  => 'n',
                        jp2k => 'n',
                        webp => 'n',
@@ -377,6 +411,7 @@ feature => {
                name => 'overlays (layers)',
                score => {
                        jpeg => 'n',
+                       gif  => 'y',
                        png  => 'n',
                        jp2k => 'n',
                        webp => 'n',
@@ -390,6 +425,7 @@ feature => {
                name => 'authoring workflow suitability',
                score => {
                        jpeg => 2,
+                       gif  => 2,
                        png  => 3,
                        jp2k => 3,
                        webp => 2,
@@ -403,7 +439,8 @@ feature => {
                name => 'generation loss resilience',
                score => {
                        jpeg => 4,
-                       png  => 'n/a',
+                       png  => 0,
+                       gif  => 0,
                        jp2k => 3,
                        webp => 2,
                        heic => 3,
@@ -411,6 +448,7 @@ feature => {
                        jxl  => 4,
                },
                data => {
+                       gif  => 'n/a',
                        png  => 'n/a',
                },
        },
@@ -419,6 +457,7 @@ feature => {
                name => 'lossless JPEG recompression',
                score => {
                        jpeg => 0,
+                       gif  => 'n',
                        png  => 'n',
                        jp2k => 'n',
                        webp => 'n',
@@ -434,8 +473,8 @@ feature => {
                name => 'royalty-free',
                score => {
                        jpeg => 5,
-                       png  => 5,
                        gif  => 5, # patents expired
+                       png  => 5,
                        jp2k => 3, # specs not freely available
                        webp => 4, # submarine risk
                        heic => 'n', # patents enforced

diff --git a/codec.plp b/codec.plp
index 27a6cb73960bd54f1d7f88f8177239d4aa41598f..35b97ed30d5bb29b0b0cf3aa0b68197682238f37 100644 (file)
--- a/codec.plp
+++ b/codec.plp
@@ -22,7 +22,7 @@ my %BOOLSCORE = (y => 5, n => 1);
 
 <div class="section">
 <table class="mapped">
-       <col><colgroup span=2><colgroup span=2><colgroup span=3>
+       <col><colgroup span=3><colgroup span=2><colgroup span=3>
 <thead><tr><th rowspan=2>feature
 <:
 my @codecs = sort {