tinypng() Benchmarks

1 Overview

This document benchmarks the tinypng() function from the tinyimg package across different optimization levels (0-6). We test with three types of plots:

1. A scatterplot based on the penguins dataset
2. A simple boxplot (simpler graphics)
3. A complex 3D perspective plot (more complex graphics)

For each optimization level, we measure:

• File size reduction (in KB and percentage)
• Time taken for optimization

2 Test Plots

First, we create test plots using the png() device:

3 Benchmarks

Now let’s optimize these plot files at different levels and measure the results:

#> scatterplot-1.png -> scatterplot_level_0.png | 52.8 KB -> 45.1 KB (-14.6%)
#> scatterplot-1.png -> scatterplot_level_1.png | 52.8 KB -> 43.7 KB (-17.2%)
#> scatterplot-1.png -> scatterplot_level_2.png | 52.8 KB -> 39.5 KB (-25.2%)
#> scatterplot-1.png -> scatterplot_level_3.png | 52.8 KB -> 39.5 KB (-25.2%)
#> scatterplot-1.png -> scatterplot_level_4.png | 52.8 KB -> 39.3 KB (-25.5%)
#> scatterplot-1.png -> scatterplot_level_5.png | 52.8 KB -> 39.3 KB (-25.5%)
#> scatterplot-1.png -> scatterplot_level_6.png | 52.8 KB -> 39.3 KB (-25.5%)
#> boxplot-1.png -> boxplot_level_0.png | 13.2 KB -> 12.2 KB (-7.5%)
#> boxplot-1.png -> boxplot_level_1.png | 13.2 KB -> 12.2 KB (-7.9%)
#> boxplot-1.png -> boxplot_level_2.png | 13.2 KB -> 11.9 KB (-10.2%)
#> boxplot-1.png -> boxplot_level_3.png | 13.2 KB -> 11.9 KB (-10.2%)
#> boxplot-1.png -> boxplot_level_4.png | 13.2 KB -> 11.3 KB (-14.2%)
#> boxplot-1.png -> boxplot_level_5.png | 13.2 KB -> 11.3 KB (-14.2%)
#> boxplot-1.png -> boxplot_level_6.png | 13.2 KB -> 11.3 KB (-14.2%)
#> persp-1.png -> persp_level_0.png | 172.7 KB -> 125.5 KB (-27.3%)
#> persp-1.png -> persp_level_1.png | 172.7 KB -> 114.3 KB (-33.8%)
#> persp-1.png -> persp_level_2.png | 172.7 KB -> 112.8 KB (-34.7%)
#> persp-1.png -> persp_level_3.png | 172.7 KB -> 112.8 KB (-34.7%)
#> persp-1.png -> persp_level_4.png | 172.7 KB -> 111.9 KB (-35.2%)
#> persp-1.png -> persp_level_5.png | 172.7 KB -> 111.9 KB (-35.2%)
#> persp-1.png -> persp_level_6.png | 172.7 KB -> 111.9 KB (-35.2%)

Plot	Level	Size_KB	Reduction_pct	Time_sec
scatterplot	-1	52.770	0.000	0.000
scatterplot	0	45.083	14.566	0.020
scatterplot	1	43.688	17.211	0.064
scatterplot	2	39.479	25.185	0.194
scatterplot	3	39.479	25.185	0.666
scatterplot	4	39.296	25.533	1.435
scatterplot	5	39.296	25.533	2.528
scatterplot	6	39.296	25.533	3.054
boxplot	-1	13.216	0.000	0.000
boxplot	0	12.225	7.500	0.017
boxplot	1	12.172	7.899	0.040
boxplot	2	11.864	10.227	0.101
boxplot	3	11.864	10.227	0.411
boxplot	4	11.346	14.151	0.858
boxplot	5	11.346	14.151	1.664
boxplot	6	11.346	14.151	2.089
persp	-1	172.745	0.000	0.000
persp	0	125.522	27.337	0.020
persp	1	114.313	33.825	0.058
persp	2	112.781	34.712	0.169
persp	3	112.781	34.712	0.602
persp	4	111.905	35.219	1.295
persp	5	111.905	35.219	2.287
persp	6	111.905	35.219	2.736

Note: The optimization level of -1 represents the raw, unoptimized file (not a valid value for the level argument of tinypng()). This helps show the effect of level = 0 more clearly.

4 Lossy Optimization

#> scatterplot-1.png -> scatterplot_lossy_0.png | 52.8 KB -> 39.5 KB (-25.2%)
#> scatterplot-1.png -> scatterplot_lossy_1.png | 52.8 KB -> 19.1 KB (-63.9%)
#> scatterplot-1.png -> scatterplot_lossy_2_3.png | 52.8 KB -> 19.1 KB (-63.9%)
#> scatterplot-1.png -> scatterplot_lossy_6.png | 52.8 KB -> 19.1 KB (-63.9%)
#> scatterplot-1.png -> scatterplot_lossy_16.png | 52.8 KB -> 15.2 KB (-71.1%)
#> scatterplot-1.png -> scatterplot_lossy_32.png | 52.8 KB -> 11.1 KB (-79.0%)
#> scatterplot-1.png -> scatterplot_lossy_64.png | 52.8 KB -> 6.2 KB (-88.2%)
#> boxplot-1.png -> boxplot_lossy_0.png | 13.2 KB -> 11.9 KB (-10.2%)
#> boxplot-1.png -> boxplot_lossy_1.png | 13.2 KB -> 7.0 KB (-47.2%)
#> boxplot-1.png -> boxplot_lossy_2_3.png | 13.2 KB -> 7.0 KB (-47.2%)
#> boxplot-1.png -> boxplot_lossy_6.png | 13.2 KB -> 7.0 KB (-47.2%)
#> boxplot-1.png -> boxplot_lossy_16.png | 13.2 KB -> 5.1 KB (-61.6%)
#> boxplot-1.png -> boxplot_lossy_32.png | 13.2 KB -> 4.5 KB (-66.0%)
#> boxplot-1.png -> boxplot_lossy_64.png | 13.2 KB -> 1.9 KB (-85.6%)
#> persp-1.png -> persp_lossy_0.png | 172.7 KB -> 112.8 KB (-34.7%)
#> persp-1.png -> persp_lossy_1.png | 172.7 KB -> 54.9 KB (-68.2%)
#> persp-1.png -> persp_lossy_2_3.png | 172.7 KB -> 54.9 KB (-68.2%)
#> persp-1.png -> persp_lossy_6.png | 172.7 KB -> 49.4 KB (-71.4%)
#> persp-1.png -> persp_lossy_16.png | 172.7 KB -> 35.3 KB (-79.6%)
#> persp-1.png -> persp_lossy_32.png | 172.7 KB -> 29.5 KB (-82.9%)
#> persp-1.png -> persp_lossy_64.png | 172.7 KB -> 6.6 KB (-96.2%)

Plot	Lossy	Size_KB	Reduction_pct	Time_sec
scatterplot	0.0	39.479	25.185	0.192
scatterplot	1.0	19.061	63.880	0.560
scatterplot	2.3	19.061	63.880	0.559
scatterplot	6.0	19.061	63.880	0.559
scatterplot	16.0	15.228	71.143	1.266
scatterplot	32.0	11.081	79.001	1.167
scatterplot	64.0	6.250	88.156	0.880
boxplot	0.0	11.864	10.227	0.100
boxplot	1.0	6.976	47.218	0.502
boxplot	2.3	6.976	47.218	0.500
boxplot	6.0	6.976	47.218	0.501
boxplot	16.0	5.079	61.568	0.999
boxplot	32.0	4.491	66.016	0.884
boxplot	64.0	1.904	85.591	0.651
persp	0.0	112.781	34.712	0.170
persp	1.0	54.936	68.198	0.578
persp	2.3	54.936	68.198	0.578
persp	6.0	49.410	71.397	1.186
persp	16.0	35.275	79.580	1.041
persp	32.0	29.479	82.935	0.901
persp	64.0	6.574	96.194	0.684

A visual comparison of the lossy optimization results:

5 Visualization

Note that for the lossy optimization benchmarks, we first did the lossy optimization and then applied the default level of lossless optimization on top of it. The outcome is the combination of both optimizations.

The dashed vertical line in the lossy optimization plots indicates the JND (just noticeable difference) threshold of 2.3.