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	0.019
scatterplot	1	43.688	17.211	0.065
scatterplot	2	39.479	25.185	0.193
scatterplot	3	39.479	25.185	0.663
scatterplot	4	39.296	25.533	1.431
scatterplot	5	39.296	25.533	2.523
scatterplot	6	39.296	25.533	3.044
boxplot	-1	13.216	0.000	0.000
boxplot	0	12.225	7.500	0.018
boxplot	1	12.172	7.899	0.048
boxplot	2	11.864	10.227	0.105
boxplot	3	11.864	10.227	0.410
boxplot	4	11.346	14.151	0.856
boxplot	5	11.346	14.151	1.647
boxplot	6	11.346	14.151	2.084
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	0.168
persp	3	112.781	34.712	0.600
persp	4	111.905	35.219	1.292
persp	5	111.905	35.219	2.279
persp	6	111.905	35.219	2.726

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	0.191
scatterplot	1.0	19.061	63.880	0.562
scatterplot	2.3	19.061	63.880	0.561
scatterplot	6.0	19.061	63.880	0.561
scatterplot	16.0	15.228	71.143	1.265
scatterplot	32.0	11.081	79.001	1.167
scatterplot	64.0	6.250	88.156	0.879
boxplot	0.0	11.864	10.227	0.099
boxplot	1.0	6.976	47.218	0.501
boxplot	2.3	6.976	47.218	0.501
boxplot	6.0	6.976	47.218	0.502
boxplot	16.0	5.079	61.568	0.993
boxplot	32.0	4.491	66.016	0.882
boxplot	64.0	1.904	85.591	0.651
persp	0.0	112.781	34.712	0.169
persp	1.0	54.936	68.198	0.579
persp	2.3	54.936	68.198	0.579
persp	6.0	49.410	71.397	1.189
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.