Performance tests

I made some performance comparition tests using three programs: RIOT, IrfanView and XNView.

The versions used are the latest available:
RIOT 0.4 beta
IrfanView 4.25
XNView  1.97.2

Here are the results:

Test #1
Batch mode: add all supported images from drive D including sub-folders

(~41,600 images) to the list

1. RIOT: 5 seconds at cold start, and less than 2 seconds if the drive was used/scanned
2. XNView: 15 seconds, no change the seconds time
3. IrfanView: 35 seconds, no change the seconds time

Test #2
Batch mode: re-compress/optimize 85 JPEG images from a single folder

1. RIOT: 31 seconds
2. IrfanView: 47 seconds
3. XNView: 48 seconds

Test #3
Batch mode: re-compress/optimize 85 JPEG images from a single folder
and resize them to 640 x 480 pixels

1. RIOT: 30 seconds
2. IrfanView: 30 seconds
3. XNView: 41 seconds

Parameters used: quality 80, default chroma (medium), Optimal Huffman
tables (standard optimized)
For resize: Bilinear filter (triangle for IrfanView)

Test #4
Batch mode: save 16 JPEG images from a folder to PNG with maximum compression

1. RIOT: 14 seconds
2, IrfanView: 19 seconds
3. XNView: 20 seconds

Test #5
Batch mode: save 16 JPEG images from a folder to PNG with maximum compression
and resize them to 640 x 480 pixels

1. RIOT: 11 seconds
2, IrfanView: 14 seconds
3. XNView: 15 seconds

Parameters used for resize: Bilinear filter (triangle for IrfanView)

The GIF test was non-conclusive because the quantization implementations in IrfanView and XNView are unknown.

As you can see RIOT stands out as the clear winner among these three in terms of speed.