JPEG vs TIFF - Version 2

I had been concerned about my first test being more a test of the CCD noise rather than JPEG vs TIFF artifacts. The scene was at night, in a relatively low light. The shutter speed was quite long, allowing any CCD noise to build up.

I decided to take an outdoors shot with a much faster shutter speed. I waited for a bright day, with almost no wind. However, I was unable to totally eliminate movement in the scene. Nevertheless, most photos you take will have some level of movement in them, so I think my selected scene is still quite valid.

I followed the exact same procedure as for my first test, so please refer to it for details.

All the photos were taken within 70secs (JPEG at 11:42:01, TIFF1 at 11:42:33, TIFF2 at 11:43:11). Here are the settings as stored in the JPEG:

FileName: C:\temp\tifftest\03180011.JPG FileSize: 1404 kBytes (1438519 Bytes) Date: 2002:03:18 11:42:00 (File Modification) Date: 2002:03:18 11:42:01 (Picture Shot) Quality: Fine Width x Height: 2048 x 1536 pixels Recording Mode: Single Shutter Program: Manual Control Flash Used/Mode/Intensity: No / Off / Normal Focusing Mode: Manual Focus Exposure Time: 1/320 sec. Aperture Stop: F5.6 Focal Length (Equiv.) Zoom: 7.13 mm (34 mm) 1.0 Digital Zoom: Off Exposure Comp. (Set.): None (None) Sharpness: Normal Saturation: Normal Contrast: Normal Light Metering: Multi White Balance: Manual Sensitivity: Normal Orientation: Normal ("Landscape") Bits per Pixel: 3.6 Distance (?): 254000 mm (254.00 m, 10000.00 inch, 833.33 feet, 277.78 yard) "Magic": 8:1 9:1 14:0 15:0 16:0 17:9175160(140,120) 18:16 19:16 Make, Model, Firmware: CASIO, QV-3000EX, Ver1.002 Data by DiCaInfo 1.4.0, (c) DiCaSoft, www.dicasoft.de

The scene:

JPEG vs TIFF1 comparison

Difference
	Mean:11 Mode:6 Max diff:231
Difference, Equalized Histogram

TIFF1 vs TIFF2 comparison

Difference
	Mean:9 Mode:4 Max diff:248
Difference, Equalized Histogram

A table of the proportion of pixel differences:

Proportions of pixel differences

Pixel Difference	Percent Below
	JPEG vs TIFF1	TIFF1 vs TIFF2
0	0.0	0.0
1	2.4	7.9
2	9.5	22.1
3	20.6	36.9
4	31.8	47.9
5	41.5	55.7
6	49.3	61.5
7	55.3	65.8
8	60.0	69.3
9	63.8	72.2
10	67.0	74.6
11	69.8	76.7
12	72.2	78.4
13	74.3	80.0
14	76.2	81.4
15	77.9	82.6
16	79.3	83.8
17	80.7	84.8
18	81.9	85.7
19	83.0	86.5
20	84.1	87.3
21	85.0	88.0
22	85.9	88.6
23	86.7	89.2
24	87.4	89.8
25	88.1	90.3
26	88.8	90.8
27	89.4	91.3
28	89.9	91.7
29	90.4	92.1
30	90.9	92.5
31	91.4	92.8
32	91.9	93.2
33	92.3	93.5
34	92.6	93.8
35	93.0	94.1
36	93.4	94.3
37	93.7	94.6
38	94.0	94.8
39	94.3	95.0
40	94.6	95.3
41	94.8	95.5
42	95.1	95.7
:	:	:
231	100.0 (largest JPEG vs TIFF difference)	100.0
248	100.0	100.0 (largest TIFF vs TIFF difference)

As in the first test, the TIFF1 vs TIFF2 errors peak sooner than the JPEG vs TIFF1 errors, indicating that overall there is a lesser amount of error in the TIFF images. Nevertheless, half the errors are less than 6 for the JPEG vs TIFF1, and half the errors are less than 4 for the TIFF1 vs TIFF2. There still isn't a significant amount of extra errors in the JPEG.

Conclusion

It is still my opinion that the TIFF1 vs TIFF2 comparison is an indication of the level of error present in every photo taken. Saving as JPEG does add an extra level of error, but it is still only a small proportion compared against that minimum error level.

As I concluded in my first test, I don't see any benefit to taking TIFF photos on the Casio QV-3000. Taking JPEG photos allows you to take six times as many photos in one-tenth the amount of time. Don't forget what you may miss as you wait the 20sec for the TIFF to save!

I've also noticed that the feared CCD noise probably did not impact on my first test. The error levels in this test in general were higher, probably due to motion in the scene.