JPEG Image Size & Quality
 Standard Test Scene |
The Optio S allows you to select image size and JPEG quality separately. For image size you have the following options; 2048 x 1536, 1600 x 1200, 1024 x 768 and 640 x 480. For JPEG quality there are three levels represented by one, two or three stars (best). Note that the Optio S does not provide a RAW or TIFF output.
To give an impression of what some of the combinations of image size and quality produce the table below is a cross reference of some of them:
- 2048 x 1536
- 2048 x 1536
- 2048 x 1536
- 1600 x 1200
- 1024 x 768
Images below are cropped 240 x 100 area of the image magnified
200% (nearest neighbour).
| 2048 x 1536 | |
| |
 2,122 KB |
| |
 1,005 KB |
| |
 698 KB |
| 1600 x 1200 | |
| |
 1,160 KB |
| 1024 x 768 | |
| |
 550 KB |
With the Optio S JPEG artifacts start to creep in (subtly) at the two star setting, three star is virtually artifact free but very large for a three megapixel image. Most users will probably use the two star setting and compromise on the occasional edge detail artifact. The downsampling algorithm (probably simply nearest neighbour) used in the Optio S also generates rather jagged looking images (not ideal).
Image parameters
The Optio S provides a surprisingly wide range of image processing parameter adjustment. These parameters control the image processing applied before it is converted to its output format. The camera provides five levels of contrast, saturation and sharpness. Below you will find examples of these parameters at their neutral (0) and extreme settings (-2 and +2). What's even more surprising is that this is more than it's bigger brother the Optio 550 provides, and that's supposed to be a prosumer camera.
Image parameters: Contrast
| Contrast | Luminosity histogram | |
| -2 |  |
 |
| 0 |  |
 |
| +2 |  |
 |
Image parameters: Saturation
| Saturation | 100% crop | |
| -2 |  |
 |
| 0 | |
 |
| +2 |  |
 |
Image parameters: Sharpness
| Sharpness, 100% crop | |
| -2 |  |
| 0 |  |
| +2 |  |
