JPEG Image Size & Quality

The 812 has four fixed image size / quality combinations, each combination is represented by a number of stars. The 812 does not have an uncompressed mode, nor does it allow you to select your own combination of image size / quality.

Standard Test Scene

To provide an impression of each image size / quality combination you will find a sample of each below.

  • (2272 x 1712 JPEG 5:1)
  • (2272 x 1712 JPEG 10:1)
  • (1136 x 856 JPEG 15:1)
  • (1136 x 856 JPEG 30:1)

Images below are cropped 240 x 100 area of the image magnified 200% (nearest neighbour).

2272 x 1712

2,618 KB
2272 x 1712

1,268 KB
1136 x 856

591 KB
1136 x 856

275 KB

I was VERY surprised to see the amount of JPEG artifacts visible in the and images. Take the 1136 x 856 image as an example, it weighs in at 591 KB. At this JPEG file size and resolution we would expect a very high quality image without any artifacts, yet artifacts are clearly visible. As an experiment I took one of the 2272 x 1712 images, half sized it and saved it as a JPEG from Photoshop (quality 9). This new test JPEG was only 342 KB in size and yet exhibits almost no artifacts.

1136 x 856, 591 KB JPEG
Created by the HP 812
1136 x 856, 342 KB JPEG
Created by Photoshop (from an 812 image)

What does this mean? In simple terms it means that you are not getting "good storage value". You are storing (on your limited size SD card) a large file size image which doesn't deliver clean artifact free image quality. Although artifacts are not visible in the 2272 x 1712 images I'm sure that what we have discovered here means that they could have been smaller (file size) and still delivered the same JPEG quality.