Image 1 Graph
Here is the original.
Size: 2936KB
Its .jpg and is 1920 x 2560
Summary: As the graph suggests the dithering did not have a huge impact on this image. My guess for this reason is because there are only about 4 different strong colours in the picture (green black grey white). Also the transitions between these colours are very sharp which would reduce the need for dithering. The optimum image was the non-dithered image with 50 colours. Any lower and the quality became unacceptable and any higher and the size became too big.
The file size difference between the original and the optimum image is: 2689KB or 8.4% of the original filesize.
Size: 427KB
Dithering: Yes
Quality: The quality is at its maximum for this, but the size can still be cut down without losing any noticable quality.Dithering has no visable effect. There is also very little difference between this and the original .jpg version of this.
No. of Colors: 256
Size: 408KB
Dithering: No
Quality: The quality is at its maximum for this, but the size can still be cut down without losing any noticable quality.Dithering has no visable effect. There is also very little difference between this and the original .jpg version of this.
No. of Colors: 100Size: 311KB
Dithering: Yes
Quality: This is the best quality versus size image I could get. If any more colors were added, they wouldn't be easily noticed and the size would just grow. There is extremly little difference between this and the non-dithered version.
No. of Colors: 100Size: 311KB
Dithering: No
Quality: Excellent quality! Adding any more colours resulted in very little noticable difference but just an increas in filesize. There is extremly little difference between this and the dithered version.
No. of Colors: 50Size: 249KB
Dithering:Yes
Quality: The quality is good although a slight increase of colors wouldn't do any harm. It is a small enough file if you were tight on bandwith. The non-dithered version of this had little difference.
No. of Colors: 50Size: 247KB
Dithering: No
Quality: The quality is good although a slight increase of colors wouldn't do any harm.. It is a small enough file if you were tight on bandwith. The dithered version of this had little difference. I found that this image was the best size versus quality.
No. of Colors: 20Size: 141KB
Dithering: Yes
Quality:Poor: I felt that this image had not enough quality. Dithering had a nice effect on the image.
No. of Colors: 20Size: 135KB
Dithering: No
Quality: Poor I felt that this image had not enough quality.
No. of Colors: 10Size: 111KB
Dithering: Yes
Quality:Poor: I felt that this image had not enough quality. Dithering had a nice effect on the image.
No. of Colors: 10Size: 98KB
Dithering: No
Quality: Very poor. I felt that this image had not enough quality.
