Image scrambling is a useful approach to protect image data by confusing the image and thus prevent it from being misused. The issues concerning the relationship among the adjacent pixels of the scrambled image, the weakness of visual leakage, and similar histogram plots being produced, all affect the image scrambling process. This paper is aimed at determining the iteration level that is extracted from a secure key and a key mask for building a scrambling table which is used in the scrambling processes and modifying the pixel colour values. The technique begins by modified pixel colour values. These pixel colour values are then scrambled by reduce or the increase (modified) the pixel colour values in the image between the range of the colour (0 to 255) by using a vertical and horizontal scrambling method based on a scrambling table. The experimental results of the paper show that the pixel colour values scrambling technique has reduced the relationship among the image elements. This occurs because the entropy value of the scrambled images has increased and the correlation value is lower. Moreover, the scrambling degree of the scrambling technique has larger values for the scrambled image. Subsequently, the pixel colour value modification in the technique helps to confuse and amend the pixel colour values of the scrambled image to produce a different histogram plot when compared with plots made from the original images.