Table of Contents
This is an introduction to the topic of discussion and an exploration of its potential implications. An exploration of the possibilities of this topic and the potential outcomes that could result is underway.
Visual Perception and Bottom Up Processing
Contrast and Contour with Color
Motion and size
Instance of Design
Recommendations for Design
Visual perception refers to the way we perceive the world through the light entering our eyes. Since the dawn of time, humans have had to learn to distinguish between signals and noise in order to be able to adapt to changing environments. Because humans can distinguish between the targeted signals and background noise, these signals are crucial to cognition. This review examines theories, concepts, and analyses the key aspects of signal processing. These concepts have profound implications when applied to user experience. It can be used to distinguish between an effective and usable interface. Examining the Boston Citgo sign is a great example of how user experience can be impacted by a good understanding of visual perception and the biology of the eye.
DiscussionVisual perception and bottom-up processing It allows us to recognize and interpret signals from the environment, and to take appropriate precautions or actions when these changes occur. Although the nervous and brain are skilled in interpreting signals, sometimes they are unclear. Signals are usually ambiguous. Knowing the strength will enable you to discriminate between noise and signals. Bottom-Up Processing. Because of its many connections with the optic nerve, the human eye is sensitive to signals. The cornea allows light to enter the eye, where it is focused onto the photoreceptors. The retina is composed of rods and cones. For high resolution and color vision, the fovea is “densely packed” with cones. The rods are located near the periphery and help in processing light and moving in different environments. One glance can be enough to process many signals in one go. The human eye is capable of detecting contrast, color and contour in one glance. This will all be explained in the sections below.
Contrast and color contrast are key factors in determining signal strength. Contrast describes the difference between a stimulus and the stimuli surrounding it. It perceives changes between the background, foreground, and background. The brain perceives the stimulus as a change in the background and foreground, just like our brains do with signals. To produce the best signal, it is important to strike a balance between maximum and threshold contrasts in design. Designing on the edge of only noticeable differences (JND), or over-designing, is not a good idea. Visual perceptions vary greatly depending on the viewers and viewing conditions.
Contour and Luminance. Contrast is most affected by Luminance. Luminance refers to the reflection or emission visible light onto a surface. Also, it is used to measure perceived brightness (although they are not always the same thing in practice). Humans are therefore more sensitive for luminance due to the greater number light-processing and processing rods in their retinas. This luminance sensitivities allows people to adapt to various light conditions and detect changes easily.
Humans have developed the ability to detect changes in the environment throughout evolution through contour enhancements or variances on luminance levels. Edges can be created when the luminance of an object changes rapidly. This creates contrast between the stimulus’ background and it. Once an object is detected as having edges, its luminance changes rapidly, and the nerves in the eyes exaggerate it. This allows the visual cortex of the brain to process the object. This allows humans to identify objects in the environment and give them meaning or value based upon their appearance.
Hue and saturation. Hues allow us to distinguish between different spectral colors on the visible spectrum. The intensity of a hue’s dominant wavelength at saturation, also known as purity, is called the hue’s saturation. The purest hue, or the most saturated, is the one that has the greatest influence on the signal’s intensity and contrast. Unsaturated hues would, however, have “contributions to many other wavelengths” and a lower level of contrast. Avoiding heavily saturated hues is a good practice. People generally enjoy higher levels of saturation, but there are downsides to using high-saturated hues.
Motion and sizeMotion. The most important function in visual perception is the detection of motion. It has an impact on luminance, contrast, depth and luminance sensitive. The nerve endings within the retina’s peripheral are responsible for processing and calculating motion. “Motion” is the result of a change in the visual environment. It can help us understand how real-world stimuli are created and guide our behavior and actions. Motion is a design concept. Overuse can lead to over-stimulation. Humans cannot block out motion. Designers must strategically and intentionally use motion and movement to communicate meaning.
Size. Signal processing requires that the stimulus size be considered along with its luminance, contour and shape. The signal’s size has a direct correlation with its stimulus size. The signal strength increases with increasing stimulus size. Other factors that can influence and complicate size, such as distance from the stimulus, angle of view, and environmental conditions, can greatly affect its size. The relationship between size and viewing distance is inverted. As distance increases, perceived size becomes smaller. The opposite is true for size and viewing angles. The stimulus size grows as the viewing angle increases.
Design CaseEven though each concept of signal processing has been described in its own section, in reality they all interact with each other. We will analyze a real-world design example, which is Boston’s Citgo signage at night.
Brightness and Contours. Drivers will be able to see the signs’ boundaries by looking at the sharp edges. This stark contrast in luminance between the dark backdrop and sign makes it more noticeable. The red triangle has strong contrast to its white background because of its sharp edges and shape. Since our brains can detect contoured edges, we are able to perceive contrast by boosting the edges of the sign along with the triangle.
The LED lights inside the sign emit intense luminance at night. This is sending a strong signal through the visual cortex. The Citgo sign is visible from the driver’s view when they travel west on Storrow Drive. This can make it dangerous for their safety. Even in bad weather, the bright lights can blind or blur the vision temporarily, making it easier to get into accidents. It is not surprising that drivers could be distracted by the Citgo sign when driving, as they are most sensitive to changes in luminance.
Hue and saturation. The Citgo LED sign features high saturation and strong luminance. Citgo’s logo features the most intense colors, which are the dominant wavelengths of visible light. Saturation should be used sparingly in interface design. Too many colors can cause fatigue and eye strain. Red is generally very visible due to the many red-sensitive fovea cones. However, in low light situations it is difficult to see. While the retina is less sensitive than the red one, the human’s eye shifts towards the blue side of a color spectrum when low illumination levels are high. This gives it the appearance that it has higher luminance values. While both blue and red hues can be found at the visible spectrum, it is not a good design choice to place them close together, especially when they are full saturated. Red hues are most likely to push into the stimulus’s foreground while blue tends to fade into the background. The close proximity of the lights to the eyes creates a quivering effect similar to motion at the periphery. Citgo signs already use motion through high contrast, flashing patterns. But the added distraction of saturated hues is only going to make it more distracting.
Size. Because the sign, which measures sixty feet tall, can be seen from most parts of Boston, it is easily visible from the skyline above all the buildings. It is visible from the westbound traffic on Storrow Drive because of its size. At night, the sign’s stark contrast with the sky and buildings around it makes it stand out more than the rest. The sign’s strong contrast makes it visible from any distance. This can make driving dangerous as high contrast can lead to fatigue and eye movement, especially when driving. LEDs that have higher levels of saturation and luminance tend to have a quicker onset time than other light sources.
Design Recommendations The Citgo sign’s strong contrast can cause dangerous driving conditions, especially for night-time drivers. The sensory system will become fatigued if there are too many strong signals. Interaction designers should strive to find the optimal contrast when designing interfaces. One option is to use split complement theory to reduce saturation in Citgo’s blue and red hues. Mixing darker colors with the existing blue and red can help to reduce their intensity. The signal strength sent to passersby will be reduced by reducing the luminance, especially nighttime. This can reduce brightness perception and lessen the glare produced by bright lights. The suggested contrast changes will result in a predictable and more controlled outcome.
Conclusion: Vision is the way humans perceive and process their environment. It involves how light enters our eyes. Designers will be better able to understand signals and noise. This knowledge will help them to influence the behavior and psychology of signal processing. Designers want predictable outcomes. This is possible by applying psychological and perceptual concepts related to signal strength, contrast and other factors. Each factor has a unique role in determining contrast and signal strength. But it’s important to know how all these concepts impact visual perception, design, and overall perception. The combination of all these factors can have a negative effect on the eye, as demonstrated by the iconic Citgo sign in Boston. A designer will become more efficient if they are able to understand the role of each factor. Designers can make design more appealing and less burdensome by understanding each factor.
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