Shape Coding Research Articles

New geometrical shape code and its optical recognition scheme

In this work, a symbolic code based on geometrical shapes is developed. The code can be used for both alphabet and phoneme of a particular language. The design of an optical scanner for reading the code is also presented. The code is applied to both the English and Arabic languages to demonstrate its use.

A shape coding array

An architecture designed for fast serial coding of object shapes is described. It consists of two mutually perpendicular arrays of bidirectional shift registers that are used, respectively, for horizontal and vertical image shifting. Parallel exchange of image data between the two nets is also possible. Shape coding operations are applied by a circular set of cells in one of the arrays, having distinguished parallel-out terminals.

Categorical shape and color coding by pigeons.

Categorical coding is the tendency to respond similarly to discriminated stimuli. Past research indicates that pigeons can categorize colors according to at least three spectral regions. Two present experiments assessed the categorical coding of shapes and the existence of a higher order color category (all colors). Pigeons were trained on two independent tasks (matching-to-sample, and oddity-from-sample). One task involved red and a plus sign, the other a circle and green. On test trials one of the two comparison stimuli from one task was replaced by one of the stimuli from the other task. Differential performance based on which of the two stimuli from the other task was introduced suggested categorical coding rules. In Experiment 1 evidence for the categorical coding of sample shapes was found. Categorical color coding was also found; however, it was the comparison stimuli rather than the samples that were categorically coded. Experiment 2 replicated the categorical shape sample effect and ruled out the possibility that the particular colors used were responsible for the categorical coding of comparison stimuli. Overall, the results indicate that pigeons can develop categorical rules involving shapes and colors and that the color categories can be hierarchical.

Categorical shape and color coding by pigeons.

Categorical coding is the tendency to respond similarly to discriminated stimuli. Past research indicates that pigeons can categorize colors according to at least three spectral regions. Two present experiments assessed the categorical coding of shapes and the existence of a higher order color category (all colors). Pigeons were trained on two independent tasks (matching-to-sample, and oddity-from-sample). One task involved red and a plus sign, the other a circle and green. On test trials one of the two comparison stimuli from one task was replaced by one of the stimuli from the other task. Differential performance based on which of the two stimuli from the other task was introduced suggested categorical coding rules. In Experiment 1 evidence for the categorical coding of sample shapes was found. Categorical color coding was also found; however, it was the comparison stimuli rather than the samples that were categorically coded. Experiment 2 replicated the categorical shape sample effect and ruled out the possibility that the particular colors used were responsible for the categorical coding of comparison stimuli. Overall, the results indicate that pigeons can develop categorical rules involving shapes and colors and that the color categories can be hierarchical.

A natural approach in image processing and pattern recognition: Rotating neighbourhood technique, self-adapting threshold, segmentation and shape recognition

Sentence description of objects are utilized in the model. The description is transformable into graphs. Fast shape coding is accomplished by an operator translated along linear objects or contours. A separate node of a graph is obtained for each new position of the operator. After a reduction, the graph is equivalent to a sentence describing an object. A technique incorporating a rotating neighbourhood is introduced and utilized for image enhancement and texture derivation. The technique preserves edges of objects. A threshold which adapts itself to an unknown noise level and image segmentation into individual objects are also presented. All the methods discussed satisfy the basic condition on representing images.

The Influence of a Fixed Background in a VDU Display on the Efficiency of Colour and Shape Coding

Few studies investigating the merits of colour coding use displays where a fixed background picture increases the predictability of the number or location of the signals. In this study the effects of type of task, coding and display format on the use of VDU-presented information are examined. Two types of tasks were used: a search task and an identification task. There were three coding conditions: shape, colour and colour/shape coding. Information could be displayed in fixed and free format. In fixed format displays the coded information was presented as measuring points in flow schemes of a crude oil distilling plant. In the free format displays this background picture was not presented. The results show that the background pattern decreases search performance under all coding conditions. Search with shape coding is inferior to that with colour and colour/shape coding. Identification task performance is slightly better with shape coding. The results suggest, that in the search task the background pattern inhibits efficient scanning of the display.

Strategy choices by young Braille readers.

The hypotheses that in Braille learning coding strategies change with reading level, and coding differs between normal and retarded readers were tested with oddity judgments by blind children. Experiment 1 showed that strategy choices varied with reading level only in association with mental age. By contrast, shape neglect and preference for phonological strategies were shown by retarded readers rather than by matched normal readers. Experiment 2 showed that under instructions to use given coding strategies the retarded were as accurate as normal readers. Accuracy for all forms of coding increased with reading level, but coding word shape was significantly less accurate than other forms of coding, and even correct coding of shape was no faster than semantic or phonological coding. It is concluded that coding the shape of Braille words is unlikely to be a major factor in producing faster Braille reading, and retarded Braille readers differ from normal readers in their spontaneous choice of strategy rather than in the ability to use the relevant codes.

The Effect of Redundant Cues on Retrieval Time

This experiment was concerned with determining the effect of redundant shape and color cues on retrieval time. Subjects saw a pair of stimuli presented sequentially on a screen and pressed one of two keys to indicate whether the second stimulus was the same as or different from the first. Stimuli for the color coding group differed only in terms of color (i.e., red, green, or yellow). Stimuli for the shape coding group differed only in terms of shape (i.e., circles, squares, or triangles). Stimuli for the redundant coding group were red, green, or yellow circles, squares, or triangles, with each shape having its own distinctive color. There was no clear-cut evidence that redundant coding facilitated retrieval of information from short-term memory. The redundant coding group (409 ms) was significantly faster than the color coding group (540 ms), but was not significantly faster than the shape coding group (456 ms). The difference between the shape and color coding groups was not significant. Same responses were significantly faster than different responses (449 versus 487 ms).

Communication effectiveness of symbolic safety signs with different user groups

Contrary to popular belief, little systematic evaluation has been undertaken of how well public information signs convey their intended message. The application of a proposed evaluation procedure, involving an initial Recognition Test and a subsequent Recall Test, to a set of occupational safety signs is reported. Respondents comprised migrants and native-born Australian attending adult literacy classes, including a group of recently-arrived Vietnamese. Despite inter-group differences in the total number of signs correctly identified on both Recognition and Recall Tests, the same signs gave rise to difficulty for all groups. The sources of difficulty are discussed in terms of distinctiveness of referents, comprehension of shape and colour code, and translation from symbol to referent. The implications of the test results for user education programmes is also considered.

The Effects of Shape Coding and Mirror Imaging of Control Knobs

On machines that have two operator workstations, there is sometimes a question of the optimum arrangement of controls. The controls at both workstations can be either mirror imaged or arranged in a left-to-right sequence. This experiment was performed to investigate the sequential arrangement of controls on a dual workstation roof bolter, a machine used in underground coal mining. The use of shape coded control knobs was also investigated to determine their relative advantage with each arrangement. The results indicated that there was no clear stereotype for the arrangement of controls. Shape coded knobs were somewhat helpful during learning.

Safety labelling of consumer products: Shape and colour code stereotypes in the design of signs : TRC Repost No T79-8008; University of Aston, Applied Psychology Department, Birmingham, Report No AP-REP-75, Dec 1977, 49 pp, abstr in: R and D Abstracts

Safety labelling of consumer products: Shape and colour code stereotypes in the design of signs : TRC Repost No T79-8008; University of Aston, Applied Psychology Department, Birmingham, Report No AP-REP-75, Dec 1977, 49 pp, abstr in: R and D Abstracts

Adaptive noise spectral shaping and entropy coding in predictive coding of speech

We report on research to code speech at 16 kbit/s with the goal of having the quality of the coded speech be equal to that of the original. Some of the original speech had been corrupted by noise and distortions typical of long-distance telephone lines. The basic structure chosen for our system was adaptive predictive coding. However, the rigorous requirements of this work led to a new outlook on the different aspects of adaptive predictive coding. We have found that the pitch predictor is not cost-effective on balance and may be eliminated. Solutions are presented to deal with the two types of quantization noise: clipping and granular noise. The clipping problem is completely eliminated by allowing the number of quantizer levels to increase indefinitely. An appropriate self-synchronizing variable-length code is proposed to minimize the average data rate; the coding scheme seems to be adequate for all speech and all conditions tested. The granular noise problem is treated by modifying the predictive coding system in a novel manner to include an adaptive noise spectral shaping filter. A design for such a filter is proposed that effectively eliminates the perception of granular noise.

Confusions in memory for tactile presentations of letters

This investigation explored the possibility of a tactile as well as acoustic component for short-term memory by tactilely presenting groups of letters on subjects’ backs. Letters varied in phonetic similarity and spatial location. Recall error rates were assessed according to Wickelgren’s (1965) ordered, item, and position recall criteria. Spatial location showed no effect. High phonetic similarity produced more errors than low phonetic similarity by ordered and position recall criteria. This effect was attributed to translation to acoustic representations for storage in short-term memory. The results suggest that shape coding may also function along with acoustic coding as an additional strategy for aiding recall of tactilely presented letter sequences.

Ballistic limit determination in impacts on multimaterial laminated targets

Two-dimensional numerical analyses have been performed of projectile impacts at 15,00020,000 fps into finite laminated targets consisting of plastic layers backed by aluminum substrates. These analyses used the SHAPE code, with a hydrodynamic-elastic-plastic distortional model. Three solutions are discussed. The first illustrates phenomena occurring during impacts just under the perforation threshold. Results showing the time-resolved development of rear surface bulging are compared with dynamic observations of parallel experiments. Good agreement is obtained. The second and third solutions show conditions leading to perforation. Using a generalized plastic strain criterion, two failure modes are identified. Petalling tends to occur where the plastic front layer of the target is relatively thick and the failure criterion is first exceeded on the back surface near the axis. Plugging occurs in thinner targets when the failure criterion is first exceeded at an off-axis location on the plastic-substrate interface. Through use of SHAPE and this failure criterion, predictions can be made as to whether a given impact will perforate a given multilayered target.

RECEPTIVE FIELDS AND FUNCTIONAL ARCHITECTURE IN TWO NONSTRIATE VISUAL AREAS (18 AND 19) OF THE CAT.

RECEPTIVE FIELDS AND FUNCTIONAL ARCHITECTURE IN TWO NONSTRIATE VISUAL AREAS (18 AND 19) OF THE CAT.

Anomalous transfer effects after shape discrimination training in the rat

Krechevsky has observed an anomalous transfer effect in rats which he explained by the Gestalt principle of proximity. The effect has been referred to by others more or less as a curiosity, but has not generated further research until now. The effect was replicated under tighter and more extensive conditions, and was found to apply to both positive and negative training shapes. The importance of these findings for behavioral analysis of shape and contour coding in the mammalian visual system is discussed.

Color versus shape coding in information displays.

Color versus shape coding in information displays.