Sammanhang. Genom att använda steganografi i bilder är det möjligt att lagra en stor mängd data utan att påverka bilden som information lagras i. En vanlig metod som används inom steganografi är LSB (Least Significant Bit), som ofta anses vara en av de första metoderna som användes inom steganografi. Förutom valet av metod har personen ett val att göra när hen ska välja en bild som ska representera bärare av information. Vad man ofta försöker åstadkomma är att skapa en komplex metod men glömmer bort bilden som ska användas som bärare. I slutändan är det bilden som kommer att användas och testas vid olika mätningar. Mål. Den här studien kommer att undersöka om olika typer av bildformat, BMP, PNG, JPEG och TIFF, har någon påverkan när jämförelse görs av originalbilden och den modifierade, givet att en steganografisk metod används för att lagra informationen. Studien kommer även att undersöka om bildrepresentationen har någon påverkan på mätningarna. Metod. En utbyggd metod av Least Significant Bit metoden kommer att implementeras och användas för att lagra information i olika typer av bilder med olika bildformat. Ett experiment sätts upp för att undersöka formaten med hjälp av mätningsverktygen MSE (Mean Squared Error), PSNR (Peek Signal-to-Noise Ratio) och SSIM (Structural Similarity). Resultat. Vid jämförelse av de grafer och tabeller som togs fram, sågs JPEG ha ett bättre resultat genom att ha ett lägre differentiellt värde mellan varje test. BMP, PNG och TIFF hade minimala skillnader mellan varandra för varje test. För bildrepresentationen visade två bilder högre differentiellt värde än de resterande tre. Sammanfattning. Resultaten från experimentet visade att vilken komprimeringsmetod som ett bildformat använder kommer ha påverkan på mätningsvärdena. Resultaten visade också att bildrepresentation kan ha en påverkan på mätningarna av en bild men mer data behövs för att dra en slutsats. / Context. By using image steganography it is possible to hide a large amount of data without making big differences to the initial picture. One commonly used method is Least Significant Bit (LSB), which often is considered one of the first method implemented and used in Image Steganography. Apart from the method, the user also have a choice when deciding what picture he or she should use as the carrier of information. What people often try to accomplish is to have a very complex method that hides the data in an efficient way, but forgets about the picture used as a carrier. In the end, all measurements will be done on the picture. Objectives. This study will investigate if different image formats, BMP, PNG, JPEG and TIFF, have an impact on the differences when comparing the original picture with the modified, given that data is stored with a steganographic method and is gradually increased. The study will also investigate if what the picture visually represent will have an effect on the measurements. Methods. An extended method of the Least Significant Bit method will be implemented and used to create different pictures with different kinds of image formats. An experiment will investigate these formats by taking measurements with MSE (Mean Squared Error), PSNR (Peek Signal-to-Noise Ratio) and SSIM (Structural Similarity). Results. When comparing different formats one could say that JPEG showed better performance by having a lower differential value between each test, by looking at the graphs and tables. BMP, PNG and TIFF had minimal changes between each other for each test. As for the visual representation of the pictures, two pictures showed a higher differential value after each test than the remaining three. Conclusions. The results from the experiment showed that which compression method a format uses will have an impact on the measurement. The results also showed that the pictures’ visual representation could have some impact on the measurement of a picture but more data is needed to conclude this theory.

High-speed laser triangulation 3D cameras, such as the Ranger3 from SICK, transmit image data to a PC for processing. The camera’s operational speed is constrained by the capabilities of the transmission link. By compressing the data, the bandwidth requirements of the camera is reduced. This thesis presents the development of a lossless image compression format developed for this purpose. The proposed image compression format features a single-pass encoder that utilizes run-length and delta encoding. It is designed to be suitable for implementation on field-programmable gate arrays (FPGAs) within high-speed laser-scanning cameras. Furthermore, the format offers configurability through parameters, enabling optimization for diverse types of image data to achieve more efficient compression. The compression ratio of the image compression format was evaluated using a range oftypical images captured by a Ranger3 camera. The compression ratio was measured across different configurations of the format and subsequently compared with that of PNG. The compression ratio achieved by the proposed format is on par with that of the PNG format, despite having a much simpler encoding process.

This research aims to examine a framework to test the relationships between consumers' perceptions of a retailer's brand personality and outcome variables (i.e., positive word-of-mouth about and patronage intention toward the retailer) by applying identity and social identity theories to reveal possible factors influencing these relationships in both department and discount retailer image formats. This research hypothesized that retailer brand personality should influence consumers' behavioral outcomes through private and public forms of self-congruity. The more positive the perception of a retailer's brand personality, the higher the private and public self-congruities with the brand personality. In addition, considering the unique, tangible nature of a store's environment, this research suggested that retailer brand identity (RBI), a consumer's perception of oneness with a retailer brand, should play an important role in the retailer brand personality-behavioral outcomes framework by mediating the influences of both private and public self-congruities on various behavioral outcomes. Moreover, the relationships among two forms of self-congruity and perceived RBI should be moderated by the shopping conspicuousness situation (i.e., whether co-shopping with important others or alone and whether shopping in an environment in which one is visible to important others or is relatively secluded) and consumer shopping involvement (i.e., whether consumers see shopping as an important and self-relevant activity). To test the study's hypotheses, data were collected from a sample of 616 general consumers via a self-administered questionnaire provided through the website of an online survey research firm. This research used a 2 (retailer image format) X 2 (shopping situation conspicuousness) between-subjects quasi-experimental design in which subjects were randomly assigned to one of the four treatment groups who read a scenario that provided a description of a retailer image format of either a hypothetical department (n = 311) or discount store (n = 305) and a description that manipulated the shopping situation as being either high (n = 303) or low (n = 313) in shopping conspicuousness. Results revealed that the retailer brand personality scale, adapted from BPS, a brand personality scale developed by Aaker (1997) and other scales specifically used to measure retailer brand personality (Dardin & Babin, 1994; d'Astous & Lévesque, 2003; Helgeson & Supphellen, 2004) comprised two positive dimensions (i.e., Modish and Genuine) and one negative dimension (Inactive). Each dimension influenced the behavioral outcomes of Word-of-Mouth and Patronage Intention differently. Perceived Genuineness was the most influential dimension among the three, exerting direct and indirect influences through increasing Private and Public Self-congruities and overall RBI on both WOM and Patronage Intention. However, Modish had only a direct negative effect on Patronage Intentions whereas Inactive had indirect effects on both behavioral outcomes through a combined (direct and indirect) negative effect on overall RBI. This research also revealed that overall RBI, driven by its affective and evaluative dimensions, fully mediated the influences of Private and Public Self-congruities on behavioral outcomes, suggesting overall RBI as an important factor in the retailer brand personality-behavioral outcomes framework. Moreover, the relationship between Public Self-congruity and overall RBI was found to be stronger in the high Shopping Conspicuousness Situation whereas the relationship between Private Self-congruity and overall RBI was found to be stronger in the department store image format. The moderating role of Consumer Shopping Involvement on the relationships among self-congruities and overall RBI was not significant. Theoretical and managerial implications of these findings and limitations of the study are provided.

The process of contourization is presented which converts a raster image into a discrete set of plateaux or contours. These contours can be grouped into a hierarchical structure, defining total spatial inclusion, called a contour tree. A contour coder has been developed which fully describes these contours in a compact and efficient manner and is the basis for an image compression method. Simplification of the contour tree has been undertaken by merging contour tree nodes thus lowering the contour tree's entropy. This can be exploited by the contour coder to increase the image compression ratio. By applying general and simple rules derived from physiological experiments on the human vision system, lossy image compression can be achieved which minimises noticeable artifacts in the simplified image. The contour merging technique offers a complementary lossy compression system to the QDCT (Quantised Discrete Cosine Transform). The artifacts introduced by the two methods are very different; QDCT produces a general blurring and adds extra highlights in the form of overshoots, whereas contour merging sharpens edges, reduces highlights and introduces a degree of false contouring. A format based on the contourization technique which caters for most image types is defined, called the contour tree image format. Image operations directly on this compressed format have been studied which for certain manipulations can offer significant operational speed increases over using a standard raster image format. A couple of examples of operations specific to the contour tree format are presented showing some of the features of the new format.