669 research outputs found
Image enhancement with MatLab algorithms
No full textNowadays, a lot of applications use digital images. For example in face recognition to detect and tag persons in photograph, for security control, and a lot of applications that can be found in smart cities, as speed control in roads or highways and cameras in traffic lights to detect drivers ignoring red light. Also in medicine digital images are used, such as x-ray, scanners, etc. These applications depend on the quality of the image obtained. A good camera is expensive, and the image obtained depends also on external factor as light.
To make these applications work properly, image enhancement is as important as, for example, a good face detection algorithm. Image enhancement also can be used in normal photograph, for pictures done in bad light conditions, or just to improve the contrast of an image. There are some applications for smartphones that allow users apply filters or change the bright, colour or contrast on the pictures.
This project compares four different techniques to use in image enhancement. After applying one of these techniques to an image, it will use better the whole available dynamic range. Some of the algorithms are designed for grey scale images and others for colour images. It is used Matlab software to develop and present the final results. These algorithms are Successive Means Quantization Transform (SMQT), Histogram Equalization, using Matlab function and own implemented function, and V transform.
Finally, as conclusions, we can prove that Histogram equalization algorithm is the simplest of all, it has a wide variability of grey levels and it is not suitable for colour images. V transform algorithm is a good option for colour images. The algorithm is linear and requires low computational power. SMQT algorithm is non-linear, insensitive to gain and bias and it can extract structure of the data.
RESUMEN.
Hoy en día incontable número de aplicaciones usan imágenes digitales. Por ejemplo, para el control de la seguridad se usa el reconocimiento de rostros para detectar y etiquetar personas en fotografías o vídeos, para distintos usos de las ciudades inteligentes, como control de velocidad en carreteras o autopistas, cámaras en los semáforos para detectar a conductores haciendo caso omiso de un semáforo en rojo, etc. También en la medicina se utilizan imágenes digitales, como por ejemplo, rayos X, escáneres, etc. Todas estas aplicaciones dependen de la calidad de la imagen obtenida. Una buena cámara es cara, y la imagen obtenida depende también de factores externos como la luz.
Para hacer que estas aplicaciones funciones correctamente, el tratamiento de imagen es tan importante como, por ejemplo, un buen algoritmo de detección de rostros. La mejora de la imagen también se puede utilizar en la fotografía no profesional o de consumo, para las fotos realizadas en malas condiciones de luz, o simplemente para mejorar el contraste de una imagen. Existen aplicaciones para teléfonos móviles que permiten a los usuarios aplicar filtros y cambiar el brillo, el color o el contraste en las imágenes.
Este proyecto compara cuatro técnicas diferentes para utilizar el tratamiento de imagen. Se utiliza la herramienta de software matemático Matlab para desarrollar y presentar los resultados finales. Estos algoritmos son Successive Means Quantization Transform (SMQT), Ecualización del histograma, usando la propia función de Matlab y una nueva función que se desarrolla en este proyecto y, por último, una función de transformada V.
Finalmente, como conclusión, podemos comprobar que el algoritmo de Ecualización del histograma es el más simple de todos, tiene una amplia variabilidad de niveles de gris y no es adecuado para imágenes en color. El algoritmo de transformada V es una buena opción para imágenes en color, es lineal y requiere baja potencia de cálculo. El algoritmo SMQT no es lineal, insensible a la ganancia y polarización y, gracias a él, se puede extraer la estructura de los datos
Combining Keynes and Schumpeter. Ingvar Svennilson's Contribution to the Swedish Growth School and Modern Economics
No full textIn a study of European growth in the interwar period, the Swedish economist Ingvar Svennilson integrated a Keynesian theory of cumulative growth with a Schumpeterian analysis of economic transformation. Svennilson emphasised that innovations and the use of new technologies had been stimulated by high demand and production growth. Svennilson’s strong commitment to "Vendoorn's Law" which actually was "Svennilson's Law", made it difficult to incorporate him in a Schumpeterian tradition. A synthesis between Keynes and Schumpeter with Svennilson as a mediator was also prevented by the decisive role of entrepreneurship and the critique of Keynesian models in works by Schumpeter and the Swedish growth school. However, a synthesis has been facilitated by neo-Schumpeterian theories of demand-led innovations and cumulative economic processes. Svennilson’s study has been superseded by later contributions to economics except for a theory of a negative, "Keynesian", relationship between unemployment and growth and an exceptional "un-Verdoornian" theory that high aggregate demand may lead to crowding-out of new firms from capital markets. Besides, Svennilson's integration of short run and long run macro analysis and of theoretical and empirical work is still a fruitful research strategy in economics.Innovations; Cumulative Growth; Productivity Growth; Verdoorn’s Law; Swedish Growth School
«Det absurde ved å være fanget i blodbankende materie»: Om rus og litteratur i Ingvar Ambjørnsens \u27Skogens hjerte\u27
No full textThis article explores Norwegian author Ingvar Ambjørnsen’s short story «The Heart of the Forest» from his collection Dark Dawn (1997) and focuses on the story’s prime experience, that of drugs. Peter Sloterdijk’s account of the historical development of drugs from the early Greek era to modernity is the theoretical framework. His understanding is found in Ambjørnsen’s short text, which also contains a notion of intertextuality. Therefore, the article highlights both literary (Vesaas) and philosophical references (Huxley). «The Heart of the Forest» is also the precursor for Ambjørnsen’s novel The Night Dreaming of Day (2012), which implies that the author sampled his own short story and gave it a pessimistic reinterpretation.Artikkelen undersøker Ingvar Ambjørnsens novelle «Skogens hjerte» fra novellesamlingen Natt til mørk morgen (1997) og fokuserer på fremstillingen av ruserfaringer som står sentralt i teksten. Utgangspunktet for lesningen er Peter Sloterdijks beskrivelse av den historiske utviklingen av ruserfaringer fra antikken til det moderne. Hans forståelse finner man også i Ambjørnsens korttekst, men denne omfatter dessuten en bestemt bruk av intertekstualitet. Herved fokuseres det både på litterære (f.eks. Vesaas) og idéhistoriske referanser (Huxley). «Skogens hjerte» ble i tillegg det intertekstuelle forelegget for deler av Ambjørnsens roman Natten drømmer om dagen (2012). På en måte ‘sampler’ forfatteren sin egen novelle, som får en mer pessimistisk omfortolking
FFT i ett historiskt perspektiv [Elektronisk resurs]
No full textNågra nedslag i Fouriertransformens historia och FFT:ns ursprung från 1805 och framåt behandlas i denna populära betraktelse. Vi stannar upp ett slag hos Gauss, funderar över vad han gjort för oss ingenjörer och vi avslutar med en del praktiska konsekvenser och tips som är aktuella idag.</p
FFT i ett historiskt perspektiv
No full textNågra nedslag i Fouriertransformens historia och FFT:ns ursprung från 1805 och framåt behandlas i denna populära betraktelse. Vi stannar upp ett slag hos Gauss, funderar över vad han gjort för oss ingenjörer och vi avslutar med en del praktiska konsekvenser och tips som är aktuella idag
Active Noise Control in Propeller Aircraft
No full textA noisy environment dominated by low frequency noise can often be improved
through the use of active noise control. This situation arises naturally in
propeller aircraft where the propellers induce periodic low frequency noise
inside the cabin. The cabin noise is typically rather high, and the passenger
flight comfort could be improved considerably if this level were significantly
reduced. This paper addresses same design aspects for multiple-reference active
noise control systems based on the feedforward strategy. The paper also
discusses the operation of narrowband feedforward active noise control system
and presents results from experiments
A Method for Reduced Finite Precision Effects in Parallel Filtering Echo Cancellation
No full textThe two-path algorithm is an adaptive filter algorithm based on a parallel filter structure, which has been found to be useful for line echo cancellation as well as for acoustic echo cancellation. It is well known that in finite precision arithmetic, the adaptation process of adaptive algorithms can be reduced or even halted due to finite precision effects. This paper proposes a variant of the two-path scheme where the effects of quantization are reduced, without any significant increase in complexity. The improvement is shown by simulations using bandlimited flat spectrum noise as well as real speech signals
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