Fusion of SPOT5 multispectral and Ikonos panchromatic images

International audienceThe offer of high spectral and high spatial resolutions images has grown in the last decade. It is know possible to obtain data from different sources with different spatial and spec-tral resolutions. The field of data fusion of remotely sensed data grown also very fast in the last years. In this paper, an algorithm allowing the merging of SPOT 5 images and Ikonos images are proposed. This algorithm is based on the ARSIS concept and presents an implementation for a ratio of spatial resolution equal to 10. The ARSIS concept is first detailed. Then, the way of de-fining a new implementation based on this concept is presented, allowing to understand how to define new implementations and to develop new solutions based on this concept. The proposed algorithm is developed, describing the different steps for building a fused product from a SPOT 5 multispectral data at 10 m and from a IKONOS panchromatic data at 1 m. Some other methods are proposed. The evaluation of the quality of the different methods is achieved using a set of quantitative quality parameters. The visual quality of the products are evaluated by a set of inter-preters. Conclusions are drawn on the quality of the proposed products

Satellite imagery fusion with an equalized trade-off between spectral and spatial quality

En este trabajo se propone una estrategia para obtener imágenes fusionadas con calidad espacial y espectral equilibradas. Esta estrategia está basada en una representación conjunta MultiDirección-MultiRresolución (MDMR), definida a partir de un banco de filtros direccional de paso bajo, complementada con una metodología de búsqueda orientada de los valores de los parámetros de diseño de este banco de filtros. La metodología de búsqueda es de carácter estocástico y optimiza una función objetivo asociada a la medida de la calidad espacial y espectral de la imagen fusionada. Los resultados obtenidos, muestran que un número pequeño de iteraciones del algoritmo de búsqueda propuesto, proporciona valores de los parámetros del banco de filtro que permiten obtener imágenes fusionadas con una calidad espectral superior a la de otros métodos investigados, manteniendo su calidad espacial

Image Fusion - The ARSIS concept and some successful implementation schemes

International audienceThis article aims at explaining the ARSIS concept. By fusing two sets of images A and B, one with a high spatial resolution, the other with a low spatial resolution and different spectral bands, the ARSIS concept permits to synthesise the dataset B at the resolution of A that is as close as possible to reality. It is based on the assumption that the missing information is linked to the high frequencies in the sets A and B. It searches a relationship between the high frequencies in the multispectral set B and the set A and models this relationship. The general problem for the synthesis is presented first. The general properties of the fused product are given. Then, the ARSIS concept is discussed. The general scheme for the implementation of a method belonging to this concept is presented. Then, this article intends to help practitioners and researchers to better understand this concept through practical details about implementations. Two Multi-Scale Models are described as well as two Inter-Band Structure Models. They are applied to an Ikonos image as an illustration case. The fused products are assessed by the means of a known protocol comprising a series of qualitative and quantitative tests. The products are found of satisfactory quality. This case illustrates the differences existing between the various models, their advantages and limits. Tracks for future improvements are discussed

The ARSIS concept in image fusion: an answer to users needs

International audienceThe ARSIS concept (from its French name "amélioration de la résolution spatiale par injection de structures" that means improvement of the spatial resolution by structure injection) is briefly presented. It offers a framework for the synthesis of multi-modality images at highest spatial resolution by fusion of two sets of images. This concept is comprised of three types of models. These different types are introduced and a set of solutions for implementation proposed. Four solutions are detailed and applied to a satellite Ikonos image of the city of Hasselt, Belgium. The fusion products are analyzed visually and quantitatively. These analyses enhance the benefits of offering a set of solutions to remote sensing end-users in order to fulfill their needs

Different implementations of the ARSIS concept to fulfill users needs

International audienceThere is a need for synthetic products that simulate satellite multispectral data at a higher spatial resolution. The users needs are various and somehow opposite: needs of high spatial resolution for accurate geometrical description of objects and needs for high spectral resolution for accurate spectral content and subsequent classification process. The ARSIS concept (from its French name "amélioration de la résolution spatiale par injection de structures" that means improvement of the spatial resolution by structure injection) permits to construct such synthetic products by fusion of two sets of data, namely panchromatic images at high spatial resolution and multispectral images at lower spatial resolution. It offers a framework wherein different models can be combined to form different solutions to better satisfy the users needs. An example is given of an Ikonos image of the city of Hasselt, Belgium