Image data format conversion apparatus with interpolation filters

摘要

An image data format conversion apparatus comprises: a memory storing image data; a data reading means reading image data from the memory to output it; a format converting means converting the image data output from the data reading means to a predetermined format to output it or making the image data pass through without converting it; a vertical filter vertically interpolating the image data output from the format converting means by filtering operation to output the data or making the image data pass through without interpolating it; a horizontal filter vertically interpolating the image data output from the vertical filter by filtering operation to output the data or making the image data pass through without interpolating it; an image synthesizing means performing logic operation for image data output from the filter, and synthesizing the image data to output it; and an image output means outputting the image data from the image synthesizing means to a designated display unit. In this image data format conversion apparatus, as a memory for storing groups of image data with different formats (attributes) is provided, and after making uniform the format of the image data output from the memory, interpolating processing is performed using the vertical and horizontal filters to reduce flickers. Furthermore, since image reducing/expanding processing is performed utilizing the interpolating processing to make pixel ratios uniform and then operations are performed for plural series of image data to synthesize plural series of images with a same ratio in the image synthesizing means, it is possible to implement filters and buffers necessary to make uniform formats when plural series of original images having different formats are superposed and displayed, making use of filters and buffers used for flicker reducing processing, and thus hardware cost can be minimized. In addition, in the image data format conversion apparatus, the image data obtained by synthesization in the image synthesizing means is not output directly to the display, instead the data is once written into the memory to be synthesized with the other original image. Therefore, it is not necessary to consider a correspondence between a production rate of moving picture data and a display rate of the display unit, whereby system configuration is facilitated.