| 摘要 |
A video image creation system has means (22, 24, 26, 28) for storing image data at a first resolution. Means (54) for writing data into selected pixels of the storage means are provided and these may be under the control of a manually operable means. A display means (88) has a second lower resolution and each pixel in the display means displays an image portion derived from a group of pixels in the storage means. If the system is to simulate drawing with artists implements, the implement is represented by a group of pixels at a third higher resolution than the stored image. If the implement is to be written into the storage means at a particular location the stored image is enlarged to the same resolution as the implement, image data in the enlarged portion is replaced with image data derived from the pixels in the group, and image data for pixels in the stored image is derived from groups of pixels in the enlarged portion. An airbrush can be simulated by assigning a probability density function to a group of pixels representing the airbrush, positioning the group over a desired portion of the stored image and generating a random number for each pixel in the group. The random number is compared with the probability density function value for each pixel and new data written to that pixel in accordance with the result of the comparison. Another airbrush may be simulated by selecting a coordinate location where the airbrush is to be applied, randomly selecting a displacement from that location and then writing new image data to a pixel at that displacement. |
