Smart painting tools

A system for automatically computing tool properties of a virtual paint brush, comprising:

• a platform that includes hardware and software resources that connects over a network to at least one computing device remote from the platform,
• wherein the platform is configured to:
• receive a brush stroke of the virtual paint brush at a point on a digital image from the network;
• find an object boundary in the digital image that corresponds to the point of the brush stroke by marking the point that received the brush stroke as a base region and scanning a region that surrounds the base region;
• compute a tangential slope of the object boundary at the point of the brush stroke;
• adjust tool properties of the virtual paint brush based on a change of the tangential slope of the object boundary;
• transmit data representing the digital image and the adjusted tool properties of the virtual paint brush over the network to the at least one computing device;
• and
• repeat said steps of computing a tangential slope and adjusting tool properties when a new brush stroke of the virtual paint brush is received from the network.

A method of automatically computing tool properties of a virtual paint brush, the method comprising:

• receiving a brush stroke of the virtual paint brush from a user at a point, and finding an object boundary that corresponds to the point of the brush stroke;
• computing a tangential slope of the object boundary at the point of the brush stroke;
• and
• computing tool properties of the virtual paint brush based on changes in the object boundaries, wherein tool properties of the virtual paint brush include a brush tip size and a brush tip rotation angle,
• wherein automatically computing the brush tip size comprises finding a maximum enclosing rectangle at a point when the user has performed a mouse down event, wherein the maximum enclosing rectangle is that which can fit object boundaries that surround the point, wherein dimensions of the maximum enclosing rectangle are in a same aspect ratio as a preset pattern chosen by the user, wherein a size of the maximum enclosing rectangle is adjusted by a predetermined number of pixels when the pattern mask extends beyond an object boundary, and
• wherein automatically computing the brush tip rotation angle comprises computing a difference of a current tangential slope with respect to a previous tangential slope, and rotating a brush tip as the difference is computed by an amount that corresponds to the difference.