Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for enveloping a thread of execution within an IDT-based secure sandbox. In one aspect, embodiments of the invention provide a method performed in a computer system, the method receiving an instruction from an execution thread where the computer system can be configured for redirection of instructions from the execution thread. The method can determine whether the instruction includes at least one of an interrupt instruction, a system call instruction and a system enter instruction. In response to determining that the instruction includes at least one of the interrupt instruction, the system call instruction and the system enter instruction, the method can further: (i) eliminate the redirection, (ii) modify a stack to specify return of control, and (iii) thereafter, pass the control to an operating system kernel.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for enveloping a thread of execution within an IDT-based secure sandbox. In one aspect, embodiments of the invention provide a method performed in a computer system, the method receiving an instruction from an execution thread where the computer system can be configured for redirection of instructions from the execution thread. The method can determine whether the instruction includes at least one of an interrupt instruction, a system call instruction and a system enter instruction. In response to determining that the instruction includes at least one of the interrupt instruction, the system call instruction and the system enter instruction, the method can further: (i) eliminate the redirection, (ii) modify a stack to specify return of control, and (iii) thereafter, pass the control to an operating system kernel.

Abstract: A method and computer program for approximating a gradient, the gradient defining a nonlinear transition from one color or gray level to another in an image where the rate of transition is determined by the function y=xe where e>1. The method includes identifying an error tolerance, selecting an optimal number of set points on a curve defined by the function including determining each set point by evaluating a maximum error between a line defined by a pair of set points and a corresponding portion of the curve using the error tolerance and approximating the curve by a series of linear portions connecting the set points.

Abstract: A method and computer program for approximating a gradient, the gradient defining a nonlinear transition from one color or gray level to another in an image where the rate of transition is determined by the function y=xe where e>1. The method includes identifying an error tolerance, selecting an optimal number of set points on a curve defined by the function including determining each set point by evaluating a maximum error between a line defined by a pair of set points and a corresponding portion of the curve using the error tolerance and approximating the curve by a series of linear portions connecting the set points.