Digital Dream Studio V2

Feature list

Basic Concepts

Selection

Blending modes

Effects

Step-by-step guide to DDS

• Constant color. This one is quite simple: it just applies the selected color over a designated surface, in accordance with the selection map, blending options and opacity.
• Gradient tool. The Gradient tool one may encouter in other design software is given a completly new dimension in DDS V2. Linear, circular and angular gradients are just the beginning. A practically infinite amount of other gradients, with complex shapes and variations can be defined. The gradients are actually values ranging from 0 to 1. Using linear interpolation, these values are linked to RGBAlpha values, and an interesting 32 bit bitmap surface is drawn.
• Texture. By texture, one may simply understand a RGB image. Thus texturizing, is applying the texture's color upon a designated surface, considering extrapolation methods, X,Y offsets and, of course, selection map, blending options and opacity. The Texture tool has a wide variety of applications. If one selects "Layer" as reference and "Auto" for automatic load of layer, the result is a classical cloning brush.
• Color correction involves the optimization of color space and visualization in an image, using effects as levels, gamma, contrast. Also, for rather unconventional effect the user can write his own equations for modifying the color space.
• Convolution generally refers to bluring, sharpening, edge detection and edge enhancement. There are two methods of convoluting in DDS and another one especially designed for fast gaussian blur.

  The first method involves convolution with a custom MxN matrix of real numbers. Two separate convolutions can be defined: one for RGB and another for the Alpha channel. Also, convolution can be applied only on RGB or only on the Alpha channel. The convolution matrixes can be defined by a function of two variables. Gaussian blur is defined by the Gauss surface (exp(0-a*hypot(x,y)); classical blur is defined by a constant value; one may also manually modify the convolution kernels.

  A much faster method, which is generally almost as efficient, is the convolution with a kernel of constant size (3x3) and integer coefficients. Also, convolutions may be applied separatelly on RGB and Alpha. There are predefined kernels (Laplace operator, blurring, sharpening etc). The user may also manually modify kernels.

  The (non-linear) Gaussian blur is very fast compared to the MxN method, because it performs integer and bitwise specialized operations. The user must specify only the radius of the blur - everything else is set up automatically.

  The general options allow the user to specify whether the effect is applied on the entire layer or exclusively on the selected surface. Also, the use of blending equations is optional.

  The extrapolation of opacity is crucial, especially for gaussian blur. The boundary method maps pixels on the boundary region of the surface, while constant method considers the outer pixels as being of constant values.

  In the V2 version of DDS, several fast methods of blurring have been included: Linear Blur, True Gaussian Blur and Geometric Blur (a new kind of blur, slightly slower, but with interesting results). Moreover, a new convolution-related concept has been introduced: Iterated Convolution of Vecinity - it means picking an initial value, iterating it with every pixel value in the vecinity of a main pixel and finally replacing the main pixel with the last iterated value; some particular cases for ICS are the Min/Max filters encountered in other image editing software.

Other effects, for specialized purposes:

• Resampling. Includes all filters, from linear to Spline, Lanczos and Gauss, with a user-defined window size.
• Text Rendering. Basic text rendering, with user-defined font, alignment and color/texture.
• Retouch. Two filters: SUSAN - eliminates noise without affecting din edges; Edge Enhance - enhances edges without contributing to noise.
• Gaussian JPEG Repair. Overlays a blurred version of the image on the original, in those areas which do not contain edges.