1 CS 248 – Project 1 Help Session (demo) (demo) Painting RGB and HSV sliders Brush visualization Weighted mask driven painting HSV checkboxes

2 Basic painting Brush region

3 Simple tinting (alpha blending) Like painting with partially transparent paint. C new = (1-  ) C old +  C paint Compositing equation

4 Mask driven painting Different pixels of the brush behave differently. Paint every pixel in the brush region Paint only some of the pixels

5 Weighted mask driven painting Mask contains alpha for each pixel in brush (visualization of this )

6 RGB vs. HSV interpolation C R = (1-  ) C R +  paint R C G = (1-  ) C G +  paint G C B = (1-  ) C B +  paint B C H = (1-  ) C H +  paint H C S = (1-  ) C S +  paint S C V = (1-  ) C V +  paint V RGB interpolation HSV interpolation (Does it make a difference?)

7 Interpolating in HSV and RGB Hue Saturation

8 Painting in HSV and RGB Hue Saturation HSV RGB

9 Tinting (HSV checkboxes) Choose which HSV components to affect. if (H_check) { C H = (1-  ) C H +  paint H } if (S_check) { C S = (1-  ) C S +  paint S } if (V_check) { C V = (1-  ) C V +  paint V }

10 Requirements Correctness (40%) Correctness (40%) Don’t crash Implement all required features (Read the directions like a lawyer) Efficiency (20 %) Efficiency (20 %) No noticeable lag while using your application User Interface (20%) User Interface (20%) Programming Style (20%) Programming Style (20%) Copying code (Don’t do it) Submitting with ‘freeze’ and ‘submit’ Submitting with ‘freeze’ and ‘submit’

11 Extra credit (Filter painting) Blurring the image under the brush.