medical illustration plme 0400 drawing 4 colors and shades...
TRANSCRIPT
Introduction to Medical Illustration
PLME 0400
Drawing 4Colors and Shades of gray
• Textures:– Hard and shiny surfaces have clear shadow lines and light reflexes
– Soft surfaces have less clearly defined lines– Fluffy objects have fluffy contours
Light, light reflex, shadows
Light, light reflex, shadows
Core dark
Cast shadow
Specular highlight (reflex)
Intermediate (halftone)
Penumbra
Ambient shadow
Reflected lightReflection
1. How does value relate to light and form (value structure: “how gray is it?”)
2. How does value relate to local color(Hue/Value/Chroma)
Value Structure
Value Structure• Two camps: light and dark
Simultaneous Contrast:We overstate the difference in adjacent values
Value Structure
Simultaneous Contrast:We overstate the difference in adjacent values
Value Structure
Simultaneous Contrast:We overstate the difference in adjacent values
Value Structure
Simultaneous Contrast:We overstate the difference in adjacent values
Value Structure
• Clear hierarchy of lights and darks
• Clear and consistent light mass and shadow mass
• Lightest part of the shadow mass is still darkerthan the darkest part of the light mass, andviceversa
Value Structure
DarkerLighter
Stanley SpencerSargent
Max Brodel
• Three factors:– Hue: What color is it? (red, purple, magenta, green)– Chroma: How intense is the color (how green)– Value: How light or how dark is the color
• Shade: color + black• Tint: color + white
Color
• Three factors:– Hue: color temperature – warm v. cold
Color
• Three factors:– Hue: color temperature – warm v. cold– Chroma is almost the same as saturation
Color
• Three factors:– Hue: color temperature – warm v. cold– Chroma is almost the same as saturation– Value is similar to grayscale: how dark is it?
Color
• Three factors:– Hue: color temperature – warm v. cold– Chroma is almost the same as saturation– Value is similar to grayscale: how dark is it?
Color
• Not all colors are created equal• At its highest chroma (saturation),
– Purple is the darkest color (highest value)– Yellow is the lightest color (lowest value)
• A “really purply” purple is very dark• A “really yellowy” yellow is very light
Color v. Grayscale
• Not all colors are created equal– Doppler effect in ultrasound
• Sound waves reflecting off moving objects change frequency• Shorter if obect moves toward tranducer• Longer if object moves away from transducer
Color v. Grayscale
• Not all colors are created equal– Doppler effect in ultrasound
• Sound waves reflecting off moving objects change frequency• Shorter if object moves toward transducer• Longer if object moves away from transducer
Color v. Grayscale
• Not all colors are created equal– Heat maps (over/underexpression of genes
Color v. Grayscale
• Not all colors are created equal– Heat maps (over/underexpression of genes
Color v. Grayscale
Color is subjective
Color is subjective
Arteries v. Veins
• Red v. blue?
Arteries v. Veins
• Red v. blue?
Arteries v. Veins
• Red v. blue?
• Translate from color to grayscale
Medical illustration
• Translate from color to grayscale
Medical illustration
• Translate from color to grayscale
Medical illustration
• Translate from color to grayscale
Medical illustration