Instructions and Qualification Test for Sharpness and Contrast Adjustment in Painterly Rendering

Your task is to compare the sharpness and contrast of shiny materials shown in two images. One image has been created using a painterly rendering algorithm.
This qualification test is designed to explain what we mean by "painterly rendering" and "shiny materials".

Painterly rendering

A painterly rendering algorithm gives to an image the look of a painting. Here are a few examples that use brush strokes of various sizes:

Original image ("realistic rendering") Painterly rendering

Which image has been painted with the largest brush strokes?

Tomato

Beach

Sunflower


Shininess

A shiny object has the appearance of a mirror with reflective highlights, while a matte object has the appearance of clay. Here are a few examples of shiny and matte objects:

These spoons are very shiny These cats are matte


Contrast and Sharpness

Highlights on shiny objects can vary in two ways.
1) The sharpness of the highlight can vary. For example, the highlight on the first teapot is very smooth, while it is much sharper on the second one.

This teapot has smooth highlights This teapot has sharp highlights



In the following example, select the abstract shape that has the sharpest highlights.

Shape A Shape B

Which shape has the sharpest highlights?

Shape A has sharper highlights

Shape B has sharper highlights



2) The contrast of the highlight can also vary. Here the sharpness of the highlight is fixed but the contrast varies between the two abstract shapes.

This shape has low-contrasted highlights This shape has high-contrasted highlights



The following images show two abstract shapes with different levels of sharpness and contrast in their highlights. Your task is to adjust the sharpness and contrast of the right image so that it matches the sharpness and contrast of the left image. Click the arrows to increase or decrease the sharpness and contrast of the right image. Take the necessary time to explore the effect of each slider. Once you are done adjusting the sharpness and contrast, scroll down to see the correct answer.


 
  Sharpness  
  Contrast  



The answer is:


Sharpness
Contrast



Here is a second example:


 
  Sharpness  
  Contrast  



The answer is:


Sharpness
Contrast





Finally, in this third example, the left image is rendered in a painterly style. Try to adjust the sharpness and contrast of the realistic image until it matches the painterly image.


 
  Sharpness  
  Contrast  




The answer is:


Sharpness
Contrast



Do you understand the task?

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