Pixelation of bitmap images (pixel size, pixel density, resolution)

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Discussion Overview

The discussion centers around the causes of pixelation in bitmap images when they are enlarged, exploring the relationship between image resolution, screen resolution, pixel size, and pixel density. Participants examine both theoretical and practical aspects of how these factors contribute to the visual quality of enlarged images.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose that pixelation occurs due to the enlargement of graphical pixels, which occupy multiple physical pixels on the screen.
  • Others argue that the relationship between image resolution and screen resolution is crucial, with some suggesting that a higher image resolution can mitigate pixelation effects.
  • A later reply questions whether the size of the pixels on the screen plays a role in pixelation, with mixed responses regarding its significance.
  • Some participants mention the importance of filtering techniques, such as the Nyquist Post Filter, in reducing perceived pixelation when displaying images.
  • There is a discussion about the impact of viewing distance and screen size on the visibility of pixelation, with some asserting that proper filtering can make pixel edges less noticeable.
  • Participants note that the information content of the image, defined by its pixel count and bit depth, is a fundamental factor in determining resolution and quality.
  • Some contributions highlight that the quality of the camera and image processing techniques can influence the perceived quality of the image displayed.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the causes of pixelation and the factors that influence it. There is no consensus on the primary reasons for pixelation or the effectiveness of various solutions proposed.

Contextual Notes

Limitations in understanding arise from differing definitions of resolution and pixel density, as well as the complexities involved in image processing and display technology. The discussion also reflects varying levels of familiarity with technical concepts related to image quality.

Who May Find This Useful

This discussion may be of interest to individuals studying digital imaging, graphic design, or anyone involved in fields where image quality and resolution are critical, such as photography or display technology.

  • #31
.Scott said:
All common TV camera's create horizontal pixelation
I'd say it's more like Sampling. "Pixellation" only applies to 2D data and TV moves, so the temporal requirements are very relevant. If they wanted to just increase the resolution, they could slow the horizontal scan rate and use more lines - which would make movement even more jerky and flickery.
This is one of those topics that is very hard to keep on the rails of 'one point at a time'.
 
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  • #32
sophiecentaur said:
The speed of a convoy is the speed of the slowest ship.
I'll open up Pandora's box a bit.
When analyzing the effects of image capture, transmission, storage, retrieval, processing, and viewing, heavy use is made of the spatial frequency domain. In essence, each spatial frequency is a separate "convoy" - unless you want to open the Box all the way.

This is all grist for a course in Digital Signal processing - which I suspect both of us have taken.
 
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