Computer graphics paper
I and a dear brother in faith of mine called Wellington Magalhães Leite wrote a paper titled: Influence of Tonal and Spatial Resolution on the Image File Size

See the original image we used to perform the tests regarding our paper:

The paper is accompanied by a spreadsheet and both are available in English and Portuguese.

See the paper's abstract below (English/Portuguese):

ABSTRACT

It is interesting to notice how the three variables (bits per pixel, number of colors and image file size) discussed in this paper are extremely related.

More and more we express ourselves through the use of images, which consequently need a place to be stored and this has to do with their usage in digital mediums as is the case of the Internet; take the Flickr service as an example. The storage is made in a digital form, that is, in bits.

It is known that: the better the image quality, the bigger will be the number of bits per pixel that are used to compose the image, what makes us capable of visualizing a great number of colors (tonal resolution), for the number of colors is coupled up to the quantity of bits per pixel. If we increase the number of pixels (spatial resolution) of the image, the generated file size will be bigger, in other words, more bits will be consumed to compose the image and depending on this value, the distribution or visualization of the image can be inadequate in certain conditions.

So, we can perceive the necessity of a case by case study, looking for a suitable value to the three variables, what will provide us with an ideal image file for each type of job.

Keywords: computer graphics, tonal resolution, spatial resolution, bits per pixel, number of colors, image file size

CONTENTS
1 INTRODUCTION 6
  1.1 Objective 6
  1.2 Definition 6
  1.3 Tonal resolution 7
  1.4 Spatial resolution 7
2 DEVELOPMENT 8
  2.1 Image edition 8
      2.1.1 Creating the work directory 8
      2.1.2 Obtaining the data “bits” for the experiment 8
      2.1.3 Selecting only the image of interest 8
      2.1.4 Opening the test file with Photoshop 9
      2.1.5 Visualizing the image size properties 10
      2.1.6 Redefining the image size 11
      2.1.7 Saving the modified image 12
      2.1.8 Producing images with different spatial resolution 13
      2.1.9 Altering the tonal resolution 13
      2.1.10 Returning to Windows Paint 14
      2.1.11 Producing images with different tonal resolutions 15
3 APPLICATION 16
  3.1 24, 16, 8, 4 and 1 bit tonal resolutions 16
  3.2 Tonal resolution vs. Spatial resolution vs. Image size 20
4 CONCLUSION 22
5 REFERENCES 23

RESUMO

É interessante notar como as três variáveis (bits por pixel, número de cores e tamanho do arquivo de imagem) discutidos neste trabalho estão intensamente relacionadas.

Cada vez mais nos expressamos através de imagens, as quais necessitam conseqüentemente de um local para serem armazenadas, haja vista a utilização em meio digital. Veja o site Flickr por exemplo. O armazenamento por sua vez é feito de forma digital, ou seja, através de bits.

É sabido que quanto maior for a qualidade da imagem, maior será o número de bits por pixel utilizados na composição da mesma, o que nos possibilita a visualização de um grande número de cores (resolução tonal), pois o número de cores está atrelado à quantidade de bits por pixel. Se aumentamos o número de pixels (resolução espacial) da imagem, maior será o tamanho do arquivo gerado, ou seja, mais bits serão consumidos para armazenar a imagem e dependendo deste valor, a distribuição ou visualização da imagem pode se tornar inadequada em certas condições.

Percebe-se então a necessidade de um estudo caso a caso, em busca de um valor adequado para essas três variáveis, de modo a obter um arquivo de imagem ideal para cada tipo de trabalho.

Palavras-chave: computação gráfica, resoulução tonal, resolução espacial, bits por pixel, número de cores, tamanho do arquivo de imagem

SUMÁRIO
1 INTRODUÇÃO 7
  1.1 Objetivo 7
  1.2 Definição 7
  1.3 Resolução tonal 8
  1.4 Resolução espacial 8
2 DESENVOLVIMENTO 9
  2.1 Edição de imagens 9
      2.1.1 Criando a pasta de trabalho 9
      2.1.2 Obtendo os dados “bits” para o experimento 9
      2.1.3 Selecionando somente a imagem de interesse 9
      2.1.4 Abrindo o arquivo de teste com o Photoshop 10
      2.1.5 Visualizando as propriedades do tamanho da imagem  11
      2.1.6 Redefinindo o tamanho da imagem 12
      2.1.7 Salvando a imagem modificada 13
      2.1.8 Produzindo imagens com diferentes resoluções espaciais 15
      2.1.9 Alterando a resolução tonal 15
      2.1.10 Retornando ao Paint do Windows 15
      2.1.11 Produzindo imagens com diferentes resoluções tonais 16
3 APLICAÇÃO 17
  3.1 Resoluções tonais de 24, 16, 8, 4 e 1 bit 17
  3.2 Resolução tonal vs. Resolução espacial vs. Tamanho do arquivo 21
4 CONCLUSÃO 23
5 BIBLIOGRAFIA 24

See the PivotChart created with the spreadsheet data:

You can get a PDF copy of the paper and the accompanying Excel spreadsheet at:

English version
http://leniel.googlepages.com/TonalSpatialResolutionImageFileSize.pdf
http://leniel.googlepages.com/TonalSpatialResolutionImageFileSize.xls

Portuguese version
http://leniel.googlepages.com/ResolucaoTonalEspacialTamanhoArquivo.pdf http://leniel.googlepages.com/ResolucaoTonalEspacialTamanhoArquivo.xls

Robot arm
A robot arm or robotic arm can be classified as articulated and not articulated. It’s more autonomous than a simple mechanic arm and can be used to lift small parts with high precision and velocity. It’s generally used in tasks such as: welding, painting, assembling, packaging, storage, product inspection and test and even in spacecrafts as can be seen below:

OpenGL
OpenGL (Open Graphics Library) is a standard specification that defines an API (Application Program Interface) that is multi-language and multi-platform and that enables the codification of applications that output computerized graphics in 2D and 3D.

Computer graphics paper
I and a dear brother in faith of mine called Wellington Magalhães Leite wrote a paper titled: Construction and Simulation of a Robot Arm with OpenGL

We used the Tao Framework C# biding to OpenGL during the construction of the robot arm.

See one of the screenshots of our robot arm:

See the paper's abstract below:

The importance of projects related to the field of Computer Graphics in simulations has been growing a lot during the last years. Therefore it brings to life the necessity of mastering the concepts and techniques inherent to the process of elaboration, construction and simulation of a given graphical project.

The OpenGPL API specification tries to help us when we are programming the graphical details of a given project. In this article we’re showing the necessary steps and routines to the proper codification and simulation of a robotic arm in 3D, which is the most employed robot in the manufacturing industry and in areas that require a high precision rate.

With a simulation (virtual) model, we can have a closer vision of the object of study in contrast with reality, what make us capable of foreseeing how a determined object will look like and how it will behave after its proper construction in the physical world.

Keywords: robot arm, OpenGL, 3D simulation, computer graphics

You can get a PDF copy of the article at:

https://github.com/leniel/leniel.net/blob/master/Uploads/ConstructionSimulationRobotArmOpenGL.pdf

Visual Studio C# Windows Application
You can get the Microsoft Visual Studio Project and the executables at:

https://github.com/leniel/leniel.net/blob/master/Uploads/RobotArmOpenGLCSharp.zip