Python - Table of Contents

Section dedicated to Python and image manipulation

Gray-level images

In this series dedicated to digital image, gray level images are the most common images used in ImageJ.

Signed, Unsigned pixel values

Among the various image types proposed to import a gray-level image, even though you know the dynamic range of your image, you have to choose 'signed' or 'unsigned'...

Endianness

In this series of posts dedicated to image file, the endianness is one of the parameters available in the Import dialog box. What is this strange 'little-endian byte order'?

Image File: TOC

Table of Contents of a series of posts dedicated to the image file.
When you saved an image - 2D array containing pixel values - in your hard disk, this array is converted into a new structure: the file...

Test image: bump and hill

A simple test image useful to try various algorithms of gradient, edge detection,...

CMY(K) color image

CMY (or its variant CMYK) color space uses as primary colors: cyan, magenta, and yellow.
This color space used by printers is interesting because, this is an example of a subtractive color model. When you add color(s), you converge towards black color.

Exploring colors and grays with ImageJ

 How are stored the grays and colors in a digital image? This simple question is explored in this post thanks to the IJ programming language.

Numbers: binary, decimal, hexadecimal

Numbers used by computers and by extension by programming languages can be represented in different radix (base). Usually, the decimal notation is the most convenient - specially for human beings - but in certain circumstances, it's better to use the binary or hexadecimal notations.

Color wheel

Painters and computer artists, often use a color wheel which is composed of color hues arranged along a circle. There are some interesting features in such a presentation of this color table (also available in the HSV/HSL color space): primary, secondary, and complementary colors...

Indexed color images

After RGB images, indexed color images are another way to display/work with colors in ImageJ.

Digital Image

Table of contents of Digital Image


In image processing softwares like ImageJ, what's a digital image? how the grays, colors are encoded? how these data are stored in a file?

Color images: RGB image

After the binary [Link] and gray-level images, the color images represent the last (and the most sophisticated) family of images used in image processing softwares. Colors are obtained by the combination of three primary colors. The latter may be different depending of the device displaying/printing the image.
In ImageJ, the most usual color images are encoded with the RGB color space.

Binary images

Binary images (black and white) are everywhere in ImageJ, they are required in Analyze > Analyze Particles, have their own operators and functions.
This post explains what they are and how to use them...

Black and White, TRUE or FALSE?

When playing with binary images in ImageJ, that's not really simple to remember if TRUE corresponds to white or black (specially, if you use a lot of different binary functions). Here are simple examples to try to understand how it works.

Boolean operators

One of the basic functions for binary images (containing TRUE and FALSE pixels) are the boolean operators useful to manipulate this kind of images.