Histogram is a chart representing a frequency distribution; heights of the bars represent observed frequencies. In other words a histogram is a graphical display of data using bars of different heights. It is similar to bar chart but it uses vertical column to display data. Unlike horizontal and vertical bar charts, the x-axis is not divided into mutually exclusive categories. The x-axis is a continuous scale. To construct a histogram, a section of the number line is divided into equal chunks, called bins. Note that for a histogram, the bins all must be the same width. Refer to the following diagram for better understanding of histograms.
CNET Download provides free downloads for Windows, Mac, iOS and Android devices across all categories of software and apps, including security, utilities, games, video and browsers. The histogram is a bar chart that shows the distribution of tones in an image. Black is on the far left edge, white is on the right, and everything else is in between.
Discover why Edraw is an awesome histogram maker: Download it Now.
Simple Histogram Maker - Make Great-looking Histogram
Edraw's histogram maker is used to show data visually, helping you organize your thoughts and simplify statistics analysis. It provides professional and infographic visuals to your graphs so that your presentation can be more persuasive. For those already accustomed with other Microsoft programs such as Word or Excel, the interface will be pretty intuitive. Simply drag and drop symbols, apply built-in designed themes, and automatically share your finished histogram into a presentation or PDF with one click.
System Requirements
Works on Windows 7, 8, 10, XP, Vista and Citrix
Works on 32 and 64 bit Windows
Works on Mac OS X 10.2 or later Best app to clean mac.
Attributes of Edraw Histogram Software
1. 1-click Creation
1-click creation cuts down 5 actions in traditional drawing software to 1 click action. That is 5 times faster! Marvelous!
1-click creation cuts down 5 actions in traditional drawing software to 1 click action. That is 5 times faster! Marvelous!
2. Quick-start Templates
Included are some histogram templates available to Edraw users. They will not only get you going quickly but guide you to create beautifully effective and presentation-quality histogram. Our diagramming community keeps adding templates every day. So you're sure to find something suitable to you.
Included are some histogram templates available to Edraw users. They will not only get you going quickly but guide you to create beautifully effective and presentation-quality histogram. Our diagramming community keeps adding templates every day. So you're sure to find something suitable to you.
3. All Necessary Symbols
Our object library comes with an awesome set of objects making it super easy to create histogram.
Our object library comes with an awesome set of objects making it super easy to create histogram.
4. Easy to Understand Graphic Results
We got beautifully designed icons for visually pleasing and comprehensible histogram. Sometimes, vivid pictures can maximize the impact on audience, which cannot be achieved by just words or numbers.
We got beautifully designed icons for visually pleasing and comprehensible histogram. Sometimes, vivid pictures can maximize the impact on audience, which cannot be achieved by just words or numbers.
5. Linkable Diagrams
The hyperlink function enables you to design histograms with working links. That means you can link to web pages or other files from your diagram. This makes it very easy to navigate back and forth between the relevant information. Thus, you can avoid confusion and saves a mass amount of time spent on redoing things.
The hyperlink function enables you to design histograms with working links. That means you can link to web pages or other files from your diagram. This makes it very easy to navigate back and forth between the relevant information. Thus, you can avoid confusion and saves a mass amount of time spent on redoing things.
6. Editable SVG Exports. Works Everywhere.
As a vector-based software, Edraw exports diagrams as SVG documents which can be styled and modified using Vector editors like Adobe Illustrator and Inkscape. The exported editable SVG files are fully fledged documents that can be viewed in any web browser as well as be imported into Microsoft Visio. One file format, infinitely accessible! Great!
As a vector-based software, Edraw exports diagrams as SVG documents which can be styled and modified using Vector editors like Adobe Illustrator and Inkscape. The exported editable SVG files are fully fledged documents that can be viewed in any web browser as well as be imported into Microsoft Visio. One file format, infinitely accessible! Great!
Histogram Template
Best Tips to Create Effective Histograms
Creating a histogram is an effective way of displaying univariate data in a visual way that reflects the data's frequency distribution. There are several variables to consider when creating histograms. To gain the optimal histogram, one needs to carefully consider the nature of the data, the analysis of the data, the preferences of the target audience, and software or resources available.
To prepare well, it is important to think about the nature of the data to be analyzed. Histograms are usually applied to show the distribution of univariate data sets. More specifically, histograms are a visual representation of the data's frequency distribution or probability density function. It is advisable for one to consider whether a histogram can represent the data best before constructing it.
If a histogram is exactly the best chart for representing the data, the next thing for consideration is the target audience. Teachers, engineering managers and businessmen may all have different expectations and demands. In all cases, easily readable labels on the axes and neat, precise construction are desirable.
Software packages can be used for creating a histogram quickly to save time and effort. Modern statistics programs offer a variety of services that extend beyond the construction of the histogram itself. These programs can produce color histograms and 3D infographics histograms. For professional work, Edraw charting software package is one of the ideal options because of its added sophistication in data analysis and the enhanced presentation.
Astrophotography is closer to science than art, and there is no such thing as “getting it right in camera.” This means you cannot simply point the camera at the sky and snap away.
In astrophotography you cannot avoid post processing your images, so stacking and editing your images serves three main purposes:
- Reduce noise and deal with light gradients and vignetting.
- Improve signal to noise ratio.
- Reveal the faint details in the image.
Image stacking is the technique used to improve the signal to noise ratio, and it is the only noise reduction method that will boost the image details rather than smear them out.
In this article, we will discuss some of the most popular software available for astrophotography image stacking.
Note: Don’t miss the detailed video at the end of this article, It was created to help show you how to quickly start using some of the stacking software mentioned in this article.
Click here to skip to our Image Stacking Demo Video.
Click here to skip to our Image Stacking Demo Video.
What Does Stacking Photos Mean?
The concept behind image stacking is simple, but to appreciate how it works, there are a couple of things we have to consider:
Histogram Download
- A stack can be visualized as a pile of images all stacked one on top of the other;
- Each digital image is formed by a set of pixels, all having a certain value: dark pixels will have a lower value than the bright ones;
In the simplest form of image stacking, the pixels values for all images in the stack are averaged to produce a single image.
What is the purpose of stacking photos?
The result is a single image with improved signal to noise ratio, i.e., with better details and lower (random) digital noise and better details.
The scheme below illustrates the concept.
If the considered digital noise affects the pixel values randomly across the stack, then the result of averaging the stack is that the random component of the noise to the pixel value is significantly reduced.
ISO noise and Luminance noise and Chrominancenoise are examples of digital noises that are random.
The image below shows a real-life example from stacking 30 images from my Sony RX10 bridge camera taken at ISO 6400. As you can see, the original images showed a greater deal of noise (grain) than the stacked one.
The More Images You Stack, The Better
The more images you stack, the cleaner the resulting images are, as shown in the comparison below.
While Image stacking creates a cleaner image, it often softens the image: digital sharpening techniques are then used to recover sharp looking details.
Finally, bear in mind that the progression of image quality is not linear.
If stacking 4 images improves the image quality of 50% respect what you got by stacking only 2 images, to improve a further 50% the image quality from stacking 50 images, you may need to stack 300 images or more.
Image Stacking And Movement
If nothing moves between shots, like in the previous real life example, implementing image stacking is very simple: just group the images and average them to smooth out the noise.
With a moving subject, grouping and averaging the images will not only smooth out the noise, but also the subject itself.
This is the same principle for which long exposures of passing traffic and crowd result in a street image without cars nor people.
This effect is amplified with the number of images used, and the moving subject could simply disappear from the stacked image.
https://oedjnqv.weebly.com/best-spam-blocker-app-for-mac.html. To resolve the issue, you have to align the images based on their content before stacking.
Due to image alignment, you may have to trim the edges of the stacked image to get rid of artifacts, but your target will not be lost.
Note that while in theory you can stack images of a static scene taken with the camera on a tripod, in reality, those images will probably differ at the pixel scale due to micro-movements. It is always beneficial to align the images before stacking.
How To Shoot For Exposure Stacking Your Images
Image stacking can be done with any camera and even camera phones and with images in both RAW and JPEG format.
Nonetheless, some things can be done to improve the final result:
- Lock the focus, so that the camera will not hunt for it between images. This will also help to keep the focus consistent through the shooting sequence.
- Keep the same settings, in particular shutter speed, aperture, and focal length: you don’t want to change the camera field of view during the sequence, nor the brightness of the images or the depth of field.
- If you are shooting on a tripod, disable image stabilization. If you want to shoot handheld, do so only for short sequences at very high shutter speed.
Image Stacking In Astrophotography
Related:Astrophotography Software & Tools Resource List
As said previously, image stacking is a standard technique implemented in any astrophotography editing workflow for,
- A star field from a fixed tripod.
- A deep sky object from a tracking mount.
- The Moon handheld.
- A starry landscape from a fixed tripod or tracking mount.
Every astronomy image will benefit from image stacking.
![Histogram App On Mac Histogram App On Mac](/uploads/1/3/4/2/134204219/141253185.png)
List Of Photo Stacking Software For Astrophotography
Here is a list of software used in astrophotography for image stacking.
Adobe Photoshop
Complete Image Editor | Commercial – Subscription Plan Photography Bundle $9.99 / Month | Mac OS X, Windows
Pro
- Versatile
- Available for Mac and Windows
- In bundle with Adobe Lightroom CC, Bridge, Camera Raw, and web space
- Many action packs and plugins available for astrophotography
Cons
- Subscription Plan only
- Can’t be used to calibrate light frames
- Stacking capabilities are somehow limited
If you are interested in photography, chances are you know Adobe Photoshop is the standard in the industry and does not need introductions.
With Adobe implementing a subscription plan for their applications, if you are using Lightroom CC for your everyday photography, your plan subscription will also include Photoshop CC and Bridge CC.
And for astrophotography, Photoshop is what you need. Lightroom cannot stack your images nor perform the histogram stretching, two crucial steps in the editing workflow for astrophotography.
In this article, we have already covered in detail how to stack astrophotography images with Photoshop.
Sequator
Deep Sky And Starry Landscape Stacker | Freeware | Windows
Pro
- Free
- Easy to use
- Fast
- Suitable for both Starry Landscapes and Deep Sky images
- Can create Star Trails
Cons
- Windows only
- Limited set of options
- Not suitable for Planetary astrophotography
Sequator is an easy-to-use and intuitive astrophotography software for stacking both starry landscape and deep-sky images. It can also be used to create star trails.
While not as advanced as other stackers, it nonetheless allows you to calibrate your light frames with dark and flat calibration frames. It also allows you to remove light pollution, reduce noise, and perform other simple tasks on the stacked image.
Starry Landscape Stacker
Starry Landscape Stacker | Commercial, $39.99 | Mac OS X
Pro
- Fast
- Easy to use
Cons
- Mac Os X only
- Does not read RAW files
If you are into starry landscapes and you are a Mac user, Starry Landscape Stacker is a must-have.
Easy to use, it allows you to stack and align the sky and the foreground independently by letting you easily mask the sky.
Unfortunately, the software lacks the support for RAW formats, thus forcing you to convert your RAW images in the more heavy TIFF format.
Aside from that, it works very fast and the final image is of good quality. You can also save the sky only, which is useful to further edit the shot in Photoshop or similar editors.
Starry Sky Stacker
Deep Sky Stacker | Commercial, $24.99 | Mac OS X
Pro
- Fast
- Easy to use
Cons
- Mac Os X only
- Does not read RAW files
- Basic
Starry Sky Stacker is Starry Landscape Stacker brother and it has been created to stack deep sky astrophotography images.
As Starry Landscape Stacker, Starry Sky Stacker is very easy to use and intuitive, although very basic.
If you are a casual star shooter and a Mac user, this could be a good choice for you.
Deep Sky Stacker
Deep Sky Stacker | Freeware | Windows
Pro
- Free
- Easy to use
- Fast
- Full light frames calibration
- Features Comet stack modes
- Can Drizzle
- Many advanced stack options and methods available
Cons
- Windows only
- Post-processing is quite limited
- Not suitable for Starry Landscapes nor for Planetary astrophotography
Deep Sky Stacker, better known as DSS, is arguably one of the most widely used software to calibrate and stack astrophotography images.
With DSS, you can fully calibrate your images with Darks, Flats, Dark Flats, and Bias calibration frames for the best results possible. Light frames are analyzed and scored by quality so that you can decide which percentage of best images you can stack (Best 75% by default).
A very interesting feature is that with DSS, you can easily combine images taken during different imaging sessions, to produce images of higher quality.
Autostakkert!
Planetary Stacker | Freeware | Windows
Pro
- Free
- Easy to use
- Suitable for Planetary, Lunar and Solar images
- Stack full planetary disk and lunar surface close-ups
Cons
- Interface a bit confused
- It does not offer wavelet sharpening
- Windows only
Autostakkert!, also known as AS!, is a very popular free software among the solar system astrophotographers. With AS! it is easy to stack both images showing the full Planetary (or Lunar or Solar) disc and images showing lunar surface close-ups.
The interface is a bit confusing, particularly in the beginning, but it is easy to navigate through the different steps for the stacking.
Unfortunately, AS! does not offer wavelet sharpening, which is a widely used technique in planetary and lunar astrophotography. How to delete downloaded apps. For this, you can load your stacked image in Registax, another freeware software for Windows only that, sadly, is now “abandoned-ware.”
Lynkeos
Planetary Stacker | Freeware | Mac OS X
Pro
- Free
- Has deconvolution and wavelet sharpening
- It is probably the only freeware planetary stacker for Mac OS X
Cons
- Not very intuitive
- Somewhat slower than Autostakkert!
Lynkeos is perhaps the only freeware planetary stacker software for Mac OS X, sparing you from turning to Windows for using Autostakkert!.
The interface is quite intuitive to navigate, but not when it comes to performing the different tasks.
On the other hand, it offers a deconvolution method and wavelet sharpening, a must-have for a planetary stacker. Definitely worth having a look at it if you are a Mac user.
SiriL
Deep Sky Astrophotography Editor | Freeware | Mac OS X, Windows, Linux
Pro
- Free
- Cross-Platform
- Active development
Cons
- A bit convoluted and not as intuitive as other stackers
SiriL is a freeware, cross-platform, astrophotography package that will let you calibrate, stack, and develop deep sky astrophotography images.
While not as easy and intuitive as Sequator or DSS, it offers a lot of options and produces good results. There is an active community, and it is under constant development.
Astro Pixel Processor
Deep Sky Astrophotography Editor | Commercial $60/Yr Renter License Or $150 Owner License | Mac OS X, Windows, Linux
Pro
- Full-grown astrophotography package
- Fairly easy to use
- Mosaics are created with ease and are of great quality
- Active and constant development
- Cross-Platform
- 30-days Trial period
- Affordable yearly subscription
Cons
- Only for deep sky astrophotography
- No Comet stacking mode
With Astro Pixel Processor (APP), you step in the realm of full-grown astrophotography packages, with many advanced options and methods to calibrate, stack, and post-process your deep-sky images.
Compared to PixInsight (PI), the software benchmark for the category, APP is cheaper and way easier to use, which makes it one of the best PI alternatives.
If you decide to buy it, you can choose between the renter’s license for $60/yr, to always get the latest version of APP, or the owner’s license for $150, but you will have to purchase the license again for major update releases.
PixInsight
Astrophotography Editor | Commercial – €230+VAT | Mac OS X, Windows, Linux
Pro
Canon Connect App Histogram
- It has all you need for astrophotography
- 45 days trial period
- A lot of tutorials and information available
Cons
- Expensive and without subscription plan
- Extremely steep learning curve
- Long and convoluted process
- Needs a powerful computer
When it comes to astrophotography, PixInsight is the software of reference against which all others are measured. It offers everything you may possibly need to produce pro graded images, and it is objectively the best software in the field.
But user experience can be frustrating, as the learning curve is very steep, the editing is long and convoluted, and your computer must be quite recent and powerful to make it run smoothly.
The €230 + VAT price tag is also quite steep: sure it is worth every penny, but this makes PI be even more the software of choice for professional and keen amateur astrophotographers.
A Comprehensive Demo About Image Stacking
In this video, I show you how easy it is to wet our feet with image stacking.
Photo Histogram
This is particularly true if you use Starry Landscape Stacker, Sequator, Deep Sky Stacker and Autostakkert!, as I showed in the video below.
Conclusion
Image Histogram Online
Image stacking is one of the crucial steps in the astrophotography editing workflow.
You’ll need the appropriate stacker for each type of astrophotography: starry landscapes, star trails, or deep-sky and planetary images.
In this article, we have covered the most popular astrophotography stackers available on the market, both freeware and commercial.
And while Windows users have the more extensive choice, some notable stackers are available for Mac and even Linux users.