How to measure the number of pixels involved in a selected area of a digital photo?

Hi everyone. I want to determine the number of pixels in an object that is part of a digital photo. I use cameras to film chunks of ice breaking away from ice cliffs or tidewater glaciers. I want to know the size of the ice chunk that my digital photographs capture. I know the width and height of the ice cliff in metres already, so I was thinking that I could convert the equivalent of 1 pixel : ? metres - this is really what I want to do. That way every time I see a chunk of ice breaking off, I can pull up the photo, outline the chunk, calculate how many pixels fill the area of ice removed by the chunk breaking off and convert to metres area 2 - thus giving me my size order. If anyone has ideas on how to do this I would really appreciate it, thanks so much community. I was thinking that Photoshop or Fireworks could help me with this, Ricky

Hi SIlkrooster,
Thanks for responding and giving a suggestion,
I followed your approach (see attached screen shot) , Image, Image Size, and found that approximately 37 pixels = 1 centimetre. So just to be clear - if I measure a straight line with the ruler tool that is say 10cm long, I can simply do: 10 cm * 37 pixels (1cm equivalent) = 370 pixels for the straight line. Do you agree?
Do you agree?

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How to determine the number of pixels of a desired object within a digital photograph?

Hi everyone. I want to determine the number of pixels in an object that is part of a digital photo. I use cameras to film chunks of ice breaking away from ice cliffs or tidewater glaciers. I want to know the size of the ice chunk that my digital photographs capture. I know the width and height of the ice cliff in metres already, so I was thinking that I could convert the equivalent of 1 pixel : ? metres - this is really what I want to do. That way every time I see a chunk of ice breaking off, I can pull up the photo, outline the chunk, calculate how many pixels fill the area of ice removed by the chunk breaking off and convert to metres area 2 - thus giving me my size order. If anyone has ideas on how to do this I would really appreciate it, thanks so much community. I was thinking that Photoshop or Fireworks could help me with this, Ricky

Thanks gener7 and normfb.
The Photoshop help measurement page is brilliant and I think I can use the info on that page to work out my iceberg sizes. Check out the attached photo - you are looking at an ice cliff - essentially the front of a tidewater glacier that flows in the ocean. I'm a research student and I look at the process of iceberg calving - this is the term we use to define the sudden breaking away or detachment of ice chunks from glaciers that end in the sea.
I used the lasso tool to crop the area of ice lost as a single chunk of ice detached from the ice cliff. At the same time I had the histogram window open. The histogram showed me how many pixels were contained in the cropped area. What I need to do now is work out what 1 pixel is equivalent to in metres. Soon I will have a digital elevation model for the ice cliff that will offer centimetre to metre scale resolution of the surface topography - so that should really help. The photographs I have are taken every 30 seconds - which is brilliant for documenting how the geometry of the ice cliff adjusts in response to detaching ice pieces and also because the ice is moving. I am a research student in Canada, and at the time I took the photos we measured that the ice cliff was advancing at a rate of approximately 12 metres per day! That's pretty fast. The flow of the ice is a first order control on the rate of iceberg production - you are essentially pushing ice into the ocean where it breaks off. I'm having to learn everything Photoshop from scratch...so please bare with me because maybe some of the photoshop questions I ask are simple to most!
I noticed the "integrated density" function on the help sheet you suggested. This function also provides the square number of pixels contained in the cropped area I select...I guess this is similar to the histogram right?
Either way - i just need the scale conversion to go from 1 pixel : metres or cm equivalent. At that point I think I will have to manually select every single iceberg event from my time-lapse photos and do this the manual way! I have about 800 events to manually digitise and calculate the area for...
Thanks everyone, Ricky

How to measure the number of ping over a interface

Hello
I need to setup a measurement of the number of ping that goes throug an ethernet interface over a duration of 3min
How can I do that ?
thanks for help

Hello
thanks for help
I have an application which sent pings to hundred of routers to test connectivity for pro-active monitoring purpose. there are some strange performance problem on this application and I want to measure the number of pings sent during a time interval

How can I export the number of pixels of each layer into an excel file?

I would like to export the number of pixels that each layer of an image contains into excel. How can I do this?
Secondly, as I need to do this with several images, is there any way to name the layers so that all layers with let's say for example the name "yellow" appear in the same column in excel?
Some background information on why I need to do this... I would like to know how many percent of an image are yellow and have therefore created layers of one image for each color it contains.
Thanks for your help!!!

Maybe my question was a bit unclear. I do not want to find out the number of pixels of a color in a layer but the number of pixels of the complete layer.
What color these layers are is a different question. I am using images with a very limited range of colors (sort of like the image above but with about 10 colors). I have seperated these colors into layers and now need to count the pixels of each layer and export them.
You can record number of pixels/layer into the Measurement Log, then export data to Excel. But I'm not sure how to automate that without scripting.
Does anyone know how to do this?
For normal artLayers it is somewhat easy to get the number of pixels in the layer. But that is just how many pixels are in the layer.
But that is exactly what I need to know, how many pixels are in the layer. I know how to find this out by looking at the histogram of the selection. But I want to export this information of all layers at once into an excel or text file. Any ideas on how to automate this with or without scripting?
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How do I reduce the number of pixels in my photos?

How do I reduce the number of pixels in my photos?

Export them at a smaller size:
File -> Export - not the options at 'Size'
Regards
TD

How can I find out the number of pixels a photo has in i photo.

How can I find out the number of pixels a photo has in iphoto.

Do you mean in iPhoto on the MacBook Pro?
The dimensions (width and height iin pixels)are shown in the "Info" panel - multiply the two numbers:
Regards
Léonie
P.S: on an IOS device you see the same information in iPhoto, when you select the photo in an album and click th Info button ( i ).

How can I increase the number of pixels in an image?

How can I increase the number of pixels in an image?

You can't.
The number of pixels in an image is decided by the camera that shoots the image
With an app like Photoshop you can interpolate - this will make a guess as to what a particular pixel may look like based on the ones around it. Results can vary wildly and Photoshop is expensive.
Regards
TD

How to adjust the green (starting) and the red (end) rectangles pixel by pixel (top, bottom, left and right) by changing the number of pixels in ken burns.

How to adjust the green (starting) and the red (end) rectangles pixel by pixel (top, bottom, left and right) by changing the number of pixels in ken burns. Help please.

If you look closely at the top of the canvas pane, as you move either of the boxes (green or red) there is an indication of pixel positions... "top, bottom, left, right," and "scale."
Admittedly, it doesn't seem as if you can "enter" the dimensions with your keyboard, however, as you move the boxes, you have a real time indication of the boxs' locations.
(I couldn't take a screen shot, as you have to actively move the box with a mouse or other input device... thus, I could not also take a screen shot with same device.)
I hope this helps.

How do I reduce the number of pixels in a JPG so I can email it?

I am unable to reduce the number of pixels in a JPG so I can email it
== This happened ==
Every time Firefox opened
== 2 days ago

If you do not have an image editor that allows to do that then use one of the online sites to resize images.
* http://www.shrinkpictures.com/
* http://www.picresize.com/

How to measure the performance of sql query?

Hi Experts,
How to measure the performance, efficiency and cpu cost of a sql query?
What are all the measures available for an sql query?
How to identify i am writing optimal query?
I am using Oracle 9i...
It ll be useful for me to write efficient query....
Thanks & Regards

psram wrote:
Hi Experts,
How to measure the performance, efficiency and cpu cost of a sql query?
What are all the measures available for an sql query?
How to identify i am writing optimal query?
I am using Oracle 9i... You might want to start with a feature of SQL*Plus: The AUTOTRACE (TRACEONLY) option which executes your statement, fetches all records (if there is something to fetch) and shows you some basic statistics information, which include the number of logical I/Os performed, number of sorts etc.
This gives you an indication of the effectiveness of your statement, so that can check how many logical I/Os (and physical reads) had to be performed.
Note however that there are more things to consider, as you've already mentioned: The CPU bit is not included in these statistics, and the work performed by SQL workareas (e.g. by hash joins) is also credited only very limited (number of sorts), but e.g. it doesn't cover any writes to temporary segments due to sort or hash operations spilling to disk etc.
You can use the following approach to get a deeper understanding of the operations performed by each row source:
alter session set statistics_level=all;
alter session set timed_statistics = true;
select /* findme */ ... <your query here>
SELECT
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         OBJECT_NAME,
         CARDINALITY,
         LAST_OUTPUT_ROWS,
         LAST_CR_BUFFER_GETS,
         LAST_DISK_READS,
         LAST_DISK_WRITES,
FROM     V$SQL_PLAN_STATISTICS_ALL P,
         (SELECT *
          FROM   (SELECT   *
                  FROM     V$SQL
                  WHERE    SQL_TEXT LIKE '%findme%'
                           AND SQL_TEXT NOT LIKE '%V$SQL%'
                           AND PARSING_USER_ID = SYS_CONTEXT('USERENV','CURRENT_USERID')
                  ORDER BY LAST_LOAD_TIME DESC)
          WHERE ROWNUM < 2) S
WHERE    S.HASH_VALUE = P.HASH_VALUE
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ORDER BY ID
/Check the V$SQL_PLAN_STATISTICS_ALL view for more statistics available. In 10g there is a convenient function DBMS_XPLAN.DISPLAY_CURSOR which can show this information with a single call, but in 9i you need to do it yourself.
Note that "statistics_level=all" adds a significant overhead to the processing, so use with care and only when required:
http://jonathanlewis.wordpress.com/2007/11/25/gather_plan_statistics/
http://jonathanlewis.wordpress.com/2007/04/26/heisenberg/
Regards,
Randolf
Oracle related stuff blog:
http://oracle-randolf.blogspot.com/
SQLTools++ for Oracle (Open source Oracle GUI for Windows):
http://www.sqltools-plusplus.org:7676/
http://sourceforge.net/projects/sqlt-pp/

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windows app store how to measure the size of a string?
string str = "Hello word windows app store";

if you need the actual width the string occupies in pixels than use (see
this MSDN link for more details):
Graphics.MeasureString(String, Font)
if you only need the "length" of the string i.e. no. of characters than use (see
this MSDN link for more details):
str.Length
dont forget to bing / google :)
hope this helps!
Graphics.MeasureString(String, Font) can not use in windows store app.
TextBlock has Measure()
method, as following:
Size MeasureString(string content, Size availableSize, double fontSize, string fontFamily="Segoe UI")
    TextBlock tb = new TextBlock();
    tb.TextWrapping = TextWrapping.Wrap;
    tb.Text = content;
    tb.FontFamily = new Windows.UI.Xaml.Media.FontFamily(fontFamily);
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Test:
string str = "Hello word windows app store";
Size size = MeasureString(str, new Size(800, 600), 40);

How to measure the InfoCube size?

can any body help me regarding this
how to measure the info cube size?

1. use transaction se16, infocube table /../f[infocube name] and /.../e[infocube name], count 'number of entries' - total records
use transaction db02 tablename infocubename - size in bytes
Re: how can we measure the info cube size
2. asap methodology
Re: Lifecycle Implementation
hope this helps.
regards
harikrishna N

How to count the number of cycles in sine wave

Hi,
I am new to Labview. I have labview 8.2 version and my dataacquisition is NIDAQPAD6015. I could write a program to generate a sine wave of desired frequency through simulate signal. My question is how do i measure the number of cycles for this sine wave as soon as I run the program. Hope my question is clear.
Ravi Mokirala

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Capture more than one cycle. Find the min and max values. Subtract Min from Max and divide by 2. Then subtract this result from the Max value (or add the result to the Min value). This is the offset.
To count the number of cycles where the offset is unknown, just use the first data point value as a reference. If the next data point is more positive, then count the number of times that the first data point is repeated and the next data point is more positive. Of course with DBL data type, you probably would not get the exact same value as the first data point, so you need to use In Range with a very tiny limit. It all depends on your signal amplitude, frequency, and sampling rate.
Example: Lets say your first data point value is 0.5 and the 2nd point is 0.55. You need to look for another value that is between 0.48 and 0.52. Then read the very next data point value. If it is greater than the previous value, add one to the cycle count. If it is less than, you are at half a cycle, do not add to the count.
- tbob
Inventor of the WORM Global

Counting the number of pixels in a certain range within an ROI

I am using Vision 6.0 for Visual Basic.
I would like to get a count of the number of pixels within a particular region whose value falls within a certain range (e.g., the number of pixels with values between 86 and 255).
Can anyone tell me how I can do this?
Thanks.

bep -
Have you looked at the Histogram example? It should be under the Analysis directory wherever the examples are.
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Dim Histogram As Variant
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CWIMA
QVision1.Histogram2 CWIMAQViewer1.Image, HistogramReport
Histogram = HistogramReport(1).Histogram
' Now Histogram(5) contains the number of pixels in the 5th bin.
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Greg Stoll
IMAQ R & D
National Instruments
Greg Stoll
LabVIEW R&D

How to measure the frequency of the data plotted on the waveform chart

i have made a virtual instrument in labview that acquire data (say sine wave) into a spreadsheet file and also on the chart from the function generator. I measured the frequency of the data from the chart but it is coming out to be very less. How can i calculate the frequency of the plotted sine wave and also from the spreadsheet file.

If you want to get an idea of the base-frequency of an periodic signal, you can measure the number of samples in between two maxima or in between two minima of the periodic signal.
Multiply the number of samples by the sample-interval (1/Fsample in [sec]) gives you a rough estimate.
FFT, I mentioned is one of the more advanced calculation-methods.
The method calculates the spectrum from a waveform.
Hope this helps,
Patrick

How to measure the number of pixels involved in a selected area of a digital photo?

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