Problem 682. Image Processing 002 : Fix Vignetting in a Visible Sensor

Created by Richard Zapor

Solve Later

{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","relationshipId":"rId2","target":"/matlab/output.xml"}],"parts":[{"partUri":"/matlab/document.xml","relationship":[],"contentType":"application/vnd.mathworks.matlab.code.document+xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\"?><w:document xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:body><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>The task is to correct image files for Visible scanning sensors that due to errant tolerancing produce vignetted(V) images. The V artifact is in a converging ray bundle and only the edges are impacted to differing amounts. The obscuration varies cross-scan but is constant for all samples. Sensor package repair is cost prohibitive. Luckily, the Image Processing is Matlab based and needs only a fast function to perform the V adjustment good enough for govt work.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>Output: Fixed image(Fimg) (Array &lt;= 512x512 of type double)</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>Input: Vignetted Image file(Vimg) (double); Obscuration (1xncol)</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>Tolerance: Good enough is 1%+1 count of Truth (Timg)</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>Obscuration: Max is 25% at edge, Min 8 columns wide.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>Vignetted Image creation: Start with Truth (Timg)</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>Vimg = Timg(1-Obscuration)</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>example: Obs = [.25 .1 0...0 .1 .25]; obs [50 20 0...0 20 50];</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>load penny.mat; Timg=double(P);</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>Vimg=Timg.*repmat(1-Obs,128,1)</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>The Cody \"Image processing 001\" for an IR and using In-scene data was not intended to be so complex. This and its successor should have appeared prior to \"001\".</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>This Visible Vignetting correction is very direct.</w:t></w:r></w:p></w:body></w:document>"},{"partUri":"/matlab/output.xml","contentType":"text/xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?><embeddedOutputs><metaData><evaluationState>manual</evaluationState><layoutState>code</layoutState><outputStatus>ready</outputStatus></metaData><outputArray type=\"array\"/><regionArray type=\"array\"/></embeddedOutputs>"}]}

The task is to correct image files for Visible scanning sensors that due to errant tolerancing produce vignetted(V) images. The V artifact is in a converging ray bundle and only the edges are impacted to differing amounts. The obscuration varies cross-scan but is constant for all samples. Sensor package repair is cost prohibitive. Luckily, the Image Processing is Matlab based and needs only a fast function to perform the V adjustment good enough for govt work.Output: Fixed image(Fimg) (Array &lt;= 512x512 of type double)Input: Vignetted Image file(Vimg) (double); Obscuration (1xncol)Tolerance: Good enough is 1%+1 count of Truth (Timg)Obscuration: Max is 25% at edge, Min 8 columns wide.Vignetted Image creation: Start with Truth (Timg)Vimg = Timg(1-Obscuration)example: Obs = [.25 .1 0...0 .1 .25]; obs [50 20 0...0 20 50];load penny.mat; Timg=double(P);Vimg=Timg.*repmat(1-Obs,128,1)The Cody "Image processing 001" for an IR and using In-scene data was not intended to be so complex. This and its successor should have appeared prior to "001".This Visible Vignetting correction is very direct.

The task is to correct image files for Visible scanning sensors that due to errant tolerancing produce vignetted(V) images. The V artifact is in a converging ray bundle and only the edges are impacted to differing amounts. The obscuration varies cross-scan but is constant for all samples. Sensor package repair is cost prohibitive. Luckily, the Image Processing is Matlab based and needs only a fast function to perform the V adjustment good enough for govt work.

Output: Fixed image(Fimg) (Array <= 512x512 of type double)

Input: Vignetted Image file(Vimg) (double); Obscuration (1xncol)

Tolerance: Good enough is 1%+1 count of Truth (Timg)

Obscuration: Max is 25% at edge, Min 8 columns wide.

Vignetted Image creation: Start with Truth (Timg)

Vimg = Timg(1-Obscuration)

example: Obs = [.25 .1 0...0 .1 .25]; obs [50 20 0...0 20 50];

load penny.mat; Timg=double(P);

Vimg=Timg.*repmat(1-Obs,128,1)

The Cody "Image processing 001" for an IR and using In-scene data was not intended to be so complex. This and its successor should have appeared prior to "001".

This Visible Vignetting correction is very direct.

Solve

Solution Stats

34 Solutions
9 Solvers

Last Solution submitted on Sep 19, 2021

Last 200 Solutions

Problem Comments

Problem Recent Solvers9

Problem Tags

image processing optics bsxfun

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 682. Image Processing 002 : Fix Vignetting in a Visible Sensor

Solution Stats

Last 200 Solutions

Problem Comments

Problem Recent Solvers9

Suggested Problems

More from this Author255

Problem Tags

Community Treasure Hunt

Problem 682. Image Processing 002 : Fix Vignetting in a Visible Sensor

Solution Stats

Last 200 Solutions

Problem Comments

Problem Recent Solvers9

Suggested Problems

More from this Author255

Problem Tags

Community Treasure Hunt

Players