magick | ImageMagick bindings for Go | Computer Vision library

I previously posted how to auto fix a skewed image, is there a way to simply detect that it is skewed with image magick? I.e. is there a command that I could run on two images, one skewed and one not, and use that output as the determinant of whether it's skewed?

Thanks for any help, Kevin

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In a previous question I was provided with a small script by sean-7777 Creating a selected tab in a HTML tabstrip. It works the way he wrote it, but there are 2 issues with it.

First, while it looks for the 'current' class in the TD, it only applies it to the A tag. Second, if I add 'current' to the A tag the script does not find it, but does find it if I add it to the TD tag.

In my CSS I had to apply the :hover class to both the TD (.td1:hover) and the A (.anchor:hover) in order to get the colors I wanted. The A tag overrides the TD when it comes to the text color and that is why I had to apply the hover css to both.

I can preselect the "selected tab" by including the current class to both the TD (class='td1 bold center smaller current') and the A (class='anchor current'), but the script does not remove it when I click another tab, and as I stated above, if I only add it to the A tag the script does not find it, and if I add it only to the TD the link text does not reflect the selected color.

If I click the pre-selected tab after clicking on another tab then the script will remove the hilite when I next click on a different tab. I have been trying different things, but my lack of knowledge of this version of JavaScript is making it impossible to get anything to work properly.

So my questions are:

1. How do I get the preselected tab to de-select when I click another tab?
2. How do I get the 'current' class to be added and removed from both the TD and the A tags?

Edit: I finally got the cascading thing figured out. Changes in the CSS below. The script still looks for the current class in the TD but only applies it to the link text in the A tag. The pre-selected tab still remains hilited on the link text, TD de-selected, when you click another link. I believe this is also the script, and still doesn't deselect entirely until after clicking on it a second time and then clicking a different tab.

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17 Feb 2022: It took me awhile but I figured out what's going on. Each TD has an anchor (A tag) and both the TD and the anchor have classes. The anchor only has one class, but it is being applied last, so the TD apparently has that class as part of its class list. As a result the current class is being applied to the anchor tag, not the TD. I have yet to figure out what to do about this. The 'current' class needs to be applied to the TD before the anchor class, not after. But this may affect what happens. The anchor text color may override the selected text color, and so I am unsure of what to do to correct this.

19 Jan 2022: I thought it was fine, but there is an issue I didn't notice until I started applying this to another page I have that has two rows of tabs and some of them have more space either side of the link text. It wasn't so prevalent when the link text occupied the majority of the space within the cell.

If you click the link text the page gets updated to show the new document, but the only part of the tab that gets hilited is the link text. The remainder of the area of the cell remains the unselected color.

If you click the area around the link text the entire cell background gets hilited but the link text color doesn't change to the hilite color and the page does not get updated to show the new document (the link does not get followed).

The script is building a list of all td.td1 classes. The link is within that but is not the same class. How do I get the script to treat the entire cell as what was clicked and update both the cell and the link text when either the link or the cell area are clicked, and how do I get a click in the cell area to be treated as a click of the link?

The page I am working on is still a frameset page. I am working on doing the same thing with it that I did with the other page, but there are 33 sheets to deal with in this one so it will take me a while to get it to a iframe page. Here is the link to the page as it is now so you can see what I am talking about. The script code is the same and any change made to the code already placed in this thread will be useful for this page.

17 Jan 2022: Final solution: It wasn't working because the script needs to run *after* the page loads, not before. The easiest solution is to put the script after the table (before the closing body tag), but (as sean-7777 pointed out in his latest comment) you can also have the document loader not run the script until the page has loaded. I chose to put the script after the table. And it works in both the frameset and iframe versions of the page. Now to figure out how to get the hilite to reset when you use the back button...

16 Jan 2022-2: After using the web developer tool in Firefox I have discovered that the script is being ignored after the initial use when the page is loaded. I believe this is why it is not working.

16 Jan 2022-1: I have converted the page from a frameset with a separate tabstrip file to a single document with an iframe to contain the target pages and the tabstrip code below the iframe. The JavaScript code still does not work.

For further explanation, I found that the body, iframe and table/link css would not apply from a separate css file, so I put that style information into style tags in the head section and it worked. I left the code for using the stylesheet in the head but commented out. The same was true of the JavaScript code, except that it still doesn't work, even put into script tags in the head section.

I have both versions on my website so anyone reading this can look at them side-by-side to see that they look the same (even though one is frameset and the other iframe), and that the javascript code is not working. Any help figuring out why is greatly appreciated.

Frameset version iFrame version

15 Jan 2022-3: Thanks to sean-7777 for the help. I added his code below and the function works as expected here in the Run Code Snippet. However it does not work in my page. I don't know why. It may be related to the frameset, but only converting that to a div and a iframe will tell me for sure. 15 Jan 2022-2: After experimenting with the web developer tools in Firefox I have determined that the issue is the frameset. Because the tabstrip is in a frame, the javascript in it never gets executed after the first time. Putting the script in the frameset doesn't work because the frame containing the tabstrip never knows what is happening and tabstrip never knows either. I am going to try modifying the frameset to a single document containing the tabstrip and a iframe to contain the other documents when a tab is clicked and see if that cures the problem. 15 Jan 2022-1: I found https://stackoverflow.com/questions/42089472/javascript-change-td-bgcolor-onclick (can't fix the link for some reason) which may actually answer my question, but the petitioner was using an unordered list and I am using a HTML tabstrip generated by Excel (and heavily modified by me). I have used CSS to create a rollover effect and it works flawlessly. But what I lack is a way to have the currently selected tab highlighted. I'm not sure if it can be done solely with CSS or if I have to use JavaScript.

Here is the tabstrip code:

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I am trying to use ImageMagick 7 to detect if a specific channel in an image is largely pure black and pure white (plus a little antialiasing, and there's a chance the image could be pure black). This is to distinguish from another kind of image that shares a naming convention but has photographic-like image data in the r/g/b channels.

(Basically both image types are specular maps from different engines. The one I'm trying to differentiate here is more modern and has the metallic map in the blue channel; the other is much older and just has the specular colour in the RGB channels and the gloss map in the alpha.)

Currently I'm comparing the channel to a clone of itself that has had a 50% threshold applied, using the AE metric to see if it's largely the same apart from a small amount of antialiasing, and a fuzz of 1% to account for occasional aberration from pure black/white. This command works, but of course at the moment it only returns the number of distorted pixels:

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Let's say under one folder main_path, we have multiple pdf files with different amount of pages, I use the function below to loop all files and screenshot each pages:

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How do I convert a svg image to png, save it to a file, and collect basic information about it?

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I'm trying to convert a bat file into a powershell script. But I cannot solve the imagemagick command to determine if the photo is blackwhite.

Can you assist me ? w.

batfile :

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I am trying to achieve the following using a python script:

1. Read in an SVG design file (with images)
2. Manipulate the SVG file
3. Convert this to a web-ready PDF and a print-ready PDF

My problem is with the conversion of the RGB PDF to the CMYK PDF. An SVG with a 15MB photo in it will export as a 15MB RGB PDF, but then convert (using GhostScript) to a 3MB CMYK PDF. When trying ImageMagic, the resolution of the output PDF is determined by the density and I can't find how to keep the PDF's canvas size while setting the density.

So far, I have a script which reads in the SVG files and does some manipulation (add a logo using svgutils, change some text by scanning through the SVG text file). It then uses Inkscape to export the web-ready PDF (using "--export-area-page" and converting the text to paths) and a temporary PDF (using "--export-margin=X" where X is the bleed size, also converting text to paths). The temporary PDF is what I need, except it is RGB rather than CMYK. So, I then want to convert this file (Inkscape does not work with CMYK).

This is the function I am using to convert the file (it is setup with GhostScript and also I was trialling ImageMagick):

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I want to save a table in R as an image that both includes math expressions in the column names and an in-line histogram from the spec_hist() function in kableExtra. Ideally, I would like the table formatted as a Latex table, but HTML would do too.

The problem I have is that when I try to save a kable HTML table, the math expressions are not properly interpreted, but the in-line histogram shows up nicely.

Meanwhile, if I try to save a kable Latex table, the math expressions are interpreted correctly, but the histogram will not appear.

Could this be a bug (two bugs?) in kableExtra? Or am I missing something?

Note that the kable HTML table looks perfectly fine (math expressions and in-line plot) in R Studio/R Markdown. But I want to save an reuse the image. The kable Latex table however never shows the in-line histogram, whether displaying in R or saved to a file.

Here is a reproducible example:

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