How to clip/crop an image with AsciiDoctor - asciidoctor

Is there some way (besides writing a plugin) to clip/crop an image which is inserted into an AsciiDoc document?
I couldn't find such a feature in the docs but there might be a plugin I am not aware of...

No, there is no such feature. When you use the image: macro, you can set the image's width and height, but there is no option to set the crop area or starting point for cropping. See https://asciidoctor.org/docs/user-manual/#images for details.
To crop the images, you might need to perform some sort of pre/post processing to directly crop the images. Unless you have a requirement to dynamically crop the image, it's probably best to do so manually.
If you do need the ability to dynamically crop images, you might create a plugin that creates a new macro, say crop:, that uses the image: macro's internals, but accepts crop coordinates and performs the cropping on the source image.

Related

Resizing a canvas to the size of a pasted-in image when the pasted-in image is larger than the canvas

First, I know this is a terrible workflow; it's being enforced on me by my employer's SDL Tridion Docs content management system, which seems to specialize in showing complete contempt for its users.
I need to open a raster image in Gimp, paste in a new image, resize the canvas, save and close. This works fine when the pasted-in image is smaller than the original image, but when the pasted-in image is larger I cannot for the life of me find a function to detect the size of the pasted-in image and expand the canvas to fit; all of the functionality seems to assume that the new image will be smaller. I'm looking for the equivalent of the "resize document to selection" command found in Inkscape.
If you do this manually, see Image>Fit canvas to layers.
If you do it in a script, pdb.gimp_image_resize_to_layers(image) in python, something similar in Script-fu.

change dicom image's window width and window level

Recently, I am working on process dicom image怂I don't know how to change the WWWL of a dicom image. Also, I use dcmtk to convert dicom image to bmp and show it(I didn't use vtk to show the image). I really don't know if that is correct.
I want to know the algorithm which can help me change the dicom image's window width and window level automatically. I didn't find the corresponding algorithm while I was using dcmtk.
thanks and regards.
If you want to specify the values of Window Center and Width (aka VOI transformation or windowing) manually, you can use DicomImage::setWindow() for this purpose. If you want to specify an automatically computed min-max window, you could use DicomImage::setMinMaxWindow().

How to display a .bmp in an NSImageView for MacOs so that a certain color is transparent?

I have some .bmp files that have some color (maybe black) that is supposed to show as transparent when the graphic is displayed on top a form, so the form color comes through the transparent areas. But by default, when I put these images in an Image View, the black/transparent areas show up as BLACK!
I'm thinking I need to either:
- alter how the NSImageView shows the image, so that a certain color is transparent, or
- modify the .bmp files somehow to make that color suitable for transparency in an NSImageView
But I don't know enough about graphics files, transparency(alpha), NSImageView, nor the image editing tools. I'm trying to use Gimp, but...not sure what I'm doing yet. It seems like there is already a color that should be transparent in the current .bmp file.
I'm sure its something simple for setting NSImageView, or editing my file, or perhaps making a mask for the image, but I don't know how yet. I've looked at various filters in IB for NSImageView, but have not found where to set the transparent color, nor how to grab that color from the image file to make sure I use the correct value.
Thanks in advance for any assistance. (I tried to post some images, but because I'm new, I could not.)
Beau
I'm not a Cocoa developer, but in Gimp try adding an alpha channel to your image (a layer mask, perhaps) then saving as a 32-bit PNG image (with an alpha channel), then load that PNG directly into your NSImageView. If you want to make the black pixels transparent in Gimp use the magic-wand tool to select them (use magic-wand with 0 tolerance) and just delete the contents of the selection then save as a PNG directly.

How to make thumbnail images for custom Liferay Layouts?

How to make thumbnail images for custom Liferay Layouts? If anyone has done it using any open-source software, please help!
In Liferay 6.1 source folder /liferay-portal-src-6.1.0-ce-ga1/portal-web/docroot/layouttpl there is a zip file called thumbnails.zip which in turn contains thumbnails.psd, which contains thumbnail images for all the bundled layout templates. As for an open-source image image editing software, there is Gimp. Unfortunately, I didn't have much luck opening the mentioned file with it - the glossy overlay lost it alpha value and the large background rectangles seemingly lost their gradients and are all solidly colored. You could try Paint.net as well, which also stands in high regard among free image editing software.
The latest version of liferay docs containing any mention of layout templates thumbnails are for Liferay 6.0 series and you can find it here. There is also an empty png layout thumbnail template with proper background gradient, but you would have to make your own gloss over the little light rectangles as well as make the corners round...
All in all, you could also try to make the thumbnails from scratch, give them a more unique look. The image from Liferay docs should give you the idea of what it should like to still look nice next to bundled layouts' thumbnails. I'd just suggest to try and use vector image editing software. The bundled thumbnails all look simple enough to draw them with vectors, which would give you more flexibility and ability to change your mind anytime about details without having to draw everything all over again.
And that's for a 121x121 px image...

how to make a Sprite

ive used an online srpite service http://spritegen.website-performance.org/ but i want to know how to make them by myself.
How can i save an image that it should be so small but when used on my web site it comes out normal size?
Sprites aren't about making the image itself small, it's about decreasing filesize by packing several images into one.
Take a look at Yahoo's icon sprite. Notice that they have all their section icons stacked vertically in one large image. They then use CSS to position the background to only show a small window of the sprite image, thus giving you just the icon.
In the end, it's up to you how you arrange your sprite. Check out the bottom of Amazon's sprite.
Either way, hopefully that helps gives you a better idea of the concept of sprites.
From the very site you link:
CSS sprites are a way to reduce the
number of HTTP requests made for image
resources referenced by your site.
Images are combined into one larger
image at defined X and Y coorindates.
Having assigned this generated image
to relevant page elements the
background-position CSS property can
then be used to shift the visible area
to the required component image.
So there is nothing magical involved: you simply need to pack all your pictures into a single giant image with your favourite graphics tool and insert them as CSS background. Just look at this CSS sprite by Google:

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