Why when adding a pic for watermark, always cover the detail background color?
I have tried with another type file. But it still same result. Anyone can help me?
Crystal-Report with example watermark
Crystal Reports doesn't have very good support for the transparent layer background of most image file formats. In almost all cases, images files are converted to a Bitmap image when they are used in a Crystal Report. This causes images to have a background that is slightly off compared to the color of the reports background. Underlay and moving the image behind other objects on the report help with most issues for the report's design, but you can never place the image behind the background.
There is a workaround for this using WMF or EMF files though. These are two image file formats that work in Crystal Report and support transparent layer backgrounds. If you don't have photo editing software that can produce WMF or EMF file, then there are two ways to do this without buying additional software. The first option is MS PowerPoint. If you insert the image into a PowerPoint presentation, then right click the inserted image, you can then choose Save As Picture and WMF and EMF are both available file types for this. The second option is a website called Zamzar. This website will allow you to convert files from one file type to another. Its a fairly fast service, but they have file size limits for free users.
Always keep in mind that the image will need to have a transparent background in the original file format before converting it to a WMF or EMF file. Also bear in mind that converting files from one type to another can sometimes have unintended implications upon the quality and detail of the images. Sometimes the best way to get a good quality image is to seek out the graphic designer who produced the image and request they provide the image in the WMF or EMF file types.
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In ghostscript-crop-pdf-not-correctly,I got a cropped PDF,but it's only seemingly cropped.The remaining content still exists in fact.
In ghostscript-removes-content-outside-the-crop-box or
how-to-truly-crop-a-pdf-file or pdf-real-cropping or cropping-a-pdf-using-ghostscript-9-01 or itext-crop-out-a-part-of-pdf-file, no solution was found.May be a virtual PDF printer is the only way.
Use ghostscript or itext, Is there any way to clip a PDF file really.
A very straightforward (but perhaps not the most intelligent) way of solving your problem is to use pdfSweep.
pdfSweep is an iText7 addon that allows you to redact (remove) content.
It allows you to remove content by:
specifying a regular expression
specifying a rectangle (or rectangles)
In your case, you could calculate the rectangles you want removed, and then apply pdfSweep.
If you then crop the remaining page, the content would really be gone.
More information (including code samples) can be found here.
What leads you to believe that the content is still present ?
Any object which is not at least partially contained within the page clip will not be forwarded on to the pdfwrite device by Ghostscript, so I'm doubtful that content is preserved.
Your original question related to cropping away white space, so that makes your example file less than useful in this case. You should post an example of the problem file, and the Ghostscript command line you have used.
Note that if you are trying to crop out an image then no, this won't do what you want. If any part of the image lies on the media, then the entire image will be included in the file. The pdfwrite device isn't equipped to extract sub-areas from images. This is true for all the PDF editors that I'm aware of.
I created some presentation with a lot of small images.
The problem is - that those images were originally whole screenshots (1920x1080 px), which I used Impress' image cropping tool to take only small relevant parts of the screenshot.
If you ask why is it a problem -> the answer is that instead of containing ~30 very little image crops, my presentation contains ~30 1920x1080 sized images, and just shows them according to the current crop settings.
It causes the saving process to take ~10 seconds, the output file is very large and everything works slowly because of the complex rendering process.
Is there any way to discard the cropped parts of the images?
The cropping tool is not good for making such large changes. From https://wiki.openoffice.org/wiki/Documentation/OOo3_User_Guides/Writer_Guide/Cropping_resizing_rotating (and this is true in Impress as well):
If you crop an image in Writer, the picture itself is not changed. If
you export the document to HTML, the original image is exported, not
the cropped image.
Instead, use separate image software to do the cropping before putting the images into Impress. I typically use IrfanView.
For a discussion see https://forum.openoffice.org/en/forum/viewtopic.php?t=3665.
I have to work with image which is coming from some server. We want to process that image so that we can find out does it contain any specific color region.
Is there any way so that the image coming from server will be overlaid image & on device side we can process it to check if it contains those overlays?
I have never being worked on quartz stuff. If anybody can suggest some other solution?
There are several ways to do this depending on how complex you wish to get. OpenCV has image blocking which can segregate images into distinct regions. Or check out Image tools especially blob extraction and then look at the general pixel colouration in a single blob.
I want to remove watermark from a picture within my iPhone / iPad application. Is there any kind of image processing I can perform within this application to do this?
Can't be done, sorry.
The watermarked image were originally two images (the base and the watermark), which were merged together to form the result. The problem here is that the most common image formats (such as JPG, PNG, or GIF) have no concept of layers - so that the base would be one layer, and the watermark another: the result is just one layer, onto which both were redrawn. This is somewhat similar to a physical painting: if you paint one image on a paper using watercolors, and then another over the same spot, their colors will mix and you won't be able to tell which parts belong to one or the other, as they'd become a single image.
This is similar with the computer image formats: there is only one "layer", which for every pixel encodes exactly one color that is there - only the current color exists, and the image doesn't keep track what was on that pixel before.
Now, the information is irreversibly lost from the result - in other words, it is not possible to recover the base knowing just the result (or the result and watermark) - BTW, that's exactly the point of watermarking.
I have borrowed the image sprites of StackOverflow for a demonstration; the actual images used are not unique, the technique would work just as well with any images. This was the watermark I used:
And this is the result image, after merging with the base:
Now, even though we have the exact watermark image used, there's no way to recover what was underneath that star in the original image. Through image processing operations, we could almost remove the star from the result, but there's not enough data to tell us what used to be underneath: - that information got erased in the merge at the beginning.
We could guess what used to be there, but then we're not doing recovery any more, we're interpreting the image and guessing what possibly could have been there - and that's pretty hard, even for a human; computers are really bad at that. This is the original image, before I watermarked it - I bet you were expecting something slightly different, no?
The watermark is almost certainly part of the image. (The only case in which it wouldn't be is something like PDF or SVG, where it could be a separate vector element.)
Watermarks are typically present on images for purposes of managing intellectual property; if one has licensed an image for a particular use, typically one will receive access to a version of the image without a watermark. Thus wanting to "remove watermarks" is also likely to be treated as highly suspicious.
Watermarks are part of the image, there isn't going to be a magic way to remove them and recover the missing pixels in any tool.
Take a look at the source! Most or the current watermarking is done in php as an automated script. In most cases you will see the base picture in source
I’ve been busy working on the graphics for my iPhone application. I started working on generating icons for my UITabBar and ran into lots of problems. How do you create these icons?
I created this solution:
http://www.nailrails.com/?p=46
Are there any shortcomings to this approach? It seemed to work for the few icons I created...
Apple's guidelines can be found at http://developer.apple.com/library/ios/#documentation/UserExperience/Conceptual/MobileHIG/IconsImages/IconsImages.html#//apple_ref/doc/uid/TP40006556-CH14-SW1
The docs are pretty straightforward-- alpha is all that matters when the image gets loaded by the toolbar, meaning that anything that's not at least semitransparent will render in the same opaque shade. As for how I do that, I mainly use Adobe tools. Fireworks is my preferred tool but Photoshop's also more than up to it. Another one I've had good results with is Acorn, which is frankly a lot cheaper while being more than sophisticated enough for this kind of work. I'm not really a graphic designer but a certain familiarity with this kind of stuff goes with the job.
I have an article up on my site that shows how to use OmniGraffle with a template I use to create great iPhone toolbar icons in minutes:
http://steveweller.com/articles/toolbar-icons/
The template sets up a grid to work to that corresponds to one square for each pixel. You draw your icon in white on top of the black template background and then export as a PDF exactly the right area to match the icon size you need (typically 21 pixels high). Then you reimport the PDF, resize it to the final icon size (21 pixels again), and export as PNG. The template does nothing magical; it just provides an already set up working area and helps you get the final PNG right every time to the scale is correct.
You could use the same technique in Acorn or any other app that supports PDF export and layers.
(I use Gimp. Assume your icon layer already has alpha channel.)
Right click the layer, then add layer mask.
Done with option "transfer alpha channel of layer" chosen.
Select the whole layer (but not layer mask), and clear it with pure white.
Resize image to Apple-suggested size, and export it as png file.
You may also paint directly on the layer mask.