I'm doing a sample project on a topic related to Image Recognition where I would like to embed data inside an image, then take a snapshot of the image and retrieve the embeded data from the snapshot image.
Problem Statement: I'm able to embed the data in the image but I'm unable to retrieve the same data from the snapshot image.
Is there a way to adjust the brightness and intensity of colours to introduce a readable signal(data) into the image and retrieve it from a snapshot image?
Example: I would like to achieve what Digimarc Watermarking is currently doing here https://www.digimarc.com/resources/video/how-it-works
It would be great if you guys could provide me any links to do further reseach on solving this issue.
I have a report that renders images (jpg) that have been collected from various sources. This works fine within the report viewer, and when exporting via Excel.
However, when exporting to PDF, about 5% of the images are rendered incorrectly as can be seen below, with the original on the left, and what is rendered on the right;
I find that if I open up one of these images in mspaint, and just click save, on the next report-run the image is now rendered correctly.
Are there any rules as to what image properties/format are valid for SSRS to render the image correctly within a PDF? Essentially I'd like to somehow find these images that will render incorrectly before the report is run and fix them prior...
Current Workaround
I never ended up getting SSRS to display the the problem images as they were, however, determining before running the report which images would be included in the non-displayable set so they could be converted to a supported format (automatically) was also a solution.
In my case, all images were supplied via users uploading to a website, so I was able to identify and convert images as they arrived. For all existing images, I was able to run a script that identified the problem images and convert them.
Identifying problem images
From the thousands of images I had, I was able to determine that the images that wouldn't render correctly had the following properties:
Image had CMYK colorspace or;
Image had extended color profiles or;
Both of the above
Converting an image
I was originally using the standard .NET GDI (System.Drawing) to manipulate images however the API is often prone to crashes (OutOfMemoryException) when dealing with images that have extra data. As such, I switched to using ImageMagick where for each of the identified images I:
Stripped the color profiles and;
Converted to RGB
Note that the conversion to RGB from CMYK without stripping the color profiles was not enough to get all images to render properly.
I ended up just doing those items on every image byte stream I received from users (without first identifying the problem) before saving an uploaded image to disk. After which, I never had the rendering problem again.
Because of the way the output looks I would say those JPEG images have CMYK colorspace but the SSRS assumes they use RGB colorspace and sets the wrong colorspace in PDF.
If you can post a JPEG image and a sample PDF I can give you more details.
I've had exactly the same problem with an image rendering correctly on screen but appearing like the one in the question when I exported the report to PDF. Here's how I solved it.
The Problem
The first clue was this article I came across on MSDN. It seems that regardless of the original image density, the PDF renderer in SSRS resizes all images to 96 DPI. If the original size of the image is larger than the size of the page (or container), then you will get this problem.
The Solution
The solution is to resize the source image such that it will fit on your page. The requires a little calculation depending on your page size and margin settings.
In my case, I'm using A4 paper size, which is 21cm by 29.7cm. However, my left margin is 1.5cm, and my right margin is 0.5cm, for a total inner width of 19cm. I allow an extra 0.5 cm as a margin of error, so I use an inner width of 18.5cm.
21 cm - 1.5 cm - 0.5 cm - 0.5 cm = 18.5 cm
As noted before, the resolution generated by the PDF renderer is 96 DPI (dots per inch). For those of us not in the United States or Republic of Liberia, that's 37.79 DPC (dots per centimetre). So, to get our width:
18.5 cm * 37.79 dpc = 699 pixels
Your result may be different depending on (1) the paper size you are using, and (2) the left and right margins.
As the page is higher than it is wide, we need only resize the width while keeping the image proportional. If you're using a paper size which is wider than it is tall, you'd use the length instead.
So now open the source image in Paint (or your image editor of choice), and proportionally resize the image to the desired width (or length) in pixels, save it, import it into your container, and size the image visually with respect to the container. It should look the same on screen, and now render correctly to PDF.
This is an issue reported to Microsoft Connect.
From SSRS 2008 How to get the best image quality possible?:
The image behavior you see in PDF is a result of some image conversions that the PDF renderer does, based on how the PDF specification requires that serialize images into PDF.
We know it's not ideal, and we classify the loss of image quality as a product issue. Therefore, it's difficult to really say what to do to get the best quality image.
Anecdotally, I have heard that customers have good results when the original image is a BMP
this question is in close relation to Firefox 3.5 color correction hack?
The situation I have is that there's a canvas game of mine, and the images that are used in it carry additional information about their shape, connection points etc. This information is stored in the PNG image itself, using meaningful colours (eg RGB(255,255,0) for connection point).
Loading element and painting on the canvas creates Image object, img.src is set, and in img.load function I preprocess image data reading the sensitive information (and removing sensitive pixels from the image data before painting to canvas).
The problem: In FF, the pixel which was supposed to be 255,255,0 is actually 255,254,0. I don't have problems with FF color correction (I don't care if the displayed image has right colors, or slightly modified), but I'd expect that getting image data gives me uncorrected data. I'm looking for a solution which would not involve changing images on the server. Is there some way? Eg.
img.setColorProfile(), or
img.disableColorCorrection(), or
img.getImageData(disableColorCorrection) or img.getImageData(colorProfile)?
The problem might have do more with image loading than image drawing.
I think the proper solution is to strip out color profile information from the images (which you seem to want to aovid). If possible server another image resources for Firefox if you cannot need to have the original data intact.
http://f6design.com/journal/2006/12/01/fixing-png-gamma/
Also, you could decode PNG immages in pure Javascript if the server is co-operate and allows CORS and AJAX loading of the images. You decode the image in Javascript using png.js and create a source <canvas> from the image data (instead of <img>). This way it's you in the control what RGB values comes out from each PNG pixel.
https://github.com/devongovett/png.js
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I have a application to show some videos and images.. like a presentation.. The images have different resolution's and the videos to. I want to put the images and the videos in full screen mode but without lose quality.. The rotation of screen is fine, but the media content does not appear like they should..
Basically i want to show the images centered in vertical and horizontal without lose quality..
Suggestions?
For the video I would recommend using a MediaElement with the Stretch attribute set to 'Uniform'. 'Uniform' takes up all the space that you give the control but it ensures that the video maintains its aspect ratio. You should still have all the qaulity possible because the stretching happens on the GPU and it does a great job. You can see an example here:
http://msdn.microsoft.com/en-us/library/system.windows.controls.mediaelement.aspx
Now, if you want the video to only scale up to it's orignial size but not get blown up any larger, then just set the Stretch property to 'None'.
The Image control works the same way and also has the same Stretch property. See the Image class documentation and sample here:
http://msdn.microsoft.com/en-us/library/system.windows.controls.image(v=VS.95).aspx
Did you try the MediaElement API and the NaturalVideoHeight and NaturalVideoWidth properties?
I'm looking for a service such as placekitten dot com that also includes the dimensions in the image. For example, a 200x300 kitty image would have "200x300" as 'text' overlaying the picture.
Are there any other services doing this?
http://placehold.it/ shows dimensions on a generated image, but it does not have a (cute) picture behind.