I'm working on a Raphael project that draws vector graphics with repeating PNG fill elements. To minimise file requests and maintainence, I'm storing these PNGs as base 64 strings in the JS. IE8 needs to be supported, sadly.
On SVG, this works fine. In VML on IE8, it doesn't work, despite the fact that a) VML supports image fills and b) IE8 supports base 64 images.
Is there any way I can get my PNG data into my VML without needing to upload actual PNG files?
Here's an example of how the string that is passed to Raphael's .attr('fill'); is being defined:
"url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAADpJREFUeNpi/P//PwMMnDp1whRI8bMwoAIxIHZgPHnyOLKgBBD/BqkEawHiPUD8AiTDBNXijqwcIMAANW4Lseujok0AAAAASUVORK5CYII=)"
Same problem with single quotes inside the url():
"url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAADpJREFUeNpi/P//PwMMnDp1whRI8bMwoAIxIHZgPHnyOLKgBBD/BqkEawHiPUD8AiTDBNXijqwcIMAANW4Lseujok0AAAAASUVORK5CYII=')"
Debugging VML is always a nightmare, but using the trick here and hacking my way to the VML shape's outerHTML property, I can see that the above is being applied to the fill element's src property:
<rvml:fill class=rvml firebug-1432221487827="1566" rotate = "t" src = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAEJJREFUeNpiPHnyOAMUZANxPRA/ZGFAAFkgFgVhkGAcEPMDMRsQ7wTiHyDBhVCVE4DYA8RgAuLXQPwNiF/CzAEIMABgqgriagn8AQAAAABJRU5ErkJggg==" type = "tile" position = "13861519f,3859415f"></rvml:fill>
Related
I’ve been using the PDFConverter for years with no issues. And there are still no issues converting a large HTML form to PDF, except certain images aren’t showing.
I programmatically fill an HTML img element with a base64 string, like so:
imgSignature.Src = "data:image/jpg;base64," + Convert.ToBase64String(SignatureImage);
where SignatureImage is a byte[] array.
I've observed that if the byte[] array size is more than around 7K (not sure exactly the threshold), the image will not render to PDF (at least it’s not visible anyway). Anything under that displays fine. Note: the image displays in HTML just fine. It's when converting to PDF that it disappears if the byte array is too large
I've tried adjust the size of the img, the container it's in, everything I can think of.
Currently still going through Winnovative support docs but no luck so far.
Thanks for any advice.
Just in my case, I changed all images formats from jpeg to png, and it works for me. It's worth mentioning that my images are between 6kb to 8 kb (the images are Bar Codes)
I've noticed this strange "bug" on my website. Sometimes some svgs aren't loaded correctly. Some images are loaded just fine, some svgs get loaded but not fully. (some parts aren't shown)
Here are examples:
Loaded fully, working fine - https://i.imgur.com/IsZcqwl.png
After closing page and opening it up for few times - https://i.imgur.com/3ManRbR.png
Actual SVG image - https://www.dropbox.com/s/i1ln1a0diko0a12/parrothandshake.svg?dl=0
You svg image: is a base64 converted png.
You can see it in the tag attribute here: xlink:href="data:img/png;base64,iVB[...]
I would not recommend using base64 at all. Even more so in a image tag inside an svg image. (This is debatable and opinion based)
I would recomend using Inkscape to convert png images to svg. There is a build in function for converting in the editor. Its also free and a handy tool to have when working with svg images.
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
Here is an image:
This image is a simple black-to-transparent gradient saved in full RGBA PNG.
Here is the same image, converted to indexed-alpha PNG by GIMP (Photoshop produces the same result)
As you can see, the gradient is now half-opaque, half-transparent.
Here is the same image again, only this time it was converted to indexed-alpha PNG by a PHP script I wrote:
So my question is: Why are GIMP and Photoshop unable to support partial transparency in indexed images, when the PHP script clearly shows that such an image can be created with no problems?
Is there anything "wrong" with an image whose pallette contains alpha information?
A more programming-related question: Does this transparency in the last image work in Internet Explorer 6?
I've finally found the actual answer: There is a metadata entry that allows you to define the alpha value of each colour in the colour table. Most graphics programs don't make use of this, but it does exist and can be used, in particular by GD.
Another option besides fireworks is pngquant, a command line application that will convert a rgba png into an indexed png with transparency.
I found this post which talks some more about how to use it.
IE6 and earlier in windows does not support variable transparency PNGs without annoying workarounds. An indexed PNG will only show the fully opaque parts which usually works pretty well. A drop shadow would disappear but the opaque parts of the logo or icon would continue to show.
This page has a better explanation and instructions with more png compression and quantization tools: http://calendar.perfplanet.com/2010/png-that-works/
For the record, PNG does not literally support indexed images with an alpha channel. What is really happening is that PNG allows you to add additional colors to the color table (i.e. index) with alpha values in those colors... not a complete alpha channel. FWIW...
Yeah I know what you mean. Fireworks is the only image editing program that I know of that can create and edit PNG8+Alpha without problems. I wish more paint programs would support this format cause Fireworks is expensive!
I found a way in GIMP to create or convert an image with reduced color palette and alpha channel.
The trick is to add a mask to the layer.
Full steps to reproduce:
Have your image in one layer
Add a mask to the layer. Select Transfer layer's alpha channel.
Convert to Indexed (Image -> Mode -> Indexed...)
Save as PNG
Now your image has reduced colors and reduced size, but it keeps your smooth transparency.