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)
Related
I am using power autoamte to convert an image in base64, and then I put this code in html.
Here is what I do:
I convert the original image to base64
I put this code in the html content in the <img src='myBase64'>
tag.
I convert the html to pdf format
Everything is fine, but when my html file reaches more than 2 mb my flow stops working. This is the limit for this conversion operation.
My question is:
Is it possible to resize the base64 code? I know there are external connectors resize images like Encodian, but I don't want to use them.
I searched on the internet, but without much results.
Thank you in advance
I'm trying to create a small PDF file, embedding one optimized PNG image displayed as a header and footer on a 3 page PDF (same image must appear 6x in the PDF)
My optimized PNG image is only 2.3KB. It looks very sharp.
Failed with libreoffice
When I insert just one instance of the 2.3KB PNG image into a Libreoffice Writer doc containing only text, then export as PDF I can see that the image gets re-compressed to JPG and the resulting PDF file grows by about 40KB after adding the image. It also loses quality, the PNG also gets JPG fuzzy edges.
If I right click the image and select compression, there is no way to disable recompressing the image (it's already optimized better than libreoffice could do it) I've tried setting a compression level of 0,1,9 etc. Choosing JPG, no resize, lossless, etc but there was no improvement.
Failed with wkhtmltopdf
I also tried making a test page and used wkhtml2pdf but it did the same thing. Adding the low quality flag made no difference.
PDF Spec suggests PNG is supported?
From skimming the PDF spec, it looks like PNG images are supported.
Even plain text PDF files are surprisingly large
The disappointing thing is also when I take a 7KB HTML file which is basically just <html><body><p>foo...</p><p>bar...</p> (only about 15 paragraphs) with no CSS. The resulting 2 page PDF file is 30KB. Why should a 7kb (almost plain text) file become 30kb as a PDF?
Suggestions?
Can someone please suggest how to make a small PDF file in Linux?
I need to include 7KB of text and repeat one PNG image 6 times.
Manually or programatically. I'll take whatever I can get at this point.
PDF Spec suggests PNG is supported?
PNG isn't supported per se; PDF allows embedding JPEG images as-is, but not PNG images. PDF does borrow a set of features of the PNG format, however.
rinohtype (full disclosure: I'm the author) tries to embed as much as possible from PNG images as-is into the PDF. This does involve some bit-juggling to separate the alpha channel from the color data for example, but no reencoding of the image is performed. It does not (yet) support interlaced PNGs.
rinohtype should be able to do what you want to achieve. But please note that it currently is in a beta stage, so you might encounter some bugs.
Even plain text PDF files are surprisingly large
To keep the PDF size as small as possible, make sure not to embed/subset any of the fonts. Use only the fonts from the base 14 PDF fonts which are provided by PDF readers.
What you want is certainly achievable. Regarding the image quality, I would recommend making your image twice the size that you want it to actually display at in the PDF to keep it looking sharp.
As to the size, I've just modified a test in my PDF writer module (WIP..) to include a 7.2K png, 200px x 70px, in a PDF twice and the PDF came out at 6.8K 8). There's not much text included, but more text will only add what it's worth + a small percentage.
You can see the module and original test here.. https://github.com/DoccaPDF/docca-pdf-writer/blob/master/src/tests/writer.js#L40
That test adds ~112K of images to the PDF and results in a 103K PDF.
Of course not all images are created equal so you milage may vary..
*the images are only actually added to the PDF once, but are displayed multiple time.
I'm working on a photo viewer. In this context, I wrote a small class to be able to read and use some EXIF data, as e.g. image orientation. This class works well for reading.
However, I would add a new option to rotate photos. I want to rotate and write the photo data itself, not just rewrite the orientation tag. I already wrote the code to rotate and save the primary JPEG image, and it works well. But I also need to rotate the thumbnail contained in the EXIF data, if any, to keep the image coherent. For this reason I need to write in the EXIF data, to replace the existing thumbnail.
But this raises some questions, that I've some trouble answering, namely:
Can the EXIF data contains more than 1 thumbnail, and if yes, what is the maximum thumbnail count that an image can contain?
What are the supported formats for thumbnails? (I found JPEG and TIFF, are there other?)
Is there any guarantee in the EXIF standards that the thumbnails are always written in the late EXIF data, just before the primary image?
If not, then each tags containing an offset that points to a location beyond the thumbnail to replace should be updated. So, is there a standard way to iterate through all tags and sub-directories, to recognize which EXIF tags contain offsets, and to update them if needed? Or the only way is to read a maximum of tags and rewrite only that are known?
Or is there a way to guarantee that the size of the newly rotated thumbnail will be smaller or equal to previous thumbnail size to replace with?
Regards
Here are some answers for your questions:
1) The EXIF data is laid out like a TIFF file with 2 pages. The first page is the camera information and the second page is the thumbnail. If you add more pages (with thumbnails), 99.99% of the applications probably won't notice since you'll be doing it differently than the "standard" way. As far as "maximum count", you have 64k of data that can be stored in any JFIF tag. You can put what you want in that 64k.
2) There is only 1 supported EXIF thumbnail format: TIFF. Inside the TIFF there can be compressed (JPEG) or uncompressed data. Again, you're welcome to stick LZW-compressed data in there, but most apps probably won't be prepared to display it properly.
3) The JFIF container format allows for tags with metadata to appear before the main image. The APPx tags contain metadata that can follow the standard or not. You're welcome to stick multiple EXIF APP1 tags into your files, but again, most apps won't be able to properly handle that situation. So the simple answer is that the EXIF data (including thumbnail) must come before the main image and if you put more than 1 thumbnail it will most likely be ignored.
4) If you are modifying a JFIF (including the metadata), you must rewrite the metadata. It's actually quite simple because each tag is independent and has a simple length value instead of relative offsets.
5) You can do anything you want with the size/orientation of your thumbnail as long as you make the EXIF APP1 tag data total size fit within 64k.
Here's what you need to do...
1) Read the source image (and thumbnail if present).
2) Prepare your rotated image (and thumbnail).
3) Write the new metadata with the new thumbnail image.
4) Write the new main image.
If you want to preserve the original metadata along with your new thumbnail, it's pretty easy. Just read the original tags and hold on to them, then write them in the new image. Each JFIF tag is just a 2 byte identifier (FFxx) followed by a 2 byte length and then the data. They can be packed in almost any order and there's no hard limit on how many total tags can appear before the main image.
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
I am using TCPDF to create PDF files converted from HTML input using it's writeHTML() function. However, images within the PDF have poor quality, while the original images have a high quality (as expected). The images are in PNG format. I already tried to use SetJPEGQuality(100), but that had no effect.
What is causing this?
Try using this:
$pdf->setImageScale(1.53);
http://sourceforge.net/projects/tcpdf/forums/forum/435311/topic/4831671
When using HTML to generate your PDFs you need to manually calculate the images dimensions by dividing it's original width and height by 1.53 and set the result as attributes.
For example, an image with dimensions of 200x100 pixels will become:
<img src="image.jpg" width="131" height="65" />
This is a nasty workaround and doesn't completely remove the blur, but the result is much better than without any scaling.
Try To convert your Image to JPG or JPEG first. Until Now, I DOnt have a problem to convert image with TCPDF. I Think TCPDF is powerfull, because it can convert arabic language too. I HAve try convert arabic font with fpdf n it still fail
Little Up.
I'd same quality problem and I solved it...
When you save your picture, do it in 8bits instead of 24bits and you will see a "beautiful anti-aliasing".