Poor image rendering with Google Docs PDF viewer

Question

I used Word 2007 to create a PDF file with a 1526px * 900px image filling the entire page. This is not the first time this has happened, but Google Docs PDF Viewer absolutely controls the color rendering, which makes it unusable.

I took screenshots at the same zoom level in the Google Docs viewer and Foxit Reader.

Here is the image to compare:

It's horrible! I tried to communicate with some things, but I can not find anything that could fix this problem.

Answer 1

Let it be written here, 16 months after the original Turkeyphant original publication and a similar publication [1] on the Docs + Drive product forum, that the problem seems to have been fixed in the past week. From the time a PDF (or Word) file is opened, which is located in the Docs + Drive cloud, the file is displayed with the corresponding 24-bit color. Processing in which the color was reduced to 5 bits, which could encode 32 colors or 32 shades of gray or 16 of each, depending on the image, was left.

As far as I know, Docs + Drive employees have not announced this change either on their blog or on their product forum. I noticed the changes a few days ago and noted this in the conversation [1].

[1] (2013-05-21) Problem in pdf-viewer with color images https://productforums.google.com/d/msg/docs/_bdfiYgjF2s/5PDMdp9MhFQJ

Answer 2

If you use Chrome, you can select "Print", and then in the next dialog box, select "Save as PDF." The quality of the image in the saved PDF document will improve significantly compared to the quality of "Download as PDF". Google seems to be optimizing images to conserve bandwidth.

Answer 3

This may have something to do with image compression in PDF.

I mean that PDF supports JPEG2000-encoded images ( JPXDecode Filter) and in the PDF Reference:

From one JPEG2000 data stream, multiple versions of an image can be decoded. These different versions form a progression in four degrees of freedom: sample resolution, color depth , range and location. For example, with the progression of resolution, the thumbnail version of the image can be decoded from the data, followed by a sequence of other versions of the image, each of which contains approximately four several times (two times the width twice), since the Previous one. The latest version is a full resolution image.

The Google Document Viewer can only display the first version of an image (with a lower resolution or lower color depth), which creates a "terrible" output.

Answer 4

Perhaps an attached pair of images will help clarify what happens to the color in the images that are displayed through the Google Docs document viewer. I inserted the Wikipedia image RGB_Color_Solid_Cube (1024 * 1024 pixels) into an empty Google Docs document, converted it to pdf and looked at the received PDF files in two ways: once through Google Docs + Drive pdf viewer and once through regular pdf viewing a Chrome or Firefox browser . Then I took screenshots. Here is the RGB Color Cube through the Docs PDF Viewer , and here is the RGB Color Cube through the regular PDF Viewer browser .

The color resolution in the Docs PDF Viewer version is really awful; It looks like 64 colors at best. Perhaps someone else will be able to recognize this type of rendering and better identify the problem.

Answer 5

This is due to compression, and this is something you cannot change in the default view for Google Docs Viewer. A simple solution is to download the PDF file and simply maintain it from the site in iFrame. Here is an example:

Issue Embedding a Google Docs PDF

Mike