How to Deskew the PDF Pages

PDF Document Management 7: Deskew PDF Pages

PDFill PDF Deskew provides a quick way to correct the skew in the scanned images from Acrobat PDF documents. In this process, the original PDF page is inserted into a new blank PDF page. So, you can change the new page size. You can rotate, transform, scale, or crop the PDF page just like the way as you work on an image.

There are two ways to Deskew PDF Page:

1) Deskew Current Page Automatically: The function detects the tilted image and rotates it automatically using a special algorithm. It works only with the scanned text-print image.

2) Draw a line to Deskew Current Page: You can deskew semi-automatically by drawing a line. This requires visual work but it is more accurate and it can provides tune-up to the first automatic method.

Here are the steps on how to deskew PDF Page automatically:

1. Choose Document Menu > Page Deskew > Select Page to Deskew

or click Select Page to Deskew Button in the Document Toolbar.

2. The Deskew PDF Pages dialog box comes up:

Specify the range of pages to deskew: Current Page, the page ranges or pages in the example format of "1, 3-5, even, odd".

Deskew using Automatic Angle Detection: It automatically checks if the PDF page is skewed, then corrects the skewed PDF page using a special algorithm. It works only with the scanned text-print image.

Deskew Angle Range: Specify the working (deskew) range in degrees. Low values enhance performance. For example, specifying 30 Skew will scan the image searching for pixels inside a range of -15 to 15 degrees. Angle Range can be from 1 to 90. The default is 30.

Deskew Sampling Skip: Sampling skip means that only a fraction of the submitted lots are inspected. This mode of sampling is of the cost-saving variety in terms of time and effort. The range can be from 0 to 20. The default is 0. The lower Skip, the higher accuracy but slow speed.

Deskew Page DPI: The image DPI that the PDF Page is converted into Image so that PDFill detect the Deskew Angle. The higher DPI, the higher accuracy but slow speed.

3. Click OK to deskew. The new PDF page will be displayed inside PDFill like a PDFill Image Object:

You can rotate, transform, scale, or crop the PDF page just like the way that you work on an image.

Double click this object to see Deskewed PDF Page's Properties:

Position (Left, Right, Width, Height)
The X and Y coordinate of the box to define the position of the object.

Scale The image scale inside PDF.

Lock aspect ratio The ratio of width and height will be kept as you change the size of image.

Relative to Original Size The original width and height will be used.

Rotate The rotation degree from 3 clock relative to the image center.

4. Add PDF Objects and save into a new PDF.

Before

After

Here are the steps on how to deskew PDF Page by drawing a line:

Draw a line to Deskew Current Page: You can deskew semi-automatically by drawing a line. This requires visual work but it is more accurate and it can provides tune-up to the automatic method:

Choose Document Menu > Page Deskew > Select Page to Deskew
Try to maximize the PDFill PDF Editor's Window if possible.
Zoom the PDF Page so that one text line will be see clearly.
Choose Document Menu > Page Deskew > Draw a line to Deskew Current Page, the mouse icon will become cross.
Hold down the left mouse button. Click the first point along this text line's base line. Don't release the left mouse button.
Move the mouse button to the second point on the other side of the text line's base line. Release the mouse button.

PDFill will calculate the slope of the line and adjust the deskewed PDF Page.

Position (Left, Right, Width, Height)	The X and Y coordinate of the box to define the position of the object.
Scale	The image scale inside PDF.
Lock aspect ratio	The ratio of width and height will be kept as you change the size of image.
Relative to Original Size	The original width and height will be used.
Rotate	The rotation degree from 3 clock relative to the image center.