GDI+ PictureBox - DPI Blurry Output

[technipixel]

Hello,

I am developing a Ticket Printing application in VB.NET
The issue I am having is that my "ticket artwork" is pixel perfect, but when outputting to PDF... the quality is bad.

Here is my apps program flow...

- Load (dialog box) a ticket image (created at 280w x 123h pixels) into PictureBox (i.e. imgScrn)
- The actual image looks great before bringing into app (#3 on screenshot below)
- Then using the Paint event of the picture box, I paint the 2 Ticket Numbers on top using e.graphics (GDI+)
- I do use "g1.SmoothingMode = SmoothingMode.AntiAlias" for the Numbers.
- The actual ticket image doesn't look bad on the screen (#1 on screenshot below)

However, look at the PDF output.... everything looks bad. (#2 on screenshot below)
I am thinking that the images and numbers outputted on the PDF are actually larger then the original... thus jaggies.

Code-wise....
- I am using Pts for for text and measurements.
- My PDF page size is 612x792... this gives me a letter sized page

I am not sure if I have my DPI set properly or at all.

 Private Sub mnuPrint_Click(sender As Object, e As EventArgs) Handles mnuPrint.Click

        'set general variables
        Dim iLF As Integer = 26  'left margin
        Dim iTP As Integer = 27  'top margin
        Dim iCTR As Integer = 306  'top margin
        Dim imgW As Integer = 280  'img width
        Dim imgH As Integer = 123  'img height
        Dim cutL As Integer = 15  'cutline left
        Dim cutR As Integer = 597  'cutline right

        'Create a New instance of PdfDocument.
        Dim pdfDoc = New Syncfusion.Pdf.PdfDocument()

        'Change page size
        pdfDoc.PageSettings = New Syncfusion.Pdf.PdfPageSettings(New SizeF(612, 792))

        'Add a New page to the document
        Dim pdfPageX = pdfDoc.Pages.Add()
        Dim pdfGraphicsX = pdfPageX.Graphics

        'add page border
        Dim cutBorder = New RectangleF(iLF, iTP, 560, 738)
        Dim pdfPen = New PdfPen(PdfBrushes.Silver, 1.0F)
        Dim pdfBrushX = PdfBrushes.White

        'Draw rectangle using PdfPen And PdfBrush.
        pdfGraphicsX.DrawRectangle(pdfPen, pdfBrushX, cutBorder)

        'draw center line
        pdfGraphicsX.DrawLine(PdfPens.Silver, iCTR, 15, iCTR, 775)

        'horz lines
        pdfGraphicsX.DrawLine(PdfPens.Silver, cutL, imgH + iTP, cutR, imgH + iTP)
        pdfGraphicsX.DrawLine(PdfPens.Silver, cutL, (imgH * 2) + iTP, cutR, (imgH * 2) + iTP)
        pdfGraphicsX.DrawLine(PdfPens.Silver, cutL, (imgH * 3) + iTP, cutR, (imgH * 3) + iTP)
        pdfGraphicsX.DrawLine(PdfPens.Silver, cutL, (imgH * 4) + iTP, cutR, (imgH * 4) + iTP)
        pdfGraphicsX.DrawLine(PdfPens.Silver, cutL, (imgH * 5) + iTP, cutR, (imgH * 5) + iTP)

        Dim bm As Bitmap = New Bitmap(imgScrn.ClientSize.Width, imgScrn.ClientSize.Height)
        imgScrn.DrawToBitmap(bm, imgScrn.ClientRectangle)
        Dim pdfImageX = PdfImage.FromImage(bm)

        ' PLACE IMAGES on CANVAS
        pdfGraphicsX.DrawImage(pdfImageX, iLF, iTP, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF + imgW, iTP, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF, iTP + imgH, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF + imgW, iTP + imgH, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF, iTP + imgH * 2, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF + imgW, iTP + imgH * 2, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF, iTP + imgH * 3, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF + imgW, iTP + imgH * 3, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF, iTP + imgH * 4, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF + imgW, iTP + imgH * 4, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF, iTP + imgH * 5, imgW, imgH)
        pdfGraphicsX.DrawImage(pdfImageX, iLF + imgW, iTP + imgH * 5, imgW, imgH)

        'Save And close the document.
        pdfDoc.Save("pdfoutput.pdf")
        pdfDoc.Close(True)

        'open file
        System.Diagnostics.Process.Start("pdfoutput.pdf")

    End Sub

Other than the "jaggies" this basic beginnings of this app is working.
Any insight on how I can improve this would be appreciated.

Thanks

[technipixel]

FYI.... my app is returning a DPI of 96.

[technipixel]

I have defiantly figured out that the image is being stretched.
I was setting the w & h when drawing.
If I just leave off the width & height, the image is just placed at x-y position.

However...

My image is in pixels and the page values are in points.
How do i get both of them the same so I can code more accurately?

So, for example... the PicBox values reflect the actual image size.
But, it translates different when coded using a points measuring system.

Learning a lot!

More insight would be appreciated.

[paulg4ije]

I can't help with the PDF stuff but bear in mind that if you capture your image at 280 x 123 pixels and try to print it more than about an inch wide it is going to look pretty awful. You can't magically increase the DPI of a bitmap image; it is what it is.

[technipixel]

Okay... by properly getting the correct image dimensions for the output, it does fix the "jaggies" (pretty close at least)

However, just for my learning and to better code....

How can also always make sure that my DPI for images and output is always the same.

I understand what DPI and Screen Resolution is...

But, what do I need to do to consider each person's individual PC.

Thanks