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This window is presented when you elect to save a graph as an image file (BMP, GIF, JPG, PNG, or TIF) using the Save As menu command.
Width and Height
Enter the desired width and height of the image, in pixels. If the width or height are set to 0 and the Resolution setting is 100 or less dpi, the saved image will essentially be a screenshot. If both width and height are non-zero then the output image will be these dimensions unless the Resolution setting is greater than 100 dpi or if the Crop white space checkbox is checked. If Resolution is set to greater than 100 dpi, then the image dimensions (along with font sizes, line widths, symbol sizes, etc.) will be scaled by resolution/(screen resolution). For most Windows systems the display resolution is 96 dpi. If Crop white space is checked, the image will be the above dimensions minus any extraneous white space, with a 10-pixel white space border.
Crop white space
If checked, all but a 10-pixel white space border will be cropped from the image. If unchecked, the specified dimensions (subject to the Resolution setting) will be used and no cropping is performed.
Resolution
If the resolution is set greater than 100 then font sizes, line widths, the plot size and other dimensions as seen on the display will be scaled up by resolution/(screen resolution), so that the saved image will have the same proportions as the graph shown on your display.
For best results with a resolution setting greater than 100, always specify the plot size with a Size command or the Extents/Intervals/Size menu command. Otherwise you risk generating an Insufficient memory error for high resolution settings.
Color depth
Choose between 8-bit (256 colors), 24-bit (roughly 16 million colors), and 32-bit PNG with an alpha channel. GIF images are limited to 8-bit, JPG images are limited to 24-bit (and so these options are disabled for those formats).
For 32-bit PNG format, the plot background color will be set to transparent within the image. The antialiasing setting will be temporarily turned off if it was on, since removal of a single unique color would otherwise result in ugly artifacts. DPlot will temporarily turn off your system's "Smooth screen fonts" and/or ClearType settings, for the same reason that antialiasing is turned off.This format contains the same information as 8-bit GIF images with "Transparent GIF" turned on, but you may get better results when resizing these images than you would with GIFs.
NOTE: For images with many unique colors and/or antialiased lines and symbols and for 3D views of 3D/4D data in which one of the light source models is used, you will get better results saving the image as 24-bit PNG rather than 8-bits. If file size is paramount you can then use a dedicated image editor like Adobe Photoshop or Paint Shop Pro to reduce the color depth, with better results than you will get by saving to an 8-bit image in DPlot.
RLE-encoded (BMP only)
Only applicable to 8-bit BMP images. The 8-bit RLE format is generally suitable for most DPlot graphs and produces considerably smaller files than uncompressed bitmaps. However not all applications will support RLE bitmaps.
Improved color quantization
Only applicable for 8-bit images. If you are saving to an 8-bit color depth and your image has a colored background, you will generally get superior results if you check this box. For large images (large in this case defined as wider than 3500 pixels), the improved quantization method will be used regardless of your selection here, primarily because the default method performs poorly with large images.
Transparent GIF
Only applicable for GIF images. If checked, the plot background color will be set to transparent within the image. The antialiasing setting will be temporarily turned off if it was on, since removal of a single unique color would otherwise result in ugly artifacts. Depending on your purpose you might also set the number format for the X and Y axes to "None" and delete all text entries that are not essential (title and axis labels, etc.). DPlot will temporarily turn off your system's "Smooth screen fonts" and/or ClearType settings, for the same reason that antialiasing is turned off. This means that text entries in the image will suffer a bit from the jaggies.
JPEG quality
Only applicable for JPEG images. The "poor" setting produces the smallest files, though the quality will generally not be acceptable. "Lossless" has no visual artifacts typical of JPEG files, but the file size will be much larger than with any other setting. When DPlot is first installed, the default quality setting is "Good" (4th of the 5 settings).
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Related macro commands |
Page url:
https://www.dplot.com/help/index.htm?image_properties.htm
