Drops Manual

• Overview
  • Concepts
  • Usage
  • Main menu
• Loading/Saving
• Drawing modes
  • Color (col)
  • Pattern (map)
  • Light (lgt)
  • Pen (pen)
  • Shape (shp)
• Drawing tools
  • Freehand (Free)
  • Line
  • Zigzag line
  • Parable segment
  • Filled parable segment
  • Ellipse segment
  • Filled ellipse segment
  • Rectangle
  • Filled rectangle
  • Circle
  • Filled circle
  • Ellipse
  • Filled ellipse
  • Brush
  • Halo
  • Slanted ellipse
  • Slanted filled ellipse
  • Slanted rectangle
  • Slanted filled rectangle
  • Magnifier (Zoom)
  • Brightness, Gamma, Contrast (Light)
  • Replace color range with range (x-Col)
  • Replace color range with color (d-Col)
  • Turn block (Turn)
  • Fill block in shape (Shape)
  • Color locks (Locks, only Drops8)
  • Copy image area (Copy)
  • Paste
  • Flood fill (Fill)
  • Gradient fill (SFill)
  • Color range controlled fill (RFill)
  • Turn block by 90 degrees (Rot90)
  • Bold
  • Flip block (Flip)
  • Very simple text tool (Text)
  • Color control center (Color)
  • B-Splines (Spli.)
  • Undo
  • Switch drawing surfaces (x-Pic)
  • Switch to second menu (Menu2)
  • Bend block (Bend)
  • Pen painting (Pen)
  • Airbrush (Spray)
  • Filter (Filt.)
  • Resize (Scale)
  • Shear block (Shear)
  • Smear colors (Smear)
  • Function plotter (FPlot, experimental)
  • Texture map creation (TMaps, experimental)
  • Tile creation (Tiles)
  • Remove border/background (Debor, non-functional)
  • Cut without border (Crop)
  • Cut area (CutRe)
  • Outline (Outl.)
  • Switch to first menu (Menu1)
  • Perspective projection (PCorr, experimental)
  • Animation feature (Movie, experimental)
  • Trapezoid distortion (TZoom, experimental)
  • Slope alignment (Slope, experimental)
• Keyboard

Using Drops might be very different from other drawing tools. Drops is simple, direct and fast. There are a few common usages throughout the program. In the following the left mouse button is abbreviated to LMB, the middle mouse button is MMB and the left mouse button is named RMB.

• LMB starts/chooses/activates things.
• During most drawing operations you can pick a new drawing color from the image by using the MMB.
• The right mouse button breaks an action and finally brings you back to the main menu. If there are several nested actions, you need to press the RMB a few times to get back to the main menu.

Another pretty basic concept in drops is the block. This is a rectangular image area taken with the (see copy tool) from the image or loaded from a file. The block determines the pattern for the drawing mode pattern (map). The block also is the data base for the pen tool and the pen-drawmode can take pen data from the block. To rotate or flip image areas, the must be copied as block. Scaling is a bit different, it takes an area from the image, scales it and stores the result as block.

Using Drops is usually a sequence like this:

• Choose a tool from the main menu by clicking the tools button. This hides the menu and brings the image to front.
• Work with the tool on the image.
• Get back to the main menu to choose another tool, drawing mode or color. Please note that you can pick colors while painting with MMB, this is usually quicker than going back to the main menu to choose another color.

The main menu contains buttons for all tools. below the main menu there is the current color map displayed. Click a color with LMB to select this color for painting (foreground color). A click with RMB onto a color marks this color as the new background color. Foreground and background colors may be the same color. The pen tool treats the background color as transparent. The text tool writes text according to foreground and background colors.

At the right border of the drops window you'll find a few useful things.

• Top right is the real time magnifier which always displays the area below the mouse pointer magnified.
• Below the real time magnifier there is the coordinate display which shows always the current mouse position.
• Below that is the context sensitive short help frame. The short help frame always gives hints which actions are available at this point. It usually list actions bound to keys and mouse buttons. If you have problems using a tool, take a look at this, it will guide you.

Drops can load and save images, color maps and image blocks.

Drops can read PNG, JPEG, TGA, PPM, GIF and LBM images. (Also a internal format called RAW).

Drops can write PNG, JPEG and PPM images. (Also it can write RAW images and images as C header files, but this is experimental).

Drops autodetects image formats during loading. Format detection is done by reading the image, not by using the name extension. I.e. if you rename 'blubber.jpg' to 'blubber.png' Drops will still recognize that this is a PNG file and use the correct image loader.

Drops for Linux can load images stored in gzip compressed format. I.e. frogjump.ppm.gz will first be decompressed (using gunzip) and then loaded. The file is not affected from decompression, it remains compressed. Drops for Linux can also compress images during saving, if the name ends with .gz. I.e. After loading frogjump.ppm.gz you can save it to the file and drops will save it in ppm format and then compress the file using gzip. (Note: if you use Windrops and have gzip and gunzip installed this might work also, but it is untested).

It detects the desired format from the name during saving (i.e. if you tell to save a image to a file called 'sunrise.png' it will save it as a PNG image.) If drops does not recognize the filename extension, it ask which format to use.

Drops uses drawing modes to affect the operation of all drawing tools. The modes affect the way the tools modify the image. Often you'll find that if Drops seems to lack a tool, you just did not use the appropriate drawing mode.

This is the basic drawing mode. The drawing tools apply the chosen color to the image. This mode is automatically selected if a new color is chosen in the color map.

Instead of applying the same color to each painted pixel, a pattern is used. The pattern is taken from the block.

Instead of applying color to the image this affects the brightness of the painted spots. It may lighten or darken. This can be adjusted by setting the Lg value from the rightmost menu colum.

Instead of painting single pixels, a bigger pen is used. Pen shape and color are determined by the settings from the 'Pen' dropdown menu.

Similar to mode pen, but only the shape of the pen is used. The chosen color is used for painting.

The freehand tool lets you draw arbitrary shapes. Press LMB to start painting.

The line tool lets you draw straight lines. Press LMB to start a line, LMB again to finish the line. Now you can move the line. Place the line with LMB. If you want you can hold LMB pressed and drag the mouse to paint with the line.

The zigzag line tool lets you draw zigzag lines. Press LMB to start a line, LMB again to place a corner. Press RMB to stop adding segments.

The parable tool lets you draw curved lines. Press LMB to start a line, LMB again to place the end. Move the mouse to curve the line. Press LMB to accept the line, RMB to discard the line.

Similar to the parable segment tool, just uses a different formula for the curve and you get different curves from this.

The rectangle tool lets you draw rectangles. Press LMB to start a rectangle, LMB again to finish the rectangle. Now you can move the rectangle. Place the rectangle with LMB. If you want you can hold LMB pressed and drag the mouse to paint with the rectangle.

Usage is the same as the rectangle tool, except that this tool draws circles.

Usage is the same as the rectangle tool, except that this tool draws ellipses.

The brush tool allows to paint with a large filled rectangle. Most often used to color or wipe big areas quickly. For detailed work the pen tool is much better. To use the brush drag the rubber band box to the appropriate size and click LMB. To paint with the brush, press LMB and drag the mouse.

The halo tool is a filling tool which draws color gradients between the borders. This gives the borders a 'halo' effect. in Drops8 the results are most often not very pleasant because the colormap only in rare cases contains all needed colors for the gradients. Results in Drops16 are usually much better. The results depend strongly on clever chosen border colors and shapes. Probably you need to experiment a bit with this tool until you get the results you need. Pre-drawn colored areas inside the shape might be useful to guide the color gradients.

Usage is very similar to the parable segment tool. This tool allows to paint slanted and perspectively distorted ellipses (useful for drawing cut tubes).

Usage is very similar to the parable segment tool. This tool allows to paint slanted and distorted rectangles.

The magnifier can zoom an image area. You can then work on the zoomed area with all tools. At the lower right corner a real-size version of the zoomed area is displayed. This lets you control your work in real size look, handy for working on small things with shall look realistic.

A second LMB click on the zoom tool brings you back to the unzoomed image view. While working zoomed, no undo is available. But you con undo all changes of a zoom session after returning to unzoomed mode by using the undo tool.

You can switch between a grid mode and solid zoom by changing the Lp: setting in the rightmost main menu column. Lp: Grd selects grid mode, Lp: Blk selects solid mode.

This is actually a collection of tools which work very similar. You can choose one of the operations brightness, gamma or contrast correction and apply this operation to one or all of the RGB color channels. Operations affect the whole image. In Drops8 you can choose if the transform should be applied to the image or the color map. In Drops16 always the image is transformed.

You can use this tools to correct color and lightness problems of scanned images or digital photos. Some of the operations are also available as filters.

This tool can replace a color range with another color range or a pattern. In drawing mode color (col) it replaces color ranges with color ranges. In drawing mode pattern (map) it replaces color rages by a pattern, taken from the block (see copy). The pattern is shaded according to the lightness of the replaced color area.

This works pretty much like the x-Col tool but instead of replacing a color range with another range or a shaded pattern it replaces the range with a single color or a plain pattern.

This tool allows to turn the block interactively. You can choose from interpolated operation or quick operation. Turning with interpolation is pretty slow. You can also choose if the full image shall be sued as background during the turn operation. Having a background image also slows down the operation, but less than using interpolation.

The block can be filled into a arbitrary shape. It might even have inner holes. The Block is warped into the shape and around the holes. If you choose 'horizontal' mode, the block is cut vertically at the places where holes exist and flows horizontally around the holes. 'Vertical mode' makes horizontal cuts and flows vertical. 'Both' is a combination of both with might or might not be useful.

This is basically a very mighty tool, but it is very tricky to use.

Locked colors are immutable. This means no drawing operation can affect locked colors. If you want to have immutable areas in your image and they have distinct color you can use color locks to make the areas immutable.

To actually activate color locks, click the "Lk:" setting from the main menu. If it says 'Lk: on' the locks are activated. 'Lk: off' means locks are disabled. This is the default because the locks need extra processing time during painting.

The locks use colormap indices to lock colors. Therefore they only work in Drops8.

The copy tool copies an rectangular image area into the block. The block can be pasted into the image again, but also affects the pattern used in drawing mode pattern (map) and is the source for the pens shape and colors. Drops can store only one block at a time. Copying a new area destroys the former block. Copied blocks can be saved to image files.

The paste tool copies the block back into the image. Drops can load the block from an image file or copy it from the image.

If you want to copy the block back into the image, but block pixels of background color to be transparent use the pen tool in mode map.

The flood fill tool can fill areas. In drawing mode color (col), it fills an area with a color. In drawing mode pattern (map) it fills an area with a pattern, taken from the block (see copy). In mode light (lgt) if changes the areas brightness. Modes pen (pen) and shape (shp) are not terribly useful for the flood fill tool.

To determine which areas to fill the fill tool matches colors. The base color is the color of the point where the tool was applied. Flood fill fill all adjacent points from this point which have a similar enough color to this point. Which colors are similar enough is determined by the fill tolerance setting.

You can change the fill tolerance in the rightmost column of the main menu. It's the box labeled 'Ft:'. A fill tolerance of 0 means exact match, a tolerance above zero matches similar colors too. The higher the number the less precise the match needs to be. A fill tolerance of -1 means to match every color but the currently chosen color.

The gradient fill tool can fill areas with color gradients. It knows about horizontal, vertical, bidirectional and contour aligned color gradients. The examples above are contour aligned color gradients. This tool can also apply some randomization to the color gradient, breaking the surface, making it look rough.

The gradient fill tool is supposed to fill patterns in drawing mode pattern (map). The pattern is supposed to be filled shaded, according to a lightness gradient. This does not work in Drops v2.19

This is very similar to the flood fill tool. The only difference is that the area to be filled is determined by a color range instead of a single color. This tool often needs a higher fill tolerance setting than the other fill tool.

You can change the fill tolerance in the rightmost column of the main menu. It's the box labeled 'Ft:'. A fill tolerance of 0 means exact match, a tolerance above zero matches similar colors too. (In case of RFill it matches colors similar to any color in the range). The higher the number the less precise the match needs to be. A fill tolerance of -1 means to match every color but the currently chosen color.

This turns the block by 90 degrees, to the left, or to the right.

This tool enlargens areas of foreground color in horizontal, vertical or both directions.

This tool allows to flip the block vertically, horizontally or in both directions.

A very simple text tool. You can write text into the image, in exactly one font font and the chosen foreground and background colors.

A B-Spline is a smooth curve. The curve is controlled by a set of points which attract the curve. To draw a B-Spline you first place a few points, each by pressing the LMB. If you have placed all desired points press the RMB. Now you can move the points: grab one with the LMB and drag it. The B-Spline will follow the moves. If the B-Spline is of the desired shape, press RMB.

Now you have a final chance to judge: press LMB to accept the B-Spline or RMB to undo it.

This resets all changes to the image when you left the main menu last time.

Drops features two drawing surfaces. Use this to switch to the other drawing surface. The contents of the second surface are lost if a new image is loaded.

This tool can bend the block aligned to elliptic, parabolic and triangular shapes in horizontal or vertical direction.

The airbrush tool sprays pixels onto the image. Usually the sprayed area is circular and the spray density is higher in the middle of that area.

You can change the overall spray density by changing the "Sd:" setting from the main menu. You can switch to a recangular spray by changing the "Sp:" setting from the main menu. Both settings are found in the rightmost column.

This allows to shear the block along any of the axes. It converts a rectangular block into an arbitrary tetragon. If you need a more precise alignment along one axe only you should try the slope alignment tool

Works a bit like the airbrush tool, but instead of adding new color to the image, it moves pixels around. This can be useed to give sharp edges a jagged look or to randomize smooth color gradients.

Works like the copy tool, but removes any border from around the image.

Works like the copy tool, but lets you cut an area of fixed size. You can enter the size pixel precise, say 64x64 and then move a fram of this size over the area you want to cut. Use this if you need to copy areas of a certain size.

This tool draws an outline around an arbitrary shape.