LazPaint

Free cross-platform image editor with raster and vector layers, written in Lazarus (Free Pascal).

Can read layered files (lzp, ora, pdn, oXo, flat psd), multi-images (gif, ico, tiff), flat files (bmp, jpeg, pcx, png, tga, webp, xpm, xwd), raw images (dng, cr2, nef, arw...), vectorial (svg), 3D (obj). Has drawing tools, vector shapes, phong shading, curve adjustments, filters, render some textures, Python scripting. Uses Qt5 widgetset.

Features:

Files: read and write a variety of file formats, including layered bitmaps and 3D files.

Tools: many tools are available to draw on the layers.

Edit/Select: select parts of an image with antialiasing and modify the selection as a mask.

View: color window, layer stack window and toolbox window.

Command line: call LazPaint from a console.

Image manipulation:

An image can be resampled, flipped horizontally and vertically.

Smart zoom x3 : resize the image x3 and detects borders; this provides a useful zoom with ancient games sprites.

Color manipulation:

Colorize : set the color of an image while preserving intensities

Shift colors : cycle colors and change colorness (saturation)

Intensity : make colors lighter or darker without making them white

Lightness : make colors lighter or darker by making them whiter

Normalize : use the whole range of each color channel and alpha channel

Negative : invert colors (with gamma correction)

Linear negative : invert colors (without gamma correction)

Grayscale : converts colors to grayscale with gamma correction